Comunicazione
Data-driven performance of muon momentum scale at CMS using the $Z$ boson mass as a standard candle.
Alexe C.A.
An essential ingredient for the physics program of the CMS experiment at the Large Hadron Collider (LHC) is the accurate measurement of the momentum of charged particles using the CMS Tracker. In this communication, we report on a data-driven study of the muon momentum scale at CMS using the $Z$ boson mass as a standard candle. The study is performed using data from proton-proton collisions at 13 TeV, collected by the CMS detector during the LHC Run 2 period. The $Z$ boson mass is reconstructed from pairs of muons with opposite charge and with an invariant mass near the world average measurement. We perform a fit of the $Z$ boson peak position and width and extract the muon momentum scale correction factors due to correlated geometrical distortions, known as weak modes. The corrections due to weak modes are determined after the standard calibration and alignment of the tracks has been applied, thus a gain in the accuracy of the momentum scale is obtained as a result of the presented work. The improvement in momentum scale determination will enhance the precision of physics analyses performed at CMS, ranging from precision measurements such as the $W$ mass to searching for new physics.