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SUMMARY:Q-value measurements of rare weak beta decays with JYFLTRAP
DTSTART;VALUE=DATE-TIME:20200225T130000Z
DTEND;VALUE=DATE-TIME:20200225T132000Z
DTSTAMP;VALUE=DATE-TIME:20260612T051316Z
UID:indico-contribution-1458@indico.tlabs.ac.za
DESCRIPTION:Speakers: Tommi Eronen (University of Jyväskylä)\nRare weak 
 beta decays can be potentially used in searches for the neutrino mass. The
 se 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. \n\nThere 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 spect
 rum. First\, before any attempt to measure the endpoint spectrum\, it is n
 ecessary to confirm whether the $Q$-value of the decay is positive. The gr
 ound-state-to-ground state $Q$-value can be measured with mass spectrometr
 y while the excitation energy of the excited state in the daughter can be 
 deduced from gamma-ray spectroscopy.\nUsing the JYFLTRAP Penning trap setu
 p [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 1
 00-eV level. Along with this Q-value measurement I’ll give an overview o
 f the used Phase-Imaging Ion-Cyclotron mass measurement technique [6].\n\n
 [1] B.J. Mount\, M. Redshaw\, E.G. Myers\, Phys. Rev. Lett. **103**\, 1225
 02 (2009).\n[2] J. S. E. Wieslander\, J. Suhonen\, T. Eronen et al.\, Phys
 . Rev. Lett. **103**\, 122501 (2009).\n[3] H. Ejiri\, J. Suhonen\, K. Zube
 r\, Phys. Rep. **797**\, 1-102 (2019).\n[4] T. Eronen et al.\, Eur. Phys. 
 J. A **48**\, 46 (2012).\n[5] D. Nesterenko et al.\, Eur. Phys. J. A **54*
 *\, 154 (2018).\n[6] S. Eliseev et al.\, Appl. Phys. B **114**\, 107 (2014
 ).\n\nhttps://indico.tlabs.ac.za/event/85/contributions/1458/
LOCATION:Parallel Venue
URL:https://indico.tlabs.ac.za/event/85/contributions/1458/
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