Conference on Neutrino and Nuclear Physics (CNNP2020) Arabella Hotel and Spa, South Africa, 24-28 February 2020

23 Feb 2020, 16:00 → 28 Feb 2020, 22:30 Africa/Johannesburg

Retief Neveling (iThemba LABS)

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     Approved videos from invited talks can now be seen on the CNNP2020 YouTube channel

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The international Conference on Neutrino and Nuclear Physics 2020 (CNNP2020) will be held at the Arabella Hotel and Spa in the Kogelberg Biosphere near Cape Town (South Africa) from 24-28 February 2020 and will be hosted by iThemba LABS. The Kogelberg Biosphere is internationally famed for its natural beauty and biodiversity, and is within an hour's drive from Cape Town.

The main objective of the Conference on Neutrino and Nuclear Physics is to promote collaboration between scientists from the fields of nuclear, neutrino, astro and dark-matter physics, and to create an environment where experiments and theories in which nuclear physics aspects are particularly relevant can be discussed. 

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A preliminary list of the topics to be discussed during the conference include:

•     Nuclear double beta decays
•     Nuclear structure in connection with neutrino physics
•     Nuclear reactions as probes for weak decays
•     Neutrino-nucleus interaction at low and high energies
•     Supernova models and detection of supernova neutrinos
•     Solar models and detection of solar neutrinos
•     Direct and indirect dark-matter searches
•     Rare beta decays of nuclei for measurements of neutrino-mass
•     Neutrino oscillations and matter effects
•     Anomalies in reactor neutrinos
•     New detection technologies related to the field

The very successful inaugural CNNP2017 conference was held in Catania in October 2017. CNNP2020 will be the second conference in the series and aims to build upon the foundation of CNNP2017 to bring together people working at the intersections of different fields to exchange ideas and results.

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Booking Form-iThemba LABS.doc

CNNP2020_ConferenceGuide.pdf

cnnp2020-fourth-circular.pdf

cnnp2020-second-circular.pdf

cnnp2020-third-circular.pdf

cnnp-poster-final.pdf

Final_CNNP2020_Conference_Guide.pdf

first-circular-cnnp2020.pdf

Sponsorship_and_Exhibition_Options_CNNP2020.pdf

Sunday, 23 February

16:00 → 18:00 Registration

18:30 → 20:30 Welcome Function

Monday, 24 February

08:00 → 08:30 Registration

08:30 → 09:00 Opening and Welcome by Dr Faïçal Azaiez - Director of iThemba LABS

09:00 → 10:30 Invited Talks

Convener: Chair: Francesco Cappuzzello (University of Catania and INFN-LNS, Italy)

09:00 Recent results and perspectives on beta decay, double beta decay and lepton flavour violation

The lepton sector of the Standard Model is a very important and interesting field to search for new physics beyond the standard model. As we know that quarks and neutrinos are mixing it is an open question why the charged leptons are now. This stimulates the search for charge lepton violation (CLFV). In addition, neutrino-less double beta decay would violate total lepton number by 2 and prove that neutrinos are their own antiparticle. The obtained half-life can be linked to a potential Majorana neutrino mass. This is providing a complementary measurement to normal beta decay where new interesting results are obtained.
This talk will shortly review the current situation in this area of research, required support from theory and an outlook into the future.

Speaker: Kai Zuber (Technical University Dresden)

CNNP-Zuber.pdf

09:30 Nuclear processes and effective weak couplings

The axial-type of weak couplings seem to be renormalized in medium-heavy and heavy nuclei as suggested by analyses of nuclear beta and double beta decays, nuclear muon capture, charge-exchange reactions and low-energy neutrino-nucleus scattering [1]. Also some calculations suggest that also the vector-type of couplings could attain effective values in nuclei [2,3]. The possible variation of the values of weak couplings as functions of the nuclear mass number affects the information deduced from the possible future measurements of the half-lives of neutrinoless double beta ($0\nu\beta\beta$) decays [4],
nuclear muon captures, electron and antineutrino spectra of medium-mass fission fragments in nuclear reactors, etc. In particular, there could be direct effects on the reactor antineutrino anomaly and the Gallium anomaly [1].

Studies of the $0\nu\beta\beta$ decays of nuclei are of paramount importance in order to learn about the basic properties of the neutrino. An appealing way to probe this decay rather directly is the nuclear muon capture, since it operates in the same momentum-exchange region as the $0\nu\beta\beta$ decays. Recent results on the muon capture rate on $^{100}$Mo [5] indicate that the muon-capture calculations are able to reproduce the measured capture strength function in a quite satisfactory way.

In my contribution I present an overview of the problem of effective weak couplings and discuss the relation of the nuclear muon capture to $0\nu\beta\beta$ processes.

REFERENCES

[1] H. Ejiri, J. Suhonen and K. Zuber, Neutrino-nuclear responses for astro-neutrinos,
single beta decays and double beta decays, Phys. Rep. 797 (2019) 1-102.
[2] J. Suhonen, Value of the axial-vector coupling strength in $\beta$ and $\beta\beta$ decays: A review, Front. Phys. 5 (2017) 55.
[3] J. Suhonen and J. Kostensalo, Double $\beta$ decay and the axial strength, Front. Phys. 7 (2019) 29.
[4] J. Suhonen, Impact of the quenching of $g_{\rm A}$ on the sensitivity of
$0\nu\beta\beta$ experiments, Phys. Rev. C 96 (2017) 055501.
[5] L. Jokiniemi, J. Suhonen, H. Ejiri and I. H. Hashim, Pinning down the strength
function for ordinary muon capture on $^{100}$Mo, Phys. Lett. B 794 (2019) 143-147.

Speaker: Jouni Suhonen (University of Jyväskylä)

CNNP2020-Suhonen.pdf

10:00 The role of neutrino-nucleus reactions in supernova nucleosynthesis

Neutrinos play an important role for the supernova dynamics and the
associated nucleosynthesis. During collapse, electron neutrinos, produced
by electron capture on nuclei, dominate, while all neutrino families are
being produced during the cooling phase of the protoneutron star.

Neutrinos are crucial for the explosive nucleosynthesis. At first, by
interaction with free nucleons they determine the proton-to-neutron ratio
of the ejected matter which is crucial for the subsequent
nucleosynthesis. Modern supernova simulations indicate that the ejected
matter is not sufficiently neutron rich to support an r-process which also
produces the solar abundances in the third r-process peak.

Neutrino-induced spallation reactions on abundant nuclei in the outer
stellar shells are responsible for the production of selected nuclides
(neutrino nucleosynthesis). Recently the first study of neutrino
nucleosynthesis has been presented which considers the time-dependence
of the neutrino emission including the neutrino burst, the accretion phase
and the cooling phase as well as changes in the spectral forms of the
neutrinos.

Speaker: Karlheinz Langanke (GSI Darmstadt)

Langanke_Slides.ppt

10:30 → 11:00 Coffee/Tea Break

11:00 → 13:00 Invited Talks

Convener: Chair: Elena Aprile (Columbia University)

11:00 New results from the CUORE experiment

The Cryogenic Underground Observatory for Rare Events (CUORE) is the first bolometric experiment searching for neutrinoless double-beta decay (0νββ) that has been able to reach the one-ton scale. The detector, located at the Laboratori Nazionali del Gran Sasso in Italy, consists of an array of 988 TeO$_{2}$ crystals arranged in a compact cylindrical structure of 19 towers. The construction of the experiment was completed in August 2016 with the installation of all towers in the cryostat. CUORE achieved its first physics data run in 2017 corresponding to a TeO$_{2}$ exposure of 86.3 kg∙yr and a median statistical sensitivity to a $^{130}$Te 0νββ half-life of 7.0 × 10$^{24}$ yr. Following multiple optimization campaigns in 2018, CUORE is currently in stable operating mode and has accumulated data corresponding to a TeO$_{2}$ exposure approaching 500 kg∙yr. In this talk, we present the updated 0νββ results of CUORE, as well as review the detector performance. We finally give an update of the CUORE background model and the measurement of the $^{130}$Te two neutrino double-beta decay (2νββ) half-life.

Speaker: Giovanni Benato (LNGS-INFN)

GiovanniBenato_CNNP2020.pdf

11:30 Status of the SuperNEMO Experiment

The SuperNEMO Experiment is designed to search for neutrinoless double beta decays of the Se-82 isotope. The detector employs the multi-observable tracking-and-calorimetry technique pioneered by the NEMO-3 Experiment. Electrons originating from double beta decays of an isotope in thin isotopic foils are tracked in wire tracking chambers and their energy is measured by large scintillator blocks. The topology, timing, and energy provide a powerful means of identifying and measuring the final state of decays. The technique is also very effective in rejecting backgrounds due mostly to traces of natural radioactivity in foils and detector materials. The SuperNEMO Demonstrator module is currently being commissioned at the Modane Underground Laboratory in the Frejus Tunnel. We will discuss details of the detector elements, the latest status of the experiment, and the physics reach.

Speaker: Alessandro Minotti (LAPP - IN2P3)

TalkCNNP2020_Minotti_Small.pdf

12:00 The nEXO double-beta decay experiment

The search for neutrinoless double-beta decay represents one of the most exciting
opportunities to explore physics beyond the Standard Model. The knowledge that
neutrinos are massive particles, yet, with masses that are many orders of magnitude
smaller than those of charged fermions, provides encouragement to further push
the sensitivity of these experiments.

nEXO is a 5-tonne detector based on the isotope 136Xe in a single phase, liquid
time projection chamber. Its design is based on EXO-200, the first 100kg-class
experiment to take data, demonstrating the power of a monolithic detector with
good energy resolution and superior topological event reconstruction. nEXO is
expected to reach a half-life sensitivity of about 10^28 years, covering substantial
discovery space. The detector includes several state-of-the-art components but,
at the same time, offers a conservative approach in which the background estimate
is solidly grounded on existing materials and reliable simulation tools. In this talk
the nEXO design and sensitivity reach will be discussed.

Speaker: Giorgio Gratta (Stanford University)

Gratta nEXO_CNNP_CapeTownL_Feb2020.pdf

12:30 MAJORANA, LEGEND, and the future of the search for Neutrinoless Double-Beta Decay in Ge-76

The MAJORANA collaboration is searching for neutrinoless double-beta ($0\nu\beta\beta$) decay in $^{76}$Ge using modular arrays of enriched, high-purity Ge detectors. The MAJORANA DEMONSTRATOR consists of an array of 44 kg of high-purity Ge detectors with a p-type point contact geometry currently operating in the Sanford Underground Research Facility in Lead, South Dakota. The ultra-low background and world-leading energy resolution achieved by the MAJORANA DEMONSTRATOR enable a sensitive $0\nu\beta\beta$ decay search, as well as additional searches for physics beyond the Standard Model. The Large Enriched Germanium Experiment for Neutrinoless Double-Beta Decay (LEGEND) will combine the best techniques from the DEMONSTRATOR and the Germanium Detector Array (GERDA) to reach even higher sensitivities to $0\nu\beta\beta$ decay. The LEGEND collaboration is pursuing a phased approach to a tonne-scale $^{76}$Ge experiment, with ultimate discovery potential at a half-life beyond $10^{28}$ years. The first phase, LEGEND-200, is the deployment of 200 kg of enriched $^{76}$Ge detectors in the existing GERDA cryostat at the LNGS underground lab in Italy. LEGEND-200, scheduled to start operation in 2021, will use GERDA and MAJORANA enriched detectors and newly developed inverted coax point contact detectors. The MAJORANA DEMONSTRATOR's latest results will be presented as well as the construction status of LEGEND-200, ongoing LEGEND tonne-scale R&D, and the physics outlook of the LEGEND experimental program.

