Master's Thesis - Drell-Yan Process at CMS

Data Analysis of the Drell-Yan Process at the CMS Experiment.

Centered on the Drell–Yan process at the LHC, this project involved working with real experimental and Run 2 Monte Carlo data from the CMS experiment to study Standard Model processes in a complex collider environment. The analysis focused on the $ Z \rightarrow e^{+}e^{-}$ channel, with the goal of validating analysis strategies and isolating a clean Z boson signal.

Research Focus

Using CMS Run-2 MC samples, the analysis involved:

  • Signal Extraction: Isolation of the $ Z \rightarrow e^{+}e^{-}$ mass peak through precision event selection and background suppression
  • Event Selection Strategy: Implementation of optimized kinematic cuts, lepton isolation criteria, and quality requirements
  • Background Rejection: Suppression of dominant simulated and electroweak backgrounds to obtain a clean signal region

Technical Implementation

The analysis pipeline involved:

  • Developing C++-based ROOT scripts to automate event filtering, selection, and histogram production
  • Implementing structured workflows from initial data handling to final statistical interpretation
  • Performing statistical analysis to evaluate signal significance and distribution properties

Physics Impact

This work provided:

  • A robust foundation in high-energy physics data analysis techniques
  • Practical experience with collider data, Monte Carlo validation, and background modeling
  • Training in precision measurements within the Standard Model framework
  • Exposure to modern, data-driven research workflows used in large-scale collider experiments

The Drell–Yan process, particularly the Z boson resonance, serves as a standard benchmark at the LHC and remains essential for validating detector performance, reconstruction algorithms, and theoretical predictions.