Electron reconstruction performance and sensitivity determination of the h → ZZ∗ → 4e cross-section at sqrt(s) = 10 TeV Muon Collider

The discovery of the Higgs boson at LHC completed the picture of the Standard Model. However, observations like dark matter and neutrino masses suggest that SM might be incomplete. Also, the Higgs boson and its interactions are yet to be fully characterized. A Future Collider is sought to tackle those challenges. At the highest energies, the goal of such a scientific program will be to directly test Beyond SM hypotheses. At the electroweak energy scale, the main goal will be the characterization of the Higgs boson: the measurement of its self-coupling would lead to the determination of the Higgs potential, while the precise measurement of its coupling with fermions and gauge bosons could hint to new physics in the highest-order corrections, in case a deviation was found. The Muon Collider is a novel machine that could allow both high energy and high precision measurements in a single facility. At sqrt(s)=10 TeV, a Muon Collider overqualifies as a Higgs factory, with high enough single and double Higgs production rates to meet the required accuracies in the Higgs sector’s measurements. However, the huge background expected from the decay of colliding muons could hinder the physics performance of a muon collider experiment, if not mitigated: one of the possibilities to reduce its effect is to exploit the different position, time and energy properties with respect to particles from the hard scattering. In this context, the present thesis aims at characterizing the CRILIN electromagnetic calorimeter, a novel detector technology able to deliver the space, time and energy resolutions required for the Muon Collider’s environment. The work consists in the evaluation of the simulated reconstruction performance of single electrons with the CRILIN calorimeter in presence of the beam-induced background, followed by the optimization of the mitigation strategies. The resulting performance is then exploited in a parametric analysis of the sensitivity to the single SM Higgs decay to two Z0, each decaying to an electron-positron pair.