Precision EW results from CMS

Abstract

Precision measurements of the properties of W and Z bosons at hadron colliders are a powerful tool to test the internal consistency of the Standard Model (SM) of particle physics. Theoretical predictions of their total production cross section, as well as differential distributions, are often available with next-to-leading order accuracy or beyond in both the strong and electroweak (EW) coupling constants with sub-percent precision. The large amount of data collected at the CERN Large Hadron Collider (LHC) in proton-proton collisions at a center-of-mass energy of 8 and 13 TeV provides an unprecedented opportunity to perform precision measurements of the EW sector of the SM with negligible statistical uncertainty. These measurements allow to test perturbative quantum chromodynamics and EW calculations, and are extremely valuable to set stringent constraints on the parton distribution functions. The deep understanding of the production of EW bosons at the LHC is a fundamental ingredient to perform precision measurements of the SM, and is also mandatory to discover new physics. Indeed, the largest source of irreducible background in many searches for new phenomena is represented by the production of undetected neutrinos from decays of W and Z bosons, and the typical experimental signature for a new physics signal is given by deviations from the precise SM prediction of kinematics distributions. This paper describes some of the most recent EW precision measurements performed by the CMS Collaboration at the LHC. These measurements provide the theoretical community with precious information that will support the development of more accurate predictions. In addition, these results improve the current knowledge of the EW sector and will help chart the course for future measurements.