Speaker
Description
After the discovery of the W and Z bosons at the Super Proton Synchrotron (SPS) at CERN, particles responsible for weak interactions, the efforts have been geared towards measuring their properties. A precise measurement of the W boson properties remains a major test for the validation of the standard model.
In this presentation, the measurement of the W boson transverse momentum $p^{T}_{W}$ and the differential cross sections are described. Using low pile-up data set, collected with low number of interactions per bunch crossing, by the ATLAS detector in 2017 and 2018.
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$\textbf{Measurement of the transverse momentum distribution}$: One of the most important theoretical sources of uncertainties in the measurement of the W-boson mass, is the extrapolation of the $p^{T}$ distribution from Z boson to W-boson (≈ 6 MeV), a direct measurement of $p^{T}_{W}$ would avoid such an extrapolation and the corresponding theoretical modelling uncertainty.
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$\textbf{Measurement of the differential cross sections}$: The measurement of the differential cross sections for the $W$ boson provides stringent tests of the QCD theory, and is crucial for a deep understanding and modelling of QCD interactions. Also, the rapidity dependence of the W boson production in the Drell–Yan process provides constraints on the parton distribution functions (PDFs), which are currently the dominant uncertainty source in the W mass measurement (9.2 MeV).
source: https://tel.archives-ouvertes.fr/tel-03224873
