The measurement of W±boson charge asymmetry at $\sqrt{s}$ = 13 TeV with the CMS detector using the 2015 data set and a global QCD analysis on this asymmetry

This thesis presents physics results accomplished during the 2017-2019 years in the CMS experiment. Three main contributions are discussed: a measurement of diamond sensors for the BCM1F luminometer and monitoring of its performance during the whole Run 2; a measurement of differential cross-sections of W± boson production in the muon channel as a function of pseudorapidity at $\sqrt{s}$ = 13 TeV using 2015 data set,and extraction of W± boson charge asymmetry values; a global QCD analysis with the obtained asymmetry results. During 2016-2017 in DESY-Zeuthen laboratories, twelve poly-crystalline Chemical Vapour Deposited (pCVD), and five single-crystalline Chemical Vapour Deposited(sCVD) diamonds were tested to select the most suitable sensors for the BCM1F upgrade, scheduled during a short technical stop at the end of 2017. In these studies,each sensor was tested for the leakage current durability, current over time stability, and charge collection distance constancy. During Run 2, the stability of diamond sensors performance was monitored and analyzed. These results allowed to broaden our knowledge about technical aspects of luminosity measurement with diamond sensors in severe conditions of radiation damage and were considered in the next design generation of luminometers. The extraction of W± boson charge asymmetry was performed starting from the analysis of the "Measurement of inclusive W± and Z$^{0}$ boson production cross-sections???in pp collisions and luminosity calibration at $\sqrt{s}$ = 13 TeV using a data sample collected with the CMS detector in 2015 with a corresponding integrated luminosity of 2.2±0.05 fb$^{-1}$. The asymmetry was calculated by measuring differential cross-sections of W± boson production in the muon channel as a function of pseudorapidity. The obtained results of differential cross-sections and asymmetry values were compared with theoretical predictions at NNLO, produced using different PDF sets. The final results are presented with the full set of systematic uncertainties, showing good agreement with theoretical predictions, within the uncertainty range. The final part is dedicated to two global QCD analyses made using the measured asymmetry. Studies were performed using a global QCD fit approach, implemented in the xFitter framework. In the first analysis, the measured asymmetry was tested on its sensitivity to proton structure using combined DIS results from the H1 and ZEUS experiments. The inclusion of the asymmetry values showed a good improvement of valence quark distributions in a range of 10$^{-3}$ $\leq$ x $\leq$ 10 $^{-1}$ . The second analysis was performed with DIS data and CMS results of previous measurements of W± boson charge asymmetry and W± boson + charm quark production. The impact of the W± boson charge asymmetry, measured in this thesis, is presented with the full set of experimental, model, and parameterization systematic uncertainties. The final results showed an improvement in the distribution of the up valence quark distribution.