| Abstract [eng] |
The Drell-Yan (DY) process – annihilation of a quark and antiquark into a virtual photon or Z boson decaying into a pair of oppositely charged leptons – is one of the most important benchmark processes at hadron colliders. It allows precision tests of Standard Model (SM) predictions, refinement of proton parton distribution functions, and improved background modeling for new-physics searches. The High-Luminosity LHC (HL-LHC) upgrade will greatly increase the collected data volume, so the CMS detector – especially its Inner Tracker – must undergo a major Phase-2 upgrade to maintain performance under much higher radiation levels and pileup. This dissertation presents a high-precision measurement of the DY differential cross section dσ/dm using the full CMS Run 2 (2016–2018) dataset, focusing on background estimation methods for misidentified leptons and top-quark production. It also describes preparatory work for the CMS Phase-2 Inner Tracker upgrade: calibration and performance studies of the RD53B-CMS (CROCv1) pixel readout chip prototype, and contributions to developing the Ph2-ACF software. Finally, Monte Carlo simulation is used to assess how the upgraded detector will affect future DY measurement precision under HL-LHC conditions, showing that muon reconstruction efficiency stays high while the resolution of key kinematic quantities improves significantly. |
