Low-Mass Drell-Yan Cross-Section Measurements with the LHCb Experiment

Abstract

The LHCb experiment is one of the four main experiments at CERN's flagship accelerator LHC. It is designed for the study of particles containing $b$ or $c$ quarks. However, due to its very forward angular coverage of approximately 30 to 250 mrad, the experiment is well suited to contribute to electroweak physics as well. Measurements of electroweak boson production at LHCb provide important insight into the parton distribution functions of the proton. In addition precision measurements can test the Standard Model where predictions are most precise. This thesis presents the measurements of the low-mass Drell-Yan production cross section with subsequent decay into two muons. For the main analysis, the full 1 fb$^{-1}$ collected by LHCb in 2011 at $\sqrt{s}$ = 7 $TeV$ is analysed. The cross section is measured differentially as a function of the di-muon mass and the di-muon rapidity. The results obtained are in agreement with the predictions calculated at next-to-next-to leading order in perturbative quantum chromodynamics. The previous measurement based on the data collected in 2010 is included in the appendix of this thesis