Clusterization and background estimation of a direct photon signal in pp collisions at √s=13.6 TeV in ALICE

Abstract

This thesis presents a method to estimate the background contribution in a direct photon signal in proton-proton collisions at √s = 13.6 TeV in ALICE. This work serves as an initial step towards a comprehensive jet quenching study using Run 3 data. To estimate the background contribution, a new EMCAL clusterizer was implemented and advanced data selection techniques were applied. This thesis introduces and validates a suitable clusterizer for direct photon measurements. Additionally, it provides data selection criteria for isolating the direct photon signal. The estimated background contribution was found to be underestimated. Which is likely due to various factors associated with the used Monte Carlo dataset. However, the specific sources and magnitudes of these errors remain unclear and can be further investigated