Speaker: David Hervas (University of North Carolina at Chapel Hill)

Hervas_Slides.pptx

13:00 → 14:00 Lunch

14:00 → 15:40 Contributed Talks

Conveners: Main Venue Chair: Clementina Agodi (INFN.LNS) , Parallel Venue Chair: Javier Menendez (University of Barcelona)

14:00 Dark Matter searches at Belle II

The Belle II experiment at the SuperKEKB energy-asymmetric $e^+ e^-$ collider is a substantial upgrade of the B factory facility at the Japanese KEK laboratory. The design luminosity of the machine is $8\times 10^{35}$ cm$^{-2}$s$^{-1}$ and the Belle II experiment aims to record 50 ab$^{-1}$ of data, a factor of 50 more than its predecessor. Main operation of SuperKEKB has started in March 2019, with the full detector installed; this first running period ended in July. The machine reached a peak luminosity of $1.2\times 10^{34}$ cm$^{-2}$s$^{-1}$, and Belle II recorded a data sample of about 6.5 fb$^{-1}$. Data taking will resume in October 2019. Already this early data set, with specifically designed triggers, offers the possibility to search for a large variety of dark sector particles in the GeV mass range, complementary to LHC and to dedicated low energy experiments; these searches will benefit from more data which will be accumulated in the upcoming Fall/Winter run. This talk will review the state of the dark sector searches at Belle II with a focus on the discovery potential of the early data, and show the first results

Speaker: Marcello Campajola (INFN-Napoli)

CAMPAJOLA_CNNP_v1.pdf

14:00 Searching for neutrinoless double beta of 100Mo: the CUPID-Mo experiment

$^{100}$Mo deployed in the form of enriched Li$_{2}$ MoO$_{4}$ crystals can be used as a promising scintillating bolometer to search for 0$\nu\beta\beta$ in a tonne-scale experiment. In this talk we will review the properties of this target crystal and achieved bolometric detector performances that make it the baseline choice for CUPID (CUORE Upgrade with Particle ID).
CUPID-Mo, installed in the underground laboratory of Modane, consists of an array of 20 enriched ~0.2 kg Li2MoO4 crystals equipped with 20 cryogenic Ge bolometers to discriminate alpha from beta/gamma events by the detection of both heat and scintillation light signals. The commissioning has started in december 2018 and we have switched to routine data taking in spring 2019. In this talk, we will present results confirming an excellent bolometric performance of $\sim$5-6 keV energy resolution (FWHM) at 2615 keV, full alpha to beta gamma separation and improved estimates on the radiopurity of the crystals. We will also report on the background level observed in the region of interest and give a competitive limit on the neutrinoless double-beta decay half-life of Mo-100 as well the most precise measurement of the 2-neutrino decay mode. We will conclude with an expectation of the sensitivity of CUPID-Mo and prospects for CUPID.

Speaker: Claudia Nones

14:20 CUPID-0: a double-readout cryogenic detector for DBD

A convincing observation of neutrino-less double beta decay (0𝜈DBD) relies on the possibility of operating high-energy resolution detectors in background-free conditions.
Scintillating cryogenic calorimeters are one of the most promising tools to fulfill the requirements for a next-generation experiment. Several steps have been taken to demonstrate the maturity of this technique, starting form the successful experience of CUPID-0.
The CUPID-0 experiment demonstrated the complete rejection of the dominant alpha background measuring the lowest counting rate in the region of interest for this technique. Furthermore, the most stringent limit on the Se-82 0𝜈DBD was established running 26 ZnSe crystals during two years of continuous detector operation.
In this contribution we present the final results of CUPID-0 Phase I including a detailed model of the background, the measurement of the 2𝜈DBD half-life and the evidence that this nuclear transition is single state dominated. The first results obtained after the upgrade of the detector in 2019 are presented as well.

Speaker: Lorenzo Pagnanini

14:20 EDELWEISS: searching for low-mass dark matter particles with germanium low-temperature detectors

EDELWEISS is a direct dark matter search experiment aiming at the detection of WIMPS and other candidates as the composition of the galactic dark matter halo. The EDELWEISS detection method is based on arrays of germanium mono-crystals operated at temperatures around or below 20 mK. Energy deposited in the crystals by particle interactions are read out simultaneously by thermal sensors, which collect the phonon component of the signal, and by surface electrodes, which collect the ionization component. This hybrid detection method is extremely powerful for background reduction. The EDELWEISS devices are operated in a low-radioactivity heavily-shielded dilution refrigerator installed in the deepest European underground laboratory in Modane (France). Recently, results have been achieved also with an extremely low-noise set up installed above ground.
The versatile and highly performing technology adopted by EDELWEISS opens new possibilities to detect signals induced by either electrons or nuclear recoils. EDELWEISS has developed a rich program to look for DM candidates with masses below 1 GeV and down to the MeV range (EDELWEISS SubGeV program), in a region of the parameter space where low-temperature detectors are extremely competitive. There is an increasing interest in this mass range motivated by the lack of evidence of new physics at LHC (e.g. SUSY), which pushes to look beyond the standard WIMP dark matter scenario
Detectors are operated in two modes, according to the voltage magnitude applied to the ionization electrodes. In the low-voltage mode, discrimination between nuclear and electron recoils is maintained, with threshold down to 50 eV (electron equivalent) in prospects. In the high-voltage mode, detection of single electron-hole pair in massive detectors is possible.
We will report both on the promising technological advancements in these detection regimes and on recent results about low-mass candidates. In particular, we will present results on Axion-Like Particles in the keV range and will report the attainment of the first sub-GeV spin-independent dark matter limit based on a germanium target. The search has been extended to Strongly Interacting Particles (SIMP) down to masses of 45 MeV by exploiting the Migdal effect. Results on SIMPs with spin-dependent interactions will also be presented.

Speaker: Andrea Giuliani (CNRS/CSNSM)

14:40 DELight – Searching for light dark matter using superfluid helium

The Direct search Experiment for Light Dark Matter (DELight) aims to develop a novel detector technology for the search for light dark matter based on the properties of the superfluid phase of the inert gas 4He. This detector uses the purest material imaginable, provides multiple independent signals for background suppression, has the potential to exploit directionality for event identification, and offers the ability to extend the sensitivity of direct dark matter search to the MeV range. In the first phase, we will build a 10-liter prototype detector with metallic magnetic calorimeters (MMCs) as photon and phonon sensors to investigate the signal threshold that can be reliably detected and to study the directional dependence of the quantum evaporation of He atoms on the energy and mass of the scattering particle. Here we will discuss the physics and the potential of such a detector for light dark matter as well as the goals and long-term perspective of DELight.

Speaker: Christian Enss (Kirchhoff Institute for Physics, Heidelberg University)

DELight_CNNP.pdf

14:40 Theoretical description of half-lives and electron spectra for higher order forbidden non-unique $\beta$ decays

Theoretical description of half-lives and electron spectra for higher order forbidden non-unique $\beta$ decays

Anil Kumar and Praveen C. Srivastava

Department of Physics, Indian Institute of Technology Roorkee,
Roorkee 247 667, India

In this work we have calculated log$ft$ and half-lives values of the higher order forbidden $\beta$-decays for selected nuclei [for e.g. $^{87}$Rb($3/2^-$) $\rightarrow$ $^{87}$Sr($9/2^+$)] in the framework of the nuclear shell model [1-3]. In the present study, we have included next-to-leading-order terms [4-6] in the shape functions to see their effect in the calculated half-lives and $\beta$ (or electron) spectra. The role of effective value of axial-vector coupling constant ($g_A$) in half-lives and $\beta$ spectra for higher-forbidden beta decay are very important. The $\beta^-$-spectrum of the fourth-forbidden non-unique decays of $^{113}$Cd and $^{115}$In strongly depends on the effective value of $g_A$ [4,7]. In our study we will report the spectrum-shape method (SSM) for electron spectra with the effective value of $g_A$. With the SSM, it is possible to extract information of effective value of the weak coupling constant by comparing the theoretical and experimental $\beta$ electron spectra of forbidden non-unique $\beta$-decays.

[1] H. Behrens and W. Bühring, Electron Radial Wave Functions
and Nuclear Beta-decay (Clarendon Press, Oxford, 1982).

[2] H. F. Schopper, Weak Interactions and Nuclear Beta Decay
(North-Holland, Amsterdam, 1966).

[3] J. Suhonen, From Nucleons to Nucleus: Concepts of Microscopic
Nuclear Theory (Springer, Berlin, 2007).

[4] M. Haaranen, J. Kotila and J. Suhonen, Spectrum-shape method and the next-to-leading-order terms of $\beta$-decays shape factor, Phys. Rev. C {\bf 95}, 024327 (2017).

[5] M.Haaranen, P. C. Srivastava and J. Suhonen, Forbidden nonunique $\beta$ decays and effective values of coupling constants, Phys. Rev. C {\bf 93}, 034308 (2016).

[6] J. Kostensalo, M. Haaranen, and J. Suhonen, Electron spectra in forbidden $\beta$ decays and the quenching of the weak axial-vector coupling constant $g_A$, Phys. Rev. C {\bf 95}, 044313 (2017).

[7] M. T. Mustonen, M. Aunola, and J. Suhonen, Theoretical description of the fourth-forbidden non-unique $\beta$ decays of $^{113}$Cd and $^{115}$In, Phys. Rev. C {\bf 73},
054301 (2006).

Speaker: Anil Kumar (Indian Institute of Technology, Roorkee, India)

Anil_CNNP2020.pdf

15:00 -

15:00 Enlightening the dark with XENON1T and looking forward to XENONnT

The most recent results of the XENON1T direct dark matter detector will be presented. XENON1T was a two-phase xenon TPC using 248 low radioactivity PMTs to detect scintillation signals in a 2-ton active liquid xenon target. The detector was operational between 2016 and 2018 at the Laboratori Nazionale del Gran Sasso with continuously improving xenon purity and reduction of the internal Kr-85 background source. In addition to WIMP searches, XENON1T also produced important results on nuclear processes, such as the double electron capture of 124Xe, and is sensitive to flavour independent measurements of solar and supernova neutrinos. The status of the successor experiment, XENONnT will be discussed, as well as projections for WIMP and neutrinoless double beta decay searches.

Speaker: Christian Wittweg

CNNP_2020_Wittweg_upload.pdf

15:20 -

15:20 ReD: a SiPM based LAr TPC for directionality studies

The Recoil Directionality project (ReD) within the DarkSide Collaboration aims to characterize the light and charge response of a liquid argon (LAr) dual-phase Time Projection Chamber (TPC) to neutron-induced nuclear recoils. The main goal of the project is to probe for the possible directional dependence suggested by the SCENE experiment. Furthermore, ReD will have the possibility to study the response of a LAr TPC to very low-energy nuclear recoils. Sensitivity to directionality and to low-energy recoils are both key assets for future argon-based experiments looking for Dark Matter in the form of WIMPs.

ReD consists in the irradiation of a miniaturized LAr TPC with a neutron beam at the INFN, Laboratori Nazionali del Sud (LNS), Catania. Neutrons are produced via the reaction p($^7$Li,$^7$Be)n from a primary $^7$Li beam delivered by the TANDEM accelerator of LNS. A $\Delta$E/E telescope, made by two Si detectors, identifies the charged particles ($^7$Be) which accompany the neutrons emitted towards the TPC. The core detector of ReD is a small custom-made double phase LAr TPC, having sensitive volume of 5×5×5 cm$^3$. The ReD TPC uses all the innovative features of the DarkSide-20k design: in particular the optoelectronic readout based on SiPM and the cryogenic electronics. It is thus a valuable test bench of the technology which is being developed for DarkSide-20k and for the future project Argo. Neutrons scattered from the TPC are eventually detected by using an array of nine 3-inch liquid scintillator (LSci) detectors. All LSci are placed such to tag recoils having the same energy, i.e. the same scattering angle with respect to the incident neutron, but different angle with respect to the drift field of the LAr TPC, thus allowing to search for a possible directional response.
The integration of the three detector systems was performed within several test beams performed in 2018-2019, using the TANDEM accelerator of LNS. Neutrons were produced by sending a $^7$Li 28 MeV beam onto a set of CH$_2$ targets having thickness between 250 and 400 $\mu$g/cm$^2$.

