Thesis

The precise measurement of the Higgs boson’s properties is a major challenge in particle physics and a fundamental test of the Standard Model. This thesis proposes to improve the measurement of its mass and the constraints on its natural width in the diphoton decay channel (H ? ??), by exploiting data from Run 3 of the CMS experiment at the LHC.
The project relies on developing new artificial intelligence-based calibration methods for the CMS electromagnetic calorimeter. Building on the IJazZ2.0 method developed at CEA/Irfu, the goal is to replace a calibration relying on a few hundred parameters with a continuous, multidimensional correction. Modern generative models will enable the rapid simulation of Z ? ee decays under kinematic constraints and improve both the energy scale and resolution of electrons and photons.
This thesis will thus combine artificial intelligence, instrumental physics, and precision measurements to deepen our understanding of the fundamental properties of the Higgs boson.