Particle Detection and Measurement: From Low-Energy Nuclear Fusion with STELLA to High-Energy Muon Momentum Calibration with ATLAS

Abstract

This thesis presents a study of particle detection and measurement spanning from low energy nuclear fusion experiments at STELLA to high-energy muon calibration studies at the ATLAS detector. The first part of the study focuses on the measurement of the fusion cross-section and spin assignment for the 12𝐶 + 12𝐶 reaction at 𝐸𝑐𝑚 = 5.02 MeV using the STELLA experimental setup. Charged particle detection techniques, cross-section evaluation, and Legendre polynomial fits were employed to determine resonance structures in the compound nucleus 24𝑀𝑔. The results confirm a spin-parity assignment of 𝐽𝜋 = 2+, consistent with previous studies, and provide valuable insights for astrophysical models of stellar evolution.

The second part of the study shifts to high-energy physics, focusing on muon momentum calibration at ATLAS for precise 𝑍-boson mass measurements. The calibration technique employs 𝐽/𝜓 decays to address charge-dependent and charge-independent biases in transverse momentum measurements. Using data from Run-2 of the LHC, the analysis refines muon track parameters within the Inner Detector, improving the accuracy of the reconstructed 𝑍-boson mass. This calibration is crucial for reducing systematic uncertainties in electroweak precision measurements, directly impacting the determination of fundamental parameters such as the 𝑊-boson mass and weak mixing angle.