Investigation of gluon saturation using di-hadron correlation and assessing efficiency and resolution of ePIC detector in EIC

Abstract

This thesis investigates the phenomenon of gluon saturation in quantum chromodynamics (QCD) by analyzing di-hadron correlations in highenergy nuclear collisions and evaluates the tracking performance of the ePIC detector for the upcoming Electron-Ion Collider (EIC). Gluon saturation, expected at high parton densities, leads to nonlinear effects that alter particle production and correlation patterns. Using data from the STAR experiment at RHIC, the study examines azimuthal correlations between pairs of hadrons in proton-proton and deuteron-gold collisions. The results reveal a significant suppression and broadening of the back-to-back (away-side) peak in central deuteron-gold collisions, providing evidence for gluon saturation effects that cannot be explained by conventional models. The thesis also assesses the efficiency and momentum resolution of the ePIC detector through simulation studies focused on charged pion reconstruction. Both idealized (truth-seeded) and realistic (real-seeded) tracking methods are evaluated. Overall, this work demonstrates that di-hadron correlations are a sensitive probe of gluon saturation and establishes the readiness of the ePIC detector for exploring QCD dynamics in high-density regimes.