The physics measurement is expected to take place during the early months of 2020. This contribution will report about the current status of the project, including the physics results possibly obtained in the meanwhile, and on the short- and medium-term plans. The feasibility is also discussed of a wider-purpose facility at INFN-LNS, targeted to the calibration of detectors of interest for Dark Matter or rare events searches with tagged neutrons.

Speaker: Luciano Pandola (INFN - Laboratori Nazionali del Sud)

Pandola-ReD.pdf

15:40 → 15:50 Conference Photograph

15:50 → 16:10 Coffee/Tea Break

16:10 → 17:10 Invited Talks

Convener: Chair: Federico Nova (Rutherford Appleton Laboratory)

16:10 Neutrinos from CCSN and the contribution of nuclear experiments

The impact of different microphysics inputs on the dynamics of core collapse
during infall and early post-bounce is studied performing spherically symmetric simulations in general relativity using a multigroup scheme for neutrino transport and full nuclear distributions in extended nuclear statistical equilibrium models.
We show that the individual EC rates are the most important source of uncertainty in the simulations, and establish a list of the most important nuclei to be studied in order to constrain the global rates.
The effect on the collapse dynamics and neutrino luminosity is studied.

Speaker: Francesca Gulminelli (LPC Caen and University of Caen, France)

gulminelli.pdf

16:40 HALO-1kT - Status and Design

HALO-1kT is a lead-based supernova neutrino detector proposed for the Laboratori Nazionali del Gran Sasso (LNGS). By utilizing lead from the decommissioning of the OPERA detector at LNGS, HALO-1kT will improve of the sensitivity of the Helium and Lead Observatory (HALO), that has been running in SNOLAB in Canada for the past 7 years, by a factor of ~25. The lead-based neutrino detection technology takes advantage of the large neutrino-nuclear cross sections for lead, and Pauli-blocking of the anti-electron-neutrino charged current channel, to offer a robust, low cost and low maintenance electron-neutrino-sensitive detector that complements water Cherenkov and liquid scintillator neutrino detectors. Neutrino detection is through charged and neutral current interactions with the lead nuclei that expel neutrinos that a subsequently detected with high efficiency in Helium-3 proportional counters. The talk will focus on the physics capabilities of the detector; aspects of its design; and its current status.

Speaker: Clarence Virtue (Laurentian University / SNOLAB)

HALO-1kT_CNNP2020.pdf

18:00 → 19:00 SAINTS Poster Session

Tuesday, 25 February

08:30 → 10:30 Invited Talks

Convener: Chair: Kai Zuber (Technical University Dresden)

08:30 Hunting Down Solar Neutrinos; an Extraordinary South African Particle Physics Safari.

The detection of the neutrino and subsequently the solar neutrino had stood for over 25 years as a major challenge for nuclear physicists. The presentation is a narrative of the ground-breaking experiment of the joint South African and American teams of JPF Sellschop and F. Reines for the search of cosmic ray neutrino in the early sixties. The Case Western-Wits team operated a gigantic for its time liquid scintillator detector at an unbelievable depth of almost 3,5 Km undergound in the East Rand Proprietary Gold Mine (EPRM) in Johannesburg. After six years of preparations and operation the first evidence of high-energy cosmic ray neutrino interactions was published in 1965 in Physical Review Letters. This achievement was the determining factor for the career of JPF Sellschop and in certain respects for the development of Nuclear Physics in South Africa.

Speaker: Elias Sideras-Haddad (WITS UNIVERSITY)

ELIAS-HADDAD_CNNP2020.pdf

09:00 First results from the neutrino mass experiment KATRIN

Since the discovery of neutrino oscillation we know that neutrinos have non-zero masses, but we still do not know the absolute neutrino mass scale, which is as important for cosmology as for particle physics. The direct search for a non-zero neutrino mass from endpoint spectra of weak decays is complementary to the search for neutrinoless double beta-decay and analyses of cosmological data.
Today the most stringent direct limits on the neutrino mass originate from investigations of the electron energy spectra of tritium beta-decay.

The next generation experiment KATRIN, the Karlsruhe Tritium Neutrino experiment, is improving the sensitivity from the tritium beta decay experiments at Mainz and Troitsk of 2 eV by one order of magnitude probing the region relevant for structure formation in the universe. KATRIN uses a strong windowless gaseous molecular tritium source combined with a huge MAC-E-Filter as electron spectrometer. To achieve the sensitivity, KATRIN has been putting many technologies at their limits. The full 70m long setup has been successfully commissioned. From early 2019 on KATRIN is taking high statistics tritium data hunting for the neutrino mass.

In this talk a detailed presentation of the KATRIN experiment and its results from the first KATRIN science run will be given. The new results are already bringing KATRIN into the lead position of the field. In the outlook the perspectives of KATRIN for the coming years and new technologies to potentially improve further the sensitivity on the neutino mass will be presented.

Speaker: Christian Weinheimer (Institut für Kernphysik, University of Münster, Germany)

weinheimer_cnnp2020.pdf

09:30 Precision mass measurements for nuclear and neutrino physics studies

Rapidly developing neutrino physics has found in Penning-trap mass spectrometry a staunch ally in investigating and contributing to a variety of fundamental problems. The most familiar are the absolute neutrino mass and the possible existence of resonant neutrinoless double-electron capture / double-beta dacay and of keV-sterile neutrinos. This review provides an overview on the latest achievements and future perspectives of Penning-trap mass spectrometry on short-lived as well as stable nuclides with applications in nuclear structure, neutrino physics and most recently even in dark matter searches where relative mass uncertainties at the level of 10-11 and below are required.

Speaker: Klaus Blaum (Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany )

CNNP_Blaum_Web_2020.pdf

10:00 The Electron Capture in $^{163}$Ho experiment, ECHo

The goal of the Electron Capture in $^{163}$Ho (ECHo) experiment is the determination of the electron neutrino mass by the analysis of the electron capture spectrum of $^{163}$Ho. The detector technology is based on metallic magnetic calorimeters operated at a temperature of about 10 mK in a reduced background environment. For the first phase of the experiment, ECHo-1k, the detector production has been optimized and the implantation process of high purity $^{163}$Ho source in large detector arrays has been refined. The implanted detectors have been successfully operated and characterized at low temperatures, reaching an energy resolution below 5 eV. High statistics and high resolution $^{163}$Ho spectra have been acquired and analyzed in the light of the recent advanced theoretical description of the spectral shape, considering the independently determined and more precise value of the energy available to the electron capture process, $Q_{\rm EC}$. We present preliminary results obtained in ECHo-1k so far and discuss the necessary upgrades towards the second phase of the experiment, ECHo-100k.

Speaker: Christian Enss for the ECHo Collaboration (Kirchhoff Institute for Physics)

ECHo_CNNP.pdf

10:30 → 11:00 Coffee/Tea Break

11:00 → 13:00 Invited Talks

Convener: Chair: Karlheinz Langanke (GSI Darmstadt)

11:00 Probing Dark Energy with the SKA in Africa

I will survey the progress towards the SKA radio telescope array, including the successful building and operation of South Africa's MeerKAT array. Then I will focus on how these instruments can deliver new measurements and insights about the Dark Energy that is driving the accelerated expansion of the Universe.

Speaker: Roy Maartens (University of the Western Cape)

Maartens-SKA-25Feb.pdf

11:30 Dark Matter Direct Detection with Noble Liquids

What is the Dark Matter which makes 85% of the matter in the Universe? We have been asking this question for many decades and used a variety of experimental approaches to address it, with detectors on Earth and in space. Yet, the nature of Dark Matter remains a mystery. An answer to this fundamental question will likely come from ongoing and future searches with accelerators, indirect and direct detection. Detection of a Dark Matter signal in an ultra-low background terrestrial detector will provide the most direct evidence of its existence and will represent a ground-breaking discovery in physics and cosmology. I will review direct detection experiments using noble liquids which have shown the highest sensitivity to-date.

Speaker: Elena Aprile (Columbia University)

12:00 Annual modulation with DAMA/LIBRA-phase2

Abstract: The new results obtained by the first 6 independent annual cycles of DAMA/LIBRA–phase2 experiment deep underground at Gran Sasso are presented; they correspond to a total exposure of 1.13 ton × yr. The improved experimental configuration with respect to the phase1 allowed a lower energy threshold. The DAMA/LIBRA–phase2 data confirm the evidence of a signal that meets all the requirements of the model independent Dark Matter annual modulation signature, at high C.L. The model independent DM annual modulation result is compatible with a wide set of DM candidates. In this talk we summarize some of them and perspectives for the future will be outlined.

Speaker: Pierluigi Belli (INFN Roma Tor Vergata)

belli_CNNP2020.pdf

12:30 COSINE experiment - A WIMP dark matter search experiment with NaI(Tl) detectors

The COSINE experiment searches for interactions of Weakly Interacting Massive Particles (WIMPs) using an array of NaI(Tl) crystal detectors in the 700-m-deep Yangyang underground laboratory, Korea. The main goal is to check the annual modulation signal observed by DAMA/LIBRA with the same target material. The first phase of the experiment, COSINE-100 with 106 kg of NaI(Tl) crystals, has been running stably for more than 3 years. Several analyses in addition to the annual modulation have been actively ongoing, based on the 1 keV energy threshold and about 3 counts/day/kg/keV background rate in an energy region between 1 and 6 keV. In this talk, the detector performance, recent analysis results, and future prospects of the COSINE experiment will be presented.

Speaker: Yeongduk Kim (Institute for Basic Science)

cnnp-ydkim-v2.pdf

13:00 → 14:00 Lunch

14:00 → 16:00 Contributed Talks

Conveners: Main Venue Chair: Klaus Blaum (Max-Planck-Institut für Kernphysik) , Parallel Venue Chair: Giorgio Gratta (Stanford University)

14:00 Borexino solar neutrino data as a probe of non-standard neutrino properties

Neutrinos produced in the Sun can be used as a probe of neutrino physics beyond the Standard Model (BSM). In this study, two BSM processes are considered, namely, non-standard neutrino-electron interactions, and electromagnetic neutrino interaction caused by an anomalous magnetic moment. These processes may occur during both neutrino propagation through the solar matter and detection, causing distortions in solar neutrino fluxes, survival probability, interaction cross sections and other properties. In the Borexino experiment, possible impacts of the non-standard interactions of solar neutrinos to the data have been estimated using both interaction rate and spectral information. For the anomalous neutrino magnetic moment study, both neutrino and anti-neutrino datasets have been considered.

Speaker: Alina Vishneva (JINR)

Alina-NSI_CNNP2020.pdf

14:00 Sensitivity to the neutrinoless double beta decay of the DARWIN observatory

The DARWIN observatory is a proposed next-generation experiment whose primary goal is to search for particle dark matter. It will operate 50 tonnes of natural xenon in a dual-phase time projection chamber under ultra-low background conditions. These two characteristics make DARWIN sensitive to other rare interactions, like the neutrinoless double beta decay of the isotope Xe136. Without isotopic enrichment DARWIN will contain in total more than 4.5t of Xe136. We present here the expected half-life sensitivity for this rare decay. This sensitivity is based on a detailed study of attainable backgrounds, Monte Carlo predictions and event topologies in the homogeneous target. We show that DARWIN will be comparable in its science reach to dedicated double beta decay experiments using enriched Xe136.

Speaker: Patricia Sanchez-Lucas (University of Zurich)

CNNP2020_PatriciaSanchez.pdf

14:20 BBN, Underground Nuclear Astrophysics and Neutrinos

Nuclear astrophysics plays an important role in understanding open issues of neutrino physics. As an example, the two key reactions of the solar p-p chain $^3He(^3He,2p)^4He$ and $^3He(^4He,\gamma)^7Be$ were studied at low energy with LUNA (Laboratory for Underground Nuclear Astrophysics), providing an accurate experimental footing for the Standard Solar Model and consequently to study the neutrino mixing parameters.
The LUNA collaboration has now completed the measurement of the $D(p,\gamma)^3He$ cross section with unprecedented precision at Big Bang Nucleosynthesis (BBN) energies. The accurate study of this deuterium-burning process provides a precise determination of the universal baryon density $\Omega_b$, in agreement with the value derived from CMB data and with comparable accuracy.
Finally, our analysis severely constrains the possible existence of "dark radiation", i.e. the existence of relativistic particles not foreseen in the standard model, such as sterile neutrinos or hot axions [1]. The LUNA result and consequences in cosmology and particle physics are discussed in this contribution.

