Electroweak precision measurements with the CMS detector

TL;DR

This paper presents a highly precise measurement of the effective weak mixing angle using Drell-Yan events at the CMS detector, achieving reduced uncertainties through advanced analysis techniques and large data samples.

Contribution

It introduces new analysis methods and utilizes large datasets to significantly improve the precision of electroweak measurements at the LHC.

Findings

Effective weak mixing angle measured as 0.23101 with total uncertainty of 0.00052.

Uncertainties reduced by a factor of two compared to previous LHC measurements.

Results are consistent with the Standard Model predictions.

Abstract

We report on a precision measurement of the effective weak mixing angle using the forward-backward asymmetry of Drell-Yan ($ee$ and $\mu\mu$) events in pp collisions at $\sqrt{s}=8~\mathrm{TeV}$ at CMS. The data sample corresponds to an integrated luminosity of $18.8~\mathrm{fb}^{-1}$ and $19.6~\mathrm{fb}^{-1}$ for muon and electron channels, respectively. The sample consists of 8.2 million dimuon and 4.9 million dielectron events. With new analysis techniques and large samples the statistical and systematic uncertainties are reduced by a factor of two compared to previous measurements at the LHC. The extracted value of the effective weak mixing angle from the combined $ee$ and $\mu\mu$ data samples is $ sin^2\theta^{lept}_{eff}=0.23101\pm 0.00036(stat)\pm 0.00018(syst)\pm 0.00016(theory)\pm 0.00030(pdf)$ or $ sin^2\theta^{lept}_{eff}=0.23101\pm0.00052$.