Abstract
The Standard Model of particle physics, while successful, does not explain several cosmic mysteries, prompting searches for new physics beyond it. Indirect methods like Drell-Yan angular coefficient measurements provide insights into the electroweak sector and Quantum Chromodynamics (QCD). These measurements analyze the angular distributions of leptons from the Drell-Yan process, decomposing the differential cross-section into angular coefficients (Ai). While Ai has been measured for Z boson production, measuring them for W boson production is challenging due to significant backgrounds and the neutrino in W decays hindering reconstruction of the W rest frame.
This thesis presents methodologies to overcome these challenges using 338.1 inverse picobarns of low-pileup data at a center-of-mass energy of 13 TeV from the ATLAS experiment at CERN. By optimising kinematic selection to probe the Lam-Tung relation in regions of high transverse lepton momentum, the analysis increased fake backgrounds, requiring sophisticated estimation methods through complex three-dimensional binning. Despite remaining difficulties in controlling backgrounds and achieving data fit convergence, this work lays the foundation for future exploration of W-Ai coefficients.