[1] E. Di Valentino, C. Gustavino et al., Phys. Rev. D 90, 023543 (2014).

Speaker: Carlo Gustavino (INFN-Roma)

Gustavino_CNNP2020.pdf

14:20 The CROSS experiment: rejecting surface events with PSD

Neutrinoless double-beta decay is a hypothetical rare nuclear transition (T^1/2>1026 y). Its observation would provide an important insight about the nature of neutrinos (Dirac or Majorana particle) demonstrating that the lepton number is not conserved. This decay can be investigated with bolometers embedding the double beta decay isotope, the possibility to investigate this rare process is strongly influenced by the background level in the region of interest. A new R&D has recently begun within the CROSS project (Cryogenic Rare-event Observatory with Surface Sensitivity) aiming at the development of bolometric detectors, embedding the promising isotopes 100Mo and 130Te, capable of discriminating surface alpha and beta interactions by exploiting the properties of superconducting material (Al film) or normal metal (Pd film) deposited on the crystal faces (Li2MoO4 and TeO2). These films work as pulse-shape modifiers. The results of the tests on prototypes performed at CSNSM (Orsay, France) showed the capability of a few-µm (nm)-thick Al (Pd) film deposited on the crystal surface to discriminate surface from bulk events, with the required rejection level of the surface background. While Al film can only identify surface alpha particles, there are preliminary indications that normal-metal films can separate also the beta surface component. This is a breakthrough in bolometric technology for double beta decay that could lead to reach a background index in the range 10^-5 counts/(keV kg y). The CROSS cryostat has been recently installed underground (Canfranc, Spain). We plan to run the first CROSS demonstrator in 2021 with 32 enriched Li2100MoO4 crystals containing ~5 kg of 100Mo. A 5-year sensitivity to the effective Majorana neutrino mass mββ with a background of the order of 10^-3 counts /(keV kg y) would be in the range 68-122 meV (2.8 × 10^25 y), at the level of the best currently running experiments.

Speaker: Hawraa Khalife (CSNSM-cnrs (orsay, France))

CNNP2020_v3.pdf

14:40 127I(nu,e)127Xe reaction for solar neutrino spectrum clarification

Solar neutrino spectrum measurement plays a crucial role for solar metallicity determination. 127I(nu,e)127Xe reaction is sensitive to CNO and boron components of the solar neutrino spectrum due to the relatively high threshold (662 KeV).
For neutrinos with energies upper S_n = 7.246 MeV 127I(nu,e) capture produces 126Xe + n. The concentration ratio of 127Xe and 126Xe could clarify parameters of high energy solar neutrino spectrum and neutrino oscillations. We present production rate estimation for of 127Xe and 126Xe based on experimental strength function from 127I(p,n)Xe reaction.

Speaker: Almaz Fazliakhmetov (MIPT)

Fazliakhmetov_CNNP2020.pdf

14:40 Prospects for pair-transfer reactions at iThemba LABS

Pair-transfer reactions such as (p,t) and (³He,n) have been used to probe the pairing in nuclei. The nature of pairing in neutrinoless double-beta decay candidates can strongly impact the predicted nuclear matrix elements linking the ground states of the parent and daughter nuclei in neutrinoless double-beta decay candidates, with various different theoretical approaches such as the QRPA sometimes using the BCS pairing approximation. Evidence from pair-transfer reactions provides evidence for the breaking down of the BCS approximation in some nuclei.

This contribution will discuss experimental developments at iThemba LABS using the K600 magnetic spectrometer to measure (p,t) cross sections, and arrays of HPGe and neutron detectors to measure the (³He,n) reaction, providing an excellent opportunity to probe the nature of pairing in nuclei, including neutrinoless double-beta decay candidates.

Speaker: Philip Adsley (iThemba LABS/Wits)

CNNP2020PAdsley.pdf

15:00 EARTH, a meeting of neutrino- and nuclear- physics.

Over the past 15 years, in the consortium EARTH (Earth AntineutRino TomograpHy), low energy experiments have been carried out with the detection of antineutrinos as a theme. The ultimate goal was to learn more about the role of nuclear decay in the interior of the Earth [1-3]. This required developing direction sensitive antineutrino detection to detect geoneutrinos. Here searching for remnants of possible nuclear reactions may also provide clues [4]. Other experiments were done into whether neutrinos from the Sun have a greater influence on radioactive decay than is commonly accepted by using antineutrinos from reactors as a surrogate to investigate these claims [5]. The work done on these unfinished projects will be reviewed and some ideas for future work will be given.

[1] R.J. de Meijer et al., Earth, Moon and Planets 99 (2006) 193
[2] F.D. Smit et al., PoS (FNDA2006) 096
[3] F.D. Brooks et al., AIP Conference Proceedings 1412, 177 (2011)
[4] R.J. de Meijer et al., Radiation Physics and Chemistry 71 (2004) 769
[5] R.J. de Meijer et al., Applied Radiation and Isotopes 69 (2011) 320

Speaker: Frederick Smit (NRF iThemba LABS, Somerset West, South Africa)

CNNP_EARTH_final.pdf

15:00 Q-value measurements of rare weak beta decays with JYFLTRAP

Rare weak beta decays can be potentially used in searches for the neutrino mass. These are, e.g., decays between nuclear ground states and excited states in daughter nuclei that have very small (< 1 keV) decay energy ($Q$-value). The beta decay of $^{115}$In $9/2^+$ ground state to $3/2^+$ state in $^{115}$Sn currently has the smallest measured $Q$-value (0.155(24) keV [1,2]) of any beta decay.

There are several more nuclei that potentially possess similarly low $Q$-values [3]. Those are optimal for experimental neutrino mass determination through distortions in the beta endpoint spectrum. First, before any attempt to measure the endpoint spectrum, it is necessary to confirm whether the $Q$-value of the decay is positive. The ground-state-to-ground state $Q$-value can be measured with mass spectrometry while the excitation energy of the excited state in the daughter can be deduced from gamma-ray spectroscopy.
Using the JYFLTRAP Penning trap setup [4,5] at the Accelerator Laboratory of the University of Jyväskylä, we have measured $Q$-values of several such cases. One of those is the $^{135}$Cs decay to $^{135}$Ba, which was measured with a precision at the 100-eV level. Along with this Q-value measurement I’ll give an overview of the used Phase-Imaging Ion-Cyclotron mass measurement technique [6].

[1] B.J. Mount, M. Redshaw, E.G. Myers, Phys. Rev. Lett. 103, 122502 (2009).
[2] J. S. E. Wieslander, J. Suhonen, T. Eronen et al., Phys. Rev. Lett. 103, 122501 (2009).
[3] H. Ejiri, J. Suhonen, K. Zuber, Phys. Rep. 797, 1-102 (2019).
[4] T. Eronen et al., Eur. Phys. J. A 48, 46 (2012).
[5] D. Nesterenko et al., Eur. Phys. J. A 54, 154 (2018).
[6] S. Eliseev et al., Appl. Phys. B 114, 107 (2014).

Speaker: Tommi Eronen (University of Jyväskylä)

CNNP2020_Eronen_shortened.pdf

15:20 GERDA Highlights: Probing the Majorana Neutrino Mass at 100 meV

Since 2010, the GERDA project has been operated at Laboratori Nazionali del Gran Sasso (LNGS), searching for the neutrinoless double beta decay (0νββ) of Ge-76 to Se-76. GERDA is nowadays completing its mission, having attained 100 kgy exposure and, as first experiment, surpassed the goal sensitivity of 10^26 yr on the half-life of the searched process. Since its beginning in 2010 GERDA has increased its sensitivity for the measurement of the decay by almost a factor of 5, thanks to excellent passive shield setup, operating procedures, energy resolution, and implementation of active background suppression strategies. The GERDA results allow to directly probe the Majorana neutrino mass down to about 100 meV scale.
In this talk, the GERDA setup, technological features and operation will be summarized, and the above outlined results, based on an exposure of about 85 kgy, will be reviewed in the framework of results from other 0νββ players. The Ge-76 two neutrino double beta decay half-life measured by GERDA, the main detected background sources, the performances and background indexes for the different detector types, the data analysis flow and algorithms will be discussed as well.
The perspectives of the final GERDA data release and the transition to the LEGEND project will be addressed.

Speaker: Luciano Pandola (INFN - Laboratori Nazionali del Sud)

Pandola-GERDA.pdf

15:20 NEON - Neutrino Elastic-scattering Observation with NaI(Tl)

NEON is a proposed experiment to detect coherent elastic neutrino-nucleus scattering (CENNS) with high light yield NaI(Tl) detectors and a reactor as antinuetrino source. Due to extremely low energy signal predicted from the CENNS process, one needs to develop extremely low threshold detectors. We have optimized size of the crystals and developed new optical coupling design for high light collection efficiency. With current best crystal of approximately 23 photoelectrons per keV, a sub-keV scintillation signal is accessible with the NaI(Tl) crystals. We consider to install approximately 10~kg target mass at Hanbit reactor power plant, which is same place of the NEOS short baseline neutrino experiment, in early 2020. The site is 24 m far from reactor core with measured antineutrino flux of 7$\times$10$^{-12}$/cm$^2$/s. We will present current status of detector developments as well as our strategy for an observation of CENNS process with the reactor antineutrino.

Speaker: Hyun Su Lee (Institute for Basic Science)

CNNP2020_HSLee.pdf

15:40 COHERENT’s Neutrino-Induced Neutron Detectors

Neutrino-nucleus interactions can produce excited nuclear states that can de-excite by emitting particles, including neutrons. Neutrino-induced neutrons (NINs) produced in common gamma shielding material, such as lead or iron, can pose a background for neutrino and dark matter experiments. Additionally, NIN production in lead is the primary mechanism for the Helium and Lead Observatory (HALO) to detect supernova neutrinos, and iron-based supernova NIN detectors have been proposed. As part of the COHERENT experiment, two detectors seeking to study NIN production in lead and iron have been deployed to the Spallation Neutron Source (SNS). An overview of the detector design and current status will be presented.

Speaker: Samuel Hedges (Duke University)

20200225_CNNP_SHedges.pdf

15:40 Update on the HOLMES experiment to directly measure the neutrino mass

The absolute neutrino mass is still a missing parameter in the modern landscape of particle physics. The HOLMES experiment aims at exploiting the calorimetric approach to directly measure the neutrino mass through the kinematic measurement of the decay products of the weakly-mediated decay of 163Ho. This low energy decaying isotope, in fact, undergoes electron capture emitting a neutrino and leaving its daughter nucleus, 163Dy*, in an atomic excited state. This, in turn, relaxes by emitting electrons and, to a considerably lesser extent, photons. The high energy portion of the calorimetric spectrum of this decay is affected by the non-vanishing neutrino mass value. Given the small fraction of events falling in the region of interest, to achieve a high experimental sensitivity on the neutrino mass it is important to have a high activity combined with a very small undetected pile-up contribution. To achieve these targets, the final configuration of HOLMES foresees the deployment of a large number of 163Ho ion-implanted TESs characterized by an ambitiously high activity of 300 Hz each. This contribution will provide an overview on the status of the major tasks that will bring HOLMES to achieve a statistical sensitivity on the neutrino mass as low as 2 eV: from the isotope production and embedding to the detector production and readout.

