Abstract
Abstract
In the context of the European strategy for particle physics, the Multi-TeV Muon Collider
has emerged as a compelling alternative for advancing our understanding of the Standard Model,
after the full exploitation of the High-Luminosity LHC. The physics programme at the Muon Collider
includes precise measurements in the Higgs boson sector and the search for new physics at the TeV
scale. Achieving these goals relies on accurate full event reconstruction, including the
identification and precise four-momentum estimation of various particles. The Particle Flow (PF)
algorithm is one of the most suitable approach for this task, exploiting information from
tracking, calorimeter, and muon detectors for particle identification and measurements of their
momenta/energies. Tracking detectors measure charged particle momenta, while calorimeters provide
energy measurements for photons and neutral hadrons. Therefore, a combination of an exceptional
tracking system and high-granularity calorimeters is necessary. However, one of the biggest
challenges for a future experiment at the Muon Collider is to discriminate the product of the
μμ collisions from the intense beam-induced-background (BIB), due to the unstable nature of
muons, whose decay products interact with the detector material. To address this, an innovative
hadronic calorimeter (HCAL) based on Micro Pattern Gas Detectors (MPGDs) is proposed. MPGDs offer
robust technology for high radiation environments and a high granularity for precise spatial
measurements. Dedicated studies are needed to assess and optimize the performance of an MPGD-based
HCAL, including the development of medium-scale prototypes for performance measurements. The
response of HCAL to incoming particles is examined through Monte Carlo simulations using Geant4,
comparing the performance of digital and semi-digital readouts, with energy resolution as the
figure of merit. The simulated geometry will be integrated into the Muon Collider software to
study its impact on jet reconstruction within the full apparatus and in the presence of BIB. The
simulation will be also validated through the test of a small-size calorimeter cell equipped with
advanced resistive MPGD technologies, namely resistive MicroMegas, resistive μRWELL and
RP-WELL.