Speaker
Description
In particle physics, the Glashow-Weinberg-Salam (GWS) model of the electroweak (EW) interactions describes the fundamental parameters, i.e, coupling constant ($\alpha_{EM}$), Fermi constant ($G_{F}$), W boson mass ($M_{W}$), Z boson mass ($M_{Z}$) and $\theta_{W}$, referred as the Weak Mixing Angle or the Weinberg Angle. This angle is a fundamental parameter in the Standard model (SM), probing mixing of W and B fields and can be defined as,
$\sin^{2}\theta_{W}$ = 1- $\frac{M_{W}^{2}}{M_{Z}^{2}}$.
Due to the difference of the Z boson couplings for the left-handed and right-handed fermions (f), an asymmetry is observed in the angular distribution between the oppositely charged leptons produced in Z-boson decays. This asymmetry depends on the weak mixing angle between the neutral states associated to the U(1) and SU(2) gauge groups. To all order in perturbation theory, the effective weak mixing angle ($sin^{2}\theta_{eff}^{f}$) is related to the vector ($g_{V}^{f}$) and axial vector couplings ($g_{A}^{f}$). This is identical for all leptons because of lepton universality. At present, the two most precise experimental measurements (LEP, SLD) disagree by about 3$\sigma$.
Therefore, the non-SM process dependence should be investigated further to get a hint for new physics. Also, this measurement is an overall test of the EW sector. This is also an indirect measurement of the mass of the W-boson. So, the precise measurement of the weak mixing angle is a study of immense importance.
A precision extraction using high luminosity LHC (HL-LHC) data can help settle the long standing issue of the discrepancy between precise measurement from LEP and SLD data. Searches at HL-LHC will profit from the much larger statistics, slightly higher energy and upgraded detectors. Additionally, extending the pseudo-rapidity acceptance with the upgraded detectors is expected to significantly reduce both the statistical and PDF uncertainties. Direct searches for new physics will continue at the HL-LHC with enhanced sensitivity. These all possibilities will be discussed in details. Also, the effect of the recently found (by CDF Collaboration) W-boson mass on the precise measurement of the electroweak fundamental parameters will be discussed. Emphasis will be given on the predictions from theory and simulations regarding the measurement of asymmetry, parton distribution functions, higher order effects, etc. We hope that the results will generate much interest among the scientific community as these are very important findings to predict the future experimental measurements.
| Session | Top Quark and EW Physics |
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