Speaker: Marco Faverzani

faverzani.pdf

16:00 → 16:30 Coffee/Tea Break

16:30 → 17:30 Invited Talks

Convener: Chair: Clarence Virtue (Laurentian University / SNOLAB)

16:30 A high precision narrow-band neutrino beam: the ENUBET project

The knowledge of initial flux, energy and flavor of current neutrino beams is currently the main limitation for a precise measurement of neutrino cross sections. The ENUBET ERC project (2016-2021) is studying a facility based on a narrow band neutrino beam capable of constraining the neutrino fluxes normalization through the monitoring of the associated charged leptons in an instrumented decay tunnel. Since March 2019, ENUBET is also a CERN Neutrino Platform project (NP06/ENUBET) developed in collaboration with CERN A&T and CERN-EN. In ENUBET, the identification of large-angle positrons from $K_{e3}$ decays at single particle level can potentially reduce the $\nu_e$ flux uncertainty at the level of 1%. This setup would allow for an unprecedented measurement of the $\nu_e$ cross section at the GeV scale. Such an experimental input would be highly beneficial to reduce the budget of systematic uncertainties in the next long baseline oscillation projects (i.e HyperK-DUNE). Furthermore, in narrow-band beams, the transverse position of the neutrino interaction at the detector can be exploited to determine a priori with significant precision the neutrino energy spectrum without relying on the final state reconstruction.

This contribution will present the final design of the ENUBET demonstrator, which has been selected on April 2019 on the basis of the results of the 2016-2018 testbeams. It will also discuss advances in the design and simulation of the hadronic beam line. Special emphasis will be given to a static focusing system of secondary mesons that, unlike the other studied horn-based solution, can be coupled to a slow extraction proton scheme. The consequent reduction of particle rates and pile-up effects makes the determination of the $\nu_{\mu}$ flux through a direct monitoring of muons after the hadron dump viable, and paves the way to a time-tagged neutrino beam. Time-coincidences among the lepton at the source and the neutrino at the detector would enable an unprecedented purity and the possibility to reconstruct the neutrino kinematics at source on an event by event basis. We will also present the performance of positron tagger prototypes tested at CERN beamlines, a full simulation of the positron reconstruction chain and the expected physics reach of ENUBET.

Speaker: Andrea Longhin

ENUBET_Longhin_CNNP2020_v5.pdf

17:00 LiquidO detector development

In this talk I will present a potentially game-changing new particle detector technology called LiquidO. This idea turns the concept behind the widespread scintillator detectors on its head: for 50 years research has focussed on making more and more transparent scintillator materials, whereas LiquidO actually requires an opaque scintillator. In LiquidO, scintillation light is confined near its creation point due to a short scattering length and collected by a dense grid of wavelength shifting fibres. The resulting topological information, normally lost in transparent LS detectors, allows for powerful event-by-event particle identification including MeV-scale positrons, electrons and gammas, enabling strong background suppression. Another advantage over classical liquid scintillator detectors is the possibility of loading to unprecedented levels, since high transparency is no longer required. I will give an overview of the LiquidO idea in this talk as well as show the first results from the ’micro-LiquidO’ prototype detector, which provided the proof of principle of light confinement.

Speaker: Jeff Hartnell

Hartnell-cnnp2020.pdf

Wednesday, 26 February

08:30 → 10:30 Invited Talks

Convener: Chair: Christian Enss (Heidelberg University)

08:30 Roles of Neutrinos in Explosive Nucleosynthesis of Supernovae and Neutron-Star Mergers and Cosmic Evolution

The big-bang universe, supernovae (SNe), collapsars and binary neutron-star mergers (NSMs) are the viable celestial sources of “multi-messengers”. These messengers are neutrinos for weak force, gravitational waves for gravity, photons for electromagnetism, and atomic nuclei for strong nuclear force [1]. Their detection takes the keys to solve still unanswered questions such as mass hierarchy of neutrinos [2], overproduction of big-bang lithium [3], the origin of p-nuclei [4], and the origin of r-process elements [1,5]. We will discuss the roles of neutrinos and radioactive nuclei for solving these problems.
Still unknown neutrino mass and oscillations are particularly important to answer the fundamental question why we need to go beyond the standard theory of elementary particles and fields. We will, first, discuss cosmological background neutrinos and fluctuations of primordial magnetic fields in order to solve overproduction problem of primordial big-bang lithium [3]. The relic SN neutrinos also are the energetic component of cosmic background neutrinos. We will propose a method how to constrain the neutrino mass hierarchy and EOS of proto-neutron stars in the proposed HK project of detecting these energetic neutrinos [6].
A huge flux of neutrinos is emitted from proto-neutron stars or accretion disks formed in SNe, collapsars and binary NSMs. The collective flavor oscillation due to the neutrino self-interactions is presumed to occur in the deepest region inside the iron-core, while the MSW high-density resonance occurs near the bottom of He/C-layer. The light mass nuclei, 7Li and 11B, and the intermediate-to-heavy mass nuclei, 19F, 50V, 53Mn, 92Nb, 98Tc, 138La and 180Ta, are respectively produced in outer He/C-layer and inner O-Ne-Mg-layer exposed to the intense neutrino flux (-process) [2]. The intermediate mass p-nuclei, 74Se, 78Kr, 84Sr, 74Se, 92,94Mo and 96,98Ru (p-process) [4], and r-process nuclei [1] are produced in the iron-core. Therefore, nucleosynthesis of 7Li and 11B is affected by both collective and MSW effects, however all the other intermediate-to-heavy mass nuclei are affected by the collective oscillation alone, being almost free from MSW effect. We will, secondly, discuss how differently these nucleosynthetic products depend on each of collective or MSW neutrino oscillation effect, and will propose how to distinguish these two effects from each other [2].
Finally, we will discuss the origin of r-process nucleosynthesis to understand the cosmic evolutionary history of each contribution from SN, collapsar and binary NSM [5]. We here discuss the roles of GW detection and spectroscopic astronomical observation of atomic nuclei as well as nuclear experiments of radioactive nuclei [1].

Speaker: Taka Kajino (Being University/NAOJ/University of Tokyo)

09:00 First-forbidden transitions in the reactor antineutrino ux and spectral anomalies

It has been almost a decade since the reactor antineutrino anomaly entered the stage, where the number of experimentally detected antineutrinos emerging from a nuclear power reactor interior was signi?cantly less than theoretically predicted from nuclear ? decay. This has, in turn, motivated the search for an eV-scale sterile neutrino in several very short baseline experiments, none of which have so far confi?rmed its existence. From the theory point of view, initial analyses introduced a signi?cant number of approximations, in particular for the treatment of so-called forbidden transitions. We report on the first large-scale calculation of the influence of ?first-forbidden ?transitions using state-of-the-art nuclear shell model calculations for a select number of highly-contributing ? branches. We use these results to propose a probability distribution for ?first-forbidden spectral shapes and employ Monte Carlo techniques to translate this into a detailed construction of theoretical uncertainties for the remaining forbidden transitions. We observed signi?cant changes in both the integrated
ux and spectral shape of the cumulative antineutrino spectra spectra for all ?ssion actinides [1, 2], and discuss both a mitigation of the so-called reactor shoulder and changes in the reactor antineutrino anomaly. Finally, we will comment how an improved treatment of allowed ? transitions [2, 3] can further signi?cantly change both ux and spectral shape.
[1] L. Hayen, J. Kostensalo, N. Severijns, and J. Suhonen, Physical Review C 99, 031301(R) (2019).
[2] L. Hayen, J. Kostensalo, N. Severijns, and J. Suhonen, Physical Review C 100, 054323 (2019), arXiv:1805.12259.
[3] L. Hayen, N. Severijns, K. Bodek, D. Rozpedzik, and X. Mougeot, Reviews of Modern Physics 90, 015008 (2018),
arXiv:1709.07530.

Speaker: Leendert Hayen (North Carolina State University & Triangle Universities Nuclear Laboratory)

CNNP2020_26_2_2020 (1).pdf

09:30 The CONUS Experiment and future potential of coherent neutrino scattering

Coherent elastic neutrino nucleus scattering (CEvNS) was first observed 2018 with neutrinos from pion decay at rest. CONUS aims at detecting CEvNS with low energy anti-neutrinos. It uses novel Germanium detector technology and a virtual depth shield for operation at shallow depth only 17 meters away from the core of a multi GW power reactor. The talk will cover the status of CONUS, latest results and an outlook of the potential of future CEvNS experiments.

Speaker: Manfred Lindner (Max-Planck-Institut für Kernphysik)

Lindner.pdf

10:00 What we can learn from CEvNS? (CEvNS - Coherent Elastic Neutrino Nucleus Scattering)

CEvNS process has been predicted in 1974 right after discovery of the neutral current of the week interactions. It took more than 40 years to confirm this prediction experimentally. In 2017 COHERENT collaboration reported of the first observation of CEvNS using 14 kg CsI detector and SNS neutrino source at the ORNL. In my talk I will review first observation of CEvNS and present experimental status to study CEvNS. The focus of my talk will be how we can use accurate CEvNS measurements to test S-M of the particle physics, and make contribution into nuclei physics and astrophysics.

Speaker: Yuri Efremenko (University of Tennessee, USA)

Efremenko_Slides.pdf

10:30 → 11:00 Coffee/Tea Break

11:00 → 13:00 Invited Talks

Convener: Chair: Horst Lenske (U. Giessen)

11:00 Majorana neutrino mass generation, $0\nu\beta\beta$-decay and nuclear matrix elements

: A Quark Condensate See-Saw (QCSS) mechanism of generation of Majorana neutrino mass due to spontaneous breaking of chiral symmetry accompanied with the formation of a quark condensate is presented. Consequencies of this scenario of neutrino mass generation for the neutrinoless double beta decay ($0\nu\beta\beta$-decay), tritium beta decay and cosmological measurements are drawn. The attention is paid also to the problem of reliable calculation of the $0\nu\beta\beta$-decay nuclear matrix elements and the evaluation of quenching of the axial-vector coupling constant $g_A$.
For solving of these nuclear physics problems an importance of experimental study of the two-neutrino double-beta decay, muon capture in nuclei and nuclear charge-exchange reactions is stressed.

Speaker: Fedor Simkovic (Comenius University)

FSimkovic_CNNP_2020.pdf

11:30 Nuclear Matrix Elements of neutrinoless double beta decay calculated by Monte Carlo Shell Model for 76Ge and 136Xe

The neutrinoless double beta decay is of special importance in determining the fundamental properties of neutrinos. The nuclear matrix element of this decay must be evaluated in a sufficient accuracy, and the shell-model calculation can make contributions to this end. This is because the shell-model calculations incorporate basically all correlations into the wave functions of the initial and final states of the decay, and the accuracy of the calculation can be investigated by referring to other observables. I will report results obtained by recent large-scale shell-model calculations on 76Ge and 136Xe as well as their daughter nuclei 76Se and 136Ba. Here the large-scale shell-model calculations mean those by Monte Carlo Shell Model at its most advanced edition. The results are not away from the ranges of earlier studies, but are rather on the edges of smaller values. I will also discuss why such smaller values arise as natural consequences of basic features of the wave functions.

Speaker: Takaharu Otsuka (Department of Physics, University of Tokyo)

12:00 Ab initio nuclear theory for beyond standard model physics

Long considered a phenomenological field, breakthroughs in many-body methods together with our treatment of nuclear and electroweak forces are rapidly transforming modern nuclear theory into a true first- principles, or ab initio, discipline. In this talk I will discuss recent advances, which expand the scope of ab initio theory to global calculations of nuclei, potentially as heavy as 208Pb, including first predictions of the limits of nuclear existence into the medium-mass region.
I will then focus on recent extensions to fundamental problems in nuclear-weak physics, including a proposed solution of the long-standing gA quenching puzzle, calculations of neutrinoless double-beta decay for determining neutrino masses, and WIMP-nucleus scattering cross sections relevant for dark matter direct detection searches.

Speaker: Jason Holt (TRIUMF)

Holt_CNNP2020.pdf

12:30 Theory of Double-Beta Decay from First Principles

I discuss recent work to calculate the nuclear matrix elements that govern neutrinoless double beta decay in an ab-initio way, that is, without the adjustment of parameters except those in chiral effective field theory. A method based on the use of techniques from energy-density functional theory in combination with ab-initio Hamiltonians has proved particularly powerful. I describe its application to the double-beta matrix elements of 48Ca and 76Ge.

Speaker: Jonathan Engel

Engel-cnnp2020.pdf

13:00 → 14:00 Lunch

14:00 → 18:00 Excursion

Thursday, 27 February

08:30 → 10:00 Invited Talks

Convener: Chair: Manfred Lindner (Max-Planck-Institut für Kernphysik)

08:30 Neutrinos in DUNE: long-baseline oscillations and non-beam physics

The Deep Underground Neutrino Experiment (DUNE) is one of the most ambitious particle physics experiments of the next generation. DUNE consists of two detectors: the Near Detector (ND) - just downstream of the neutrino beam at FERMILAB (IL - USA), and the Far Detector (FD) - 1300 km away and 1500 m deep in the underground SURF laboratory (SD - USA). The ND is a multi-technology apparatus aiming to constrain the uncertainties related to the unoscillated neutrino flux and also to explore neutrino interactions physics. The FD is a modular 40 kton fiducial mass Liquid Argon Time Projection Chamber, dedicated to studying long-baseline neutrino oscillations, which includes precise measurements of neutrino mixing parameters, the CP violation phase as well as the determination of neutrino mass hierarchy. The physics list of DUNE extends to non-beam physics like supernova neutrinos and search for nucleon decay. In this contribution, we describe the main features of DUNE and its sensitivity for measurements on the primary physics goals.

Speaker: Ernesto Kemp (University of Campinas - UNICAMP)

Kemp_Slides.pdf

09:00 Status of the T2K experiment

Current status of the T2K long-baseline neutrino-oscillation experiment is presented.
Future upgrades and prospects in coming ten years are also reported.

Speaker: Yuichi Oyama (KEK/J-PARC)

cnnp2020.t2k.oyama.pdf

09:30 Neutrino masses, mixings and electroweak nuclear physics

The current status of the mass-mixing parameters in the three-neutrino framework will be reviewed. The increasing connections between neutrino and nuclear physics will be highlighted. A case will be made for establishing an interdisciplinary field, that might be named as "electroweak nuclear physics".

Speaker: Eligio Lisi (INFN, Bari, Italy)

Lisi_CNNP2020_reduced.pdf

10:00 → 10:30 Coffee/Tea Break

10:30 → 12:30 Invited Talks

Convener: Chair: Jouni Suhonen (University of Jyväskylä)

10:30 Benchmarking aspects of weak interaction physics via precision beta decay spectroscopy and two-nucleon transfer reactions

In this talk I shall present results from recent high-precision half-life and branching ratio measurements for 19Ne beta decay and the detailed spectroscopic analyses of states in 136Ba and 136Cs via two-nucleon transfer reactions. I will briefly discuss the connection between these experiments in the context of Standard Model tests, highlighting the importance of reconciling the experimental results with state-of-the-art theory calculations. Particular emphasis will be placed on implications pertaining to neutrinoless double beta decays.

Speaker: Smarajit Triambak (University of Western Cape)

triambak_CNNP.pdf

11:00 Recent results on nuclear reactions of interest for neutrinoless double beta decay at INFN-LNS within the NUMEN project

Researches on neutrinoless double beta decay have crucial implications on particle physics, cosmology and fundamental physics. It is likely the most promising process to access the absolute neutrino mass scale. To determine quantitative information from the possible measurement of the 0νββ decay half-lives, the knowledge of the Nuclear Matrix Elements (NME) involved in such transitions is mandatory. The use heavy-ion induced double charge exchange (DCE) reactions as tools towards the determination of information on the NME is one of the goals of the NUMEN and the NURE projects. The basic point is that there are a number of similarities between the two processes, mainly that the initial and final state wave functions are the same and the transition operators are similar, including in both cases a superposition of Fermi, Gamow-Teller and rank-two tensor components.
The availability of the MAGNEX magnetic spectrometer for the measurements of the very suppressed DCE reaction channels is essential to obtain high resolution energy spectra and accurate cross sections at forward angles including zero degree. The measurement of the competing multi-nucleon transfer processes allows to study their contribution and to constrain the theoretical calculations.
An experimental campaign is ongoing at INFN-Laboratori Nazionali del Sud (Italy) to explore medium-heavy ion induced reactions on target of interest for 0νββ decay.
Recent results obtained by the (20Ne,20O) and (18O,18Ne) DCE reactions and competing channels, measured for the first time using a 20Ne(10+) and 18O(8+) cyclotron beams at 15 AMeV will be presented at the conference. A preliminary analysis of the double charge exchange channel in comparison with the competitive multi-nucleon transfer channels will also be shown and commented.

Speaker: Manuela Cavallaro (INFN - LNS)

Cavallaro_CNNP2020_web.pdf

11:30 Heavy ion charge exchange reactions as probes for nuclear β-decay

The status and prospects of heavy ion charge exchange reactions are discussed. Their important role for nuclear reaction, nuclear structure, and beta-decay investigations is emphasized. Dealing with peripheral reactions, direct reaction theory gives at hand the proper methods for single (SCE) and double charge exchange (DCE) ion–ion scattering. The microscopic descriptions of charge exchange ion–ion residual interactions and the reaction mechanism are obtained by distorted wave theory. Ion–Ion optical potentials and reaction form factors are determined in a folding approach by using NN T-matrices and microscopic ground state and transition densities, respectively. The theory of onestep direct and two-step transfer reaction mechanisms for SCE reactions is discussed and illustrated in applications to data. Specific SCE reactions are discussed in detail, emphasizing the versatility of projectile–target combinations and incident energies. SCE reactions induced by 12C and 7Li beams are presented as representative examples. Heavy ion DCE reactions are shown to proceed in principle either by sequential pair transfer or two kinds of collisional NN processes. Double single charge exchange (DSCE) is given by two consecutive SCE processes, resembling in structure 2ν2β decay. A competing process is a two-nucleon mechanism, relying on short range NN correlations and leading to the correlated exchange of two charged mesons between projectile and target. These Majorana DCE (MDCE) events are of a similar diagrammatic structure as 0ν2β decay. The similarities of the DSCE and MDCE processes to pionic DCE reactions are elucidated. An overview on recent applications to heavy ion DCE data is given.

Speaker: Horst Lenske (U. Giessen)

Lenske_CNNP_2020_publ.pdf

12:00 Status of the Mo-100 based AMoRE neutrinoless double beta decay experiment

The AMoRE (Advanced Mo-based Rare process Experiment) intends to find an evidence for neutrinoless double beta decay of Mo-100 by using a cryogenic technique with molybdate based crystal scintillators. The crystals, which are cooled down to 10~20 mK temperatures, are equipped with MMC-type phonon and photon sensors to detect both thermal and scintillation signals produced by a particle interaction in the crystal to achieve high energy resolution and efficient particle discrimination. The AMoRE-pilot experiment with an array of six 48deplCa100MoO4 crystals with a total mass of about 1.9 kg was performed at the 700-m-deep YangYang underground laboratory and AMoRE-I preparation is in progress with ab ~ 6.1 kg of crystals, mostly 48deplCa100MoO4 and several R&D crystals such as Li2100MoO4 crystals. Significant improvement of effective Majorana neutrino mass sensitivity at the level of inverted hierarchy of neutrino mass, 20-50 meV, could be achieved by the AMoRE-II with 200 kg of molybdate crystals at the new 1,000 m deep underground laboratory excavated by the end of 2021 in the Yemi. Results of the AMoRE-pilot and status of the AMoRE-I and AMoRE-II preparation will be presented.

Speaker: Hong Joo Kim (Kyungpook National University)

12:30 → 13:30 Lunch

13:30 → 14:50 Contributed Talks

Conveners: Main Venue Chair: Yuichi Oyama (KEK/J-PARC) , Parallel Venue Chair: Smarajit Triambak (University of Western Cape)

13:30 Limits on the spectral parameters of core-collapse neutrinos extracted from the Diffuse Supernovae Neutrino Flux (DSNvF).

In February 1987 neutrinos from the SN1987 traveled a distance of about 50 kpc from the Large Magellanic Cloud and were detected on Earth by two of the largest neutrino telescopes of that time, Kamiokande-II and IMB, thus confirming the vast amount of energy (~10^53 ergs) predicted to be emitted in neutrinos and setting allowed intervals for the emission parameters like the neutrinosphere temperature. The confirmation of the main features of neutrino emission for a single supernova also supports the prediction that all the past supernovae in the universe should originate a ubiquitous and isotropic neutrino flux, the so-called Diffuse Supernova Neutrino Flux (DSNvF). Up to now, no evidence of events from DSNvF was found by different neutrino telescopes. In this work, we use the upper limit on the DSNvF obtained from the null results of the Super-Kamiokande collaboration to estimate limits on average energy, spectral pinching, and neutrinosphere temperature for electron antineutrinos from a core-collapse neutrino burst. Finally, we check our results with those obtained from the solely SN1987a data concluding that the DSNvF may lead to comparable - or even better - upper limits on the neutrino emission parameters.

Speaker: Ernesto Kemp (University of Campinas - UNICAMP)

13:30 Tests of three-neutrino paradigm by MINOS and MINOS+ Experiments

MINOS and MINOS+ experiments collected unprecedented amount of data using two long baseline detectors that operated on axis of the NuMI neutrino beam at Fermilab. This has allowed to conduct some of the best measurements of neutrino oscillations that provide stringent constraints on neutrino mixing and transitions involving sterile neutrinos. We will present the latest results from these studies.

Speaker: Karol Lang (University of Texas at Austin)

Lang-MINOS-CNNP-Feb-2020-post.pdf

13:50 Deflection of cosmic neutrino by a stellar magnetic field

Neutrinos in the Standard Model (SM) are considered neutral particles. However, recent experiments showed that the neutrino has infinitesimal electric charge leads to non-zero magnetic moment (μ) with precise constraints on the value, this electromagnetic interaction contribution enhances neutrino properties i.e. Oscillation, Scattering, and Spin. This work discusses the possible neutrino deflection under the influence of Interstellar Magnetic Field (IMF) or at extreme magnetic field condition exists in celestial objects, and for what limit could affect the neutrino flux measured at Earth. The primary results were validated by SN1987A supernovae arrival time data.

Speaker: Mohamed Ismaiel (Helwan University)

13:50 Sterile neutrino searches with the ICARUS detector

The ICARUS collaboration employed the 760-ton T600 detector in a successful three-year physics run at the underground LNGS laboratories studying neutrino oscillations with the CNGS neutrino beam from CERN, and searching for atmospheric neutrino interactions. ICARUS performed a sensitive search for LSND-like anomalous $\nu_e$ appearance in the CNGS beam, which contributed to the constraints on the allowed parameters to a narrow region around 1 eV$^2$, where all the experimental results can be coherently accommodated at 90% C.L. After a significant overhauling at CERN, the T600 detector has now been placed in its experimental hall at Fermilab where installation activities are in progress. It will be soon exposed to the Booster Neutrino Beam to search for a sterile neutrino within the Short Baseline Neutrino (SBN) program, devoted to definitively clarify the open questions of the presently observed neutrino anomalies. The proposed contribution will address ICARUS achievements, its status and plans for the new run at Fermilab and the ongoing developments of the analysis tools needed to fulfill its physics program.

Speaker: Vincenzo Bellini (INFN/Catania)

Bellini-CNNP2020.pdf

14:10 Detection of supernova neutrino signal with NOvA detectors

The NOvA experiment has two segmented liquid scintillation detectors,
which are sensitive to the neutrino signal from a core-collapse
supernova in our galaxy. Each of these detectors performs an online
reconstruction and analysis of the neutrino interaction candidates,
comparing their time distribution to that of the signals expected from a
core-collapse supernova. The statistical significance calculated in
this comparison is used to decide if a detector is currently observing a
supernova signal.

The combination of these significance values from both detectors
provides a more efficient metric for detecting the supernova signal,
increasing the maximum distance at which NOvA can detect a core-collapse
supernova.

NOvA's approach for its combination of two detectors for supernova
detection can be generalized to a network of various detectors with
different background levels and sensitivities.

Speaker: Andrey Sheshukov (Joint Institute for Nuclear Research)

SN_CNNP_27Feb2020.pdf

14:10 Hints of non-unitarity in the present T2K and NO$\nu$A data

The mixing of three neutrino flavours is parameterised by the unitary
PMNS matrix. If there are more than three neutrino flavours, effective $3\times 3$ neutrino mixing
matrix will be non-unitary. In this paper, we have analysed the
latest T2K and NO$\nu$A data with the hypothesis of non-unitary mixing matrix.
Present results from NO$\nu$A and T2K collaboration have tension between them as NO$\nu$A disfavours T2K
best-fit point at $1\, \sigma$ confidence level and vice versa. In this paper we have shown that latest data from both the
experiments disfavour unitary $3\times 3$ mixing at $60\%$ C.L. The combined analysis disfavours unitary mixing
at $1\, \sigma$ C.L. Moreover, the tension between two experiments can also be reduced with the non-unitary approach.

Speaker: Ushak Rahaman (University of Johannesburg)

Rahaman-cnnp2020.pdf

14:30 -

14:30 Status and prospects of the KM3NeT/ORCA

KM3NeT is the next-generation neutrino Cherenkov telescope currently under construction in the Mediterranean Sea. Its low energy configuration ORCA (Oscillations Research with Cosmics in the Abyss) is optimised for the detection of atmospheric neutrinos with energies above ∼1 GeV. The main research target of the ORCA detector is the measurement of the neutrino mass ordering (NMO) and atmospheric neutrino oscillation parameters. This contribution will present the first results on atmospheric neutrinos detected with the already deployed ORCA detection units. The projected sensitivity of the detector to the NMO will be shown, alongside prospects for early analyses of data collected with a small sub-array of the detector during construction phase. The ORCA potential for other physics topics, including dark matter, non-standard interactions, sterile neutrinos, and supernovae neutrino detection will also be presented.

Speaker: Salvador Miranda Palacios (University of Johannesburg)

Salvador_Miranda_Slides.pdf

14:50 → 15:10 Coffee/Tea Break

15:10 → 16:40 Invited Talks

Convener: Chair: Francesca Gulminelli (LPC Caen and University of Caen, France)

15:10 Solar Models and Neutrino: where do we stand?

In this talk, I will present the status of solar models, review the main limitations imposed by uncertain input physics in the models and by external constraints (aka solar abudances), and discuss the current constraints imposed from helioseismic and solar neutrino measurements. Also, I will discuss the implications that our current limitations in modeling the Sun have for stellar physics. Finally, some discussion will be devoted to the importance of a prospective measurement of solar neutrinos from the CN-cycle would have for solar models and other fields.

Speaker: Aldo Serenelli (Institute of Space Sciences (ICE-CSIC))

serenelli_cnnp2020.pdf

15:40 Status and perspectives of the Hyper-Kamiokande project

A future neutrino experiment based in Japan, Hyper-Kamiokande (HK) consists of a high-intensity neutrino beam from the J-PARC accelerator targeting a Near Detector suite, an Intermediate Water Cerenkov detector and an underground world-largest Water Cerenkov Far Detector, providing 0.19 Mt (fiducial mass) of ultra-pure water sensed by newly developed photo-sensors with 40%-equivalent photo-coverage, to perform Cerenkov ring reconstruction with a few MeV energy threshold. A second identical far detector may later be added in Korea.
Building on the legacy of Super-Kamiokande and T2K, the HK project will address a broad scientific program and substantially enhance our knowledge of both particle physics and astrophysics. Its objectives include precise measurements of neutrino oscillations and CP-asymmetry (with CPV discovery at 3 sigma for 76% of the phase space), solar neutrino astronomy, determination of supernova burst dynamics, detection of supernova relic neutrinos allowing to study supernova populations, searching for nucleon decay with improved sensitivity (10^{35} years for p->epi0 mode at 90%CL) and finding possible exotic phenomena.
Here we will present the project status and milestones, from the beginning of construction in 2020 towards the commissioning in 2027.

Speaker: Federico Nova (Rutherford Appleton Laboratory)

2020_02_CNNP2020.pdf

16:10 Results and future perspectives of Borexino

The Borexino liquid scintillator neutrino observatory is devoted to perform high-precision neutrino observations: the study of solar neutrinos is the primary goal of the experiment. The exceptional radiopurity together with the good energy resolution (5% at 1 MeV) put Borexino in the unique situation of being able to validate the MSW-LMA oscillation paradigm across the full solar energy range. A comprehensive study of the pp-chain neutrinos was recently released: this new study reports the direct measurements of pp, 7Be and pep neutrino fluxes with the highest precision ever achieved (down to ~2.8% in the 7Be component), the 8B with the lowest energy threshold, the best limit on CNO neutrinos and the first Borexino limit on hep neutrinos. The present talk shows the new results based on the full 10 years data sample and, in particular, on the more radiopure Phase-2 data, taken after the detector purification campaigns in 2010-11 and the perspectives for the final stage of the solar program. The talk will be concluded reporting the latest news on the detection of geoneutrinos with Borexino and the analysis techniques applied.

Speaker: Alessio Caminata (INFN Genoa)

CNNP2020.pdf

19:00 → 00:00 Conference Dinner with Welcome Address by Dr Clifford Nxomani - NRF Deputy CEO: National Research Infrastructure Platforms

Friday, 28 February

09:00 → 10:20 Contributed Talks

Conveners: Main Venue Chair: Manuela Cavallaro (INFN - LNS) , Parallel Venue Chair: Giovanni Benato (LNGS-INFN)

09:00 Decay Characteristics of the Scissors Mode of 0νββ-Decay Partner Isotopes*

The search for neutrinoless double beta (0νββ) decay, a process only allowed if the neutrino were a Majorana particle, recently gained much attention with numerous experiments being dedicated to its observation. It would demonstrate lepto-genesis in the universe and allow the determination of the neutrino mass from its decay rate. However, to quantitatively extract the neutrino mass or estimate decay rates a nuclear matrix element (NME) is required, which has to be calculated using nuclear structure models. One of them is the Interacting Boson Model 2 (IBM-2), which will be discussed below. Those calculations can be difficult because many of the 0νββ-decay candidate nuclei lie in regions of the nuclear chart that feature shape coexistence, with the hypothesized 0νββ-decay mother nucleus ¹⁵⁰Nd and its daughter ¹⁵⁰Sm even being located in the region of a shape phase transition along their respective isotopic chains. In particular, the occurrence of shape coexistence may lead to a significant population of an excited 0⁺ state in 0νββ decay. To improve 0νββ-NME calculations for ¹⁵⁰Nd and ¹⁵⁰Sm within the IBM-2 information on its so-called Majorana interaction is needed. Therefore, new data on the decay characteristics of the scissors mode of these nuclei was recently taken in nuclear resonance fluorescence experiments performed at the High Intensity γ-ray Source. The decay characteristics of the scissors mode are sensitive to the nuclear deformation and allow inducing constraints on model parameters, especially the Majorana parameters of the IBM-2, in turn resulting in a more reliable prediction of the 0νββ-NME. Similar information has also been obtained for the 0νββ-partner nuclides ⁸²Se and ⁸²Kr. The experimental results and updated IBM-2 calculations will be presented and discussed.
*Supported by the DFG through the research grant SFB 1245 and by the State of Hesse under the grant “Nuclear Photonics” within the LOEWE program.

Speaker: Jörn Kleemann (AG Pietralla Institut für Kernphysik Technische Universität Darmstadt)

CNNP2020_Kleemann.pdf

09:00 The search for eV sterile neutrinos with the STEREO experiment

In the last decade, two unsolved anomalies have appeared from the study of reactor neutrinos: one related to the neutrino spectral shape, and another to the absolute neutrino flux. The second one, known as the Reactor Antineutrino Anomaly, presents a deficit in the observed flux compared to the expected one that could point to the existence of a light sterile neutrino in the eV range participating in the oscillation phenomena.
The STEREO experiment is a short baseline reactor antineutrino experiment trying to test the existence of those sterile neutrinos. This experiment, taking data since the end of 2016, measures the antineutrino energy spectrum from the compact core of the research reactor of the Institut Laue-Langevin (Grenoble, France) operated with highly enriched U-235 fuel. Covering baselines between 9 and 11m with a segmented neutrino target, STEREO can study the rate of neutrino interactions and compare it among cells to test oscillation hypotheses at different distances from the source. STEREO can also measure the absolute neutrino flux and spectral shape emitted from a pure U-235 core.
Neutrino data from 179 (235) days of reactor turned on (off) have been analyzed, showing compatibility with the null oscillation hypothesis and rejecting the best fit point of the Reactor Antineutrino Anomaly at 99.8% C.L. In this talk, these results together with the latest improvements in the description of the detector models and the background treatment are reported, providing a crucial input in the search for sterile neutrinos.

Speaker: Helena Almazan (Max-Planck-Institut fuer Kernphysik)

CNNP2020_HAlmazan.pdf

09:20 GT Nuclear resonances for 71Ga(nu,e)71Ge reaction investigation

Neutrino-matter interaction has great importance for neutrino physics and astrophysics. Neutrino capture cross-section depends on the structure of the target nucleus strength function. 71Ga(v,e)71Ge process could be analysed using the charge-exchange strength functions of 71Ga(p,n)71Ge and 71Ga(3He,t)71Ge reactions. Nuclear phenomenology of charge-exchange reactions describes not only discrete excited levels, but also collective resonant states such as GTR and pygmy-resonances. It is shown that accounting of GT-resonances increase neutrino capture rate and that capture rate is very sensitive to the exact behavior of the Fermi function at low energies. We will discuss the quenching effect estimation and the accuracy of B(GT) extraction from experimental data as a function of resonance width. The talk proposes a comparison of the experimental data processing and calculations obtained in the framework of the self-consistent theory of finite Fermi systems.

Speaker: Grigory Koroteev (Moscow Institute of Physics and Technology)

CNNP_Koroteev_28.02.pdf

09:20 Implications of new theoretical calculations on reactor antineutrino and gallium anomalies

The reactor antineutrino and gallium anomalies have been long unexplained. Possible explanations for both of these anomalies include new physics, such as the existence of one or more eV-scale sterile neutrino [Ga15]. However, the previous theoretical calculations, which do not replicate the experimental results, rely on many simplifying approximations [Ba97,Ha19].

In the reactor-antineutrino analysis the beta decays contributing to the cumulative electron spectrum are usually assumed to have allowed spectral shapes. However, many of these decays are actually first-forbidden. Moreover, these decays dominate the experimentally observable region. In some cases, like in the case of the ground-state-to-ground-state decay of $^{140}\rm Cs$ (see figure), this is found to be a rather poor approximation. Based on the recent results, the use of this allowed approximation can at least partially explain the so called reactor antineurtino anomaly.

Our new large-scale shell model calculations regarding the neutrino-nucleus scattering cross section off $^{71}\rm Ga$ shows no statistical difference to the experimental results of GALLEX and SAGE experiments. Conflict between charge-exchange BGTs and the neutrino-nucleus cross sections can to some extent be explained by destructive interference between Gamow-Teller and tensor contributions. A Bayesian approach to estimating the significance of the gallium anomaly is discussed.

[Ga15] S. Gariazzo, C. Giunti, M. Laveder, Y. F. Li, and
E. M. Zavanin, J. Phys. G: Nucl. Part. Phys. 43, 033001
(2015).

[Ba97] J. N. Bahcall Phys. Rev. C 56, 3391 (1997).

[Ha19] L. Hayen, J. Kostensalo, N. Severijns, and J. Suhonen
Phys. Rev. C 99, 031301(R) (2019).

Speaker: Joel Kostensalo (University of Jyvaskyla, Finland)

Kostensalo-CNNP2020.pdf

09:40 Calculation of the neutrino-nuclear reaction cross-sections for 𝑮𝒆𝟕𝟔 nuclei and estimation of the solar neutrino background in the GERDA/LEGEND experiments.

The work presents calculations of the neutrino-nuclear reaction cross-sections using the
example of the nucleus 𝐺𝑒'( (𝐺𝑒'( 𝜈, 𝑒 𝐴𝑠'( ). In the structure of the nucleus, not only
discrete, but also continuous states formed due to the collective interaction of nucleons were
distinguished. In particular, the contribution of the Giant Gamow-Teller resonance and so-called
pygmy resonances in the capture rate of solar neutrinos was estimated (an increase of 25% to
50%, depending on the quenching parameter used).
Based on the obtained capture rate, a Monte Carlo simulation of the subsequent beta
decay of the nucleus 𝐴𝑠'( (𝐴𝑠'( → 𝑆𝑒'( + 𝑒2 + 𝜈 + 𝑛𝛾) was carried out for germanium
detectors in the GERDA experiment. Thus, the contribution of the background component due
to solar neutrinos was estimated, which, due to the small cross-sections of neutrino-nuclear
reactions, is practically unremovable, imposing confines on the sensitivity limit of the setup.
A similar assessment can be made for the upcoming LEGEND experiment taking into
account its geometry. Preliminary results suggest that BI of solar neutrinos are 1-2 orders of
magnitude lower than the predicted accuracy of the LEGEND experiment.

Speaker: Andrei Vyborov (Moscow Institute of Physics and Technology)

Calculation of the neutrino-nuclear reaction cross-sections for 𝑮𝒆𝟕𝟔 nuclei and estimation of the solar neutrino background in the GERDA:LEGEND experiments .pdf

09:40 Neutrino-induced reactions on $^{13}$C and $^{16}$O at supernova neutrino energies

Neutrino-nucleus reactions on $^{13}$C and $^{16}$O at supernova (SN) energies are investigated by shell-model calculations with the use of new Hamiltonian, which can describe spin responses of nuclei quite well. Cabon-based scintillators and water-Cerenkov scintillators relevent to SN observation and experiments at the spallation neutron sources are now available. Cross sections for various particle and $\gamma$ emission channels are evaluated by the statistical Hauser-Feshbach method.
For $^{13}$C, total reaction cross sections at reactor and solar neutrino energies were studied [1]. Here, we extend our study to SN neutrino energies up to $\approx$50 MeV, and evaluations of partial cross sections for proton and neutron emission channels within the Standard Model [2]. Among them, a reaction channel $^{13}$C ($\bar{\nu}$, $\bar{\nu}$'n) $^{12}$C (2$^{+}$, 4.44 MeV) followed by prompt 4.44 MeV $\gamma$ emission is discussed in relation to the shape distortion in the 5-7 MeV range in the measured neutrino spectrum in the short-baseline reactor neutrino experiments [3]. The cross section is too small to explain the extra enhancement in the spectrum.
Coherent elastic scattering cross section is obtained for ${13}$C, and compared with that for $^{12}$C. Nuclear structure effects in the cross sections are pointed out [2]. Possible merit of large recoil momenta in light nuclei for the study of neutron distributions in nuclei is discussed.
For $^{16}$O, spin-dipole strength, which are the dominant contributions to the cross sections, and neutrino-induced reaction cross sections on $^{16}$O are investigated [4]. Charged-current cross sections induced by SN neutrinos and their dependence on Mikheyev-Smirnov-Wolfenstein neutrino oscillations are discussed for a future SN burst [5].

[1] T. Suzuki, A. B. Balantekin and T. Kajino, Phys. Rev. C 86, 015502 (2012).
[2] T. Suzuki, A. B. Balantekin, T. Kajino and S. Chiba, J. Phys. G 46, 075103 (2019).
[3] J. M. Berryman, V. Brdar and P. Huber, Phys. Rev. D 99, 055045 (2019).
[4] T. Suzuki, S. Chiba, T. Yoshida, K. Takahashi and H. Umeda, Phys. Rev. C 98, 034613 (2018).
[5] K. Nakazato, T. Suzuki and M. Sakuda, PTEP 2018, 123E02 (2018).

Speaker: Toshio Suzuki (Nihon University)

CNNP2020_Suzuki.pdf

10:00 -

10:00 Axial Vector Form Factors of the Nucleon using lattice QCD

The success of experiments such as DUNE require the determination of neutrino flux and cross-section with nuclear targets with unprecedented accuracy. A crucial input in the calculations of these is the axial form factor. Starting from the standard model that defines the interaction of the axial current with quarks, one needs to include both QCD corrections that bind quarks into nucleons and nuclear effects that arise in heavy nuclear targets such as argon. Experimental access to the first, QCD corrections for nucleons, is prevented by safety concerns posed by liquid hydrogen targets. Axial and electromagnetic form factors of the nucleon can be calculated from first principals using lattice QCD. This talk will show that we now have control over all sources of systematic errors that arise in lattice QCD calculations and the axial form factors satisfy the PCAC relation, an essential and non-trivial check [see arXiv:1905.06470]. Finally, I will present state-of-the-art results at the physical pion mass and in the continuum limit and compare them with phenomenology. Prospects for reaching 1–2% accuracy will be discussed.

Speaker: Rajan Gupta (Los Alamos National Laboratory)

Gupta_CNNP2020_AFF.pdf

10:20 → 10:50 Coffee/Tea Break

10:50 → 12:50 Invited Talks

Convener: Chair: Takaharu Otsuka (Department of Physics, University of Tokyo)

10:50 Quenching of the spin-isospin response in nuclei

Quenching of the Gamow-Teller strength in in weak processes is a well-established phenomenon. I will briefly review our knowledge of quenching of the isospin-analog spin-M1 resonance. The interest is driven by recent developments of ab initio calculations based on interactions derived from χEFT, which allow a unified description of electromagnetic and weak processes populating isospin-analog states. This provides a unique testing ground for the role of two-body currents for the quenching phenomenon. I will also discuss the (very limited) data on quenching of higher multipoles and their implications for astrophysical scenarios and 0vββ decay and present some ideas for future experimental work using transverse electron scattering.

Speaker: Peter von Neumann-Cosel (Institut fuer Kernphysik, Technische Universitaet Darmstadt)

2020 CNNP von Neumann-Cosel.pdf

11:20 Nuclear structure observables to shed light on neutrinoless double-beta decay

Neutrinoless double-beta decay (0nbb) is notoriously difficult to observe. Moreover, expected decay rates depend on the value of the nuclear matrix elements (NMEs) which are poorly known. In order to obtain insights on the NMEs, and therefore on expected decay rates, one can study other processes connected to 0nbb decay. In this talk I confront predictions and measurements of the half-life and beta spectrum of the two-neutrino double-beta decays to test nuclear models used to calculate 0nbb NMEs. In addition, I discuss the relation between 0nbb NMEs (mediated by the weak interaction) and other nuclear observables such as double Gamow-Teller (strong) and double-gamma
(electromagnetic) transitions.

Speaker: Javier Menendez (University of Barcelona)

menendez_capetown.pdf

11:50 Nuclear responses for double beta decay and muon capture

To describe the double beta decay processes reliably one needs a possibility to test the involved virtual transitions against experimental data. In this work we manifest how to utilise
the nuclear and lepton ($\mu$) charge-excange reaction data in the study of $0\nu\beta\beta$ decay and astro-neutrinos. In my contribution I will cover the theoretical aspects of ordinary muon capture (OMC) as well as the recent studies of (3He,t) and charge-echange studies at RCNP, Osaka [1].

The OMC strength function in 100Nb was computed in the pnQRPA framework [2], and compared with the experimental strength function measured at RCNP in Osaka [3]. The calculated first OMC giant resonance in 100Nb is in agreement with the experimental value. However, the computed total OMC strength is higher than the measured strength, which refers to quenched g_A value.
Furthermore, the OMC rates to the daughter nuclei of the $0\nu\beta\beta$ decay triplets of immediate
experimental interest are computed [4] and compared with available data of [5].
The capture rates to the low-lying states of 76As are in accordance with the data. The OMC rates to
the daughter nuclei of $0\nu\beta\beta$ decay triplets are also compared with the corresponding $0\nu\beta\beta$
matrix elements in order to find possible connections between them [6].

Eventually, the OMC process can be used to probe the structure of the intermediate states appearing in the
double-beta-decay process. Future experiments can help fine-tune the nuclear-structure parameters for the
double-beta-decay calculations.

[1] H. Ejiri, J. Suhonen, and K. Zuber, Phys. Rep. 797, 1 (2019).

[2] L. Jokiniemi, J. Suhonen, H. Ejiri, and I. H. Hashim,
Phys. Lett. B 794, 143 (2019).

[3] I. H. Hashim, H. Ejiri, T. Shima, K. Takahisa, A. Sato, Y. Kuno, K. Ninomiya,
N. Kawamura, and Y. Miyake, Phys. Rev. C 97, 014617 (2018).

[4] L. Jokiniemi and J. Suhonen,
Phys. Rev. C 100, 014619 (2019).

[5] D. Zinatulina, V. Brudanin, V. Egorov, C. Petitjean, M. Shirchenko, J. Suhonen, and
I. Yutlandov, Phys. Rev. C 99, 024327 (2019).

[6] L. Jokiniemi, and J. Suhonen, Phys. Rev. C (2020), submitted.

Speaker: Lotta Jokiniemi (University of Jyväskylä)

CNNP2020_Jokiniemi.pdf

12:20 Study of kinematic factors in double-beta decay

S. Stoica,
International Centre for Advanced Training and Research in Physics and
Horia Hulubei National Institute of Physics and Nuclear Engineering,
P.O. Box MG12, 077125 Bucharest-Magurele, Romania

Until the recent past not to much importance was given to the kinematic factors related to the double-beta decay, i.e. the phase space factors, electronic spectra and angular correlations between the emitted electrons. The reason was largely because on the one side they were considered to be calculated/predicted with enough precision (in comparison for example with the nuclear matrix elements) and, on the other side, the experimental measurements had not reached a sufficient degree of accuracy to be able to distinguish fine details of them. This situation is changing now. A detailed analysis of the DBD electron spectra and angular correlations can provide us with useful information on transitions to excited states, on decay modes and mechanisms contributing to neutrinoless DBD and, very recently on possible effects of Lorentz symmetry violation in the neutrino sector.
In my presentation I will give first a short review about the challenges in computation of the space phase factors, electron spectra and electron angular correlations. Then, I refer to the analysis of observable effects of Lorentz violation (LV) in two-neutrino DBD in the framework of the Standard Model Extension (SME) and I present a comparison between the methods of calculation the summed electron spectra including the deviations due to LV associated to the like-time component of the so-called countershaded operator.
Finally, I show that our predictions regarding electronic spectra correlated with their precise measurements that are currently being done in DBD experiments (like EXO-2000, SuperNEMO, etc.) for searching LV effects, can improve with up to 30% the actual upper limits of the (ä)3of coefficient that governs the LV contribution.

References
J. S. Diaz, Phys. Rev. D 89, 036002 (2014).
J. Kotila and F. Iachello, Phys. Rev. C 85, 034314 (2012).
S. Stoica and M. Mirea, Phys. Rev. C88, 037303 (2013).
M. Mirea, T. Pahomi, and S. Stoica, Rom. Rep. Phys.67, 872 (2015).
S. Stoica, MEDEX’19, Prague, May 28, 2019.
S. Stoica and M. Mirea, Phase space factors for double-beta decay, Frontiers in Physics, ID 436288, 2019.

Speaker: Sabin Stoica (International Centre for Advanced Training and Research in Physics)

Stoica_cnnp2020.pdf

13:00 → 14:00 Lunch

14:00 → 14:15 Move to buses

14:15 → 15:30 Bus drive to iThemba LABS

15:30 → 15:50 General announcements and iThemba LABS safety talk

15:50 → 17:50 iThemba LABS tour

18:00 → 20:00 iThemba LABS braai

20:00 → 21:30 Bus to Arabella