Study of antideuteron production from antilambda-b at the LHC

This thesis presents a study of a newly proposed decay channel of the anti-Λb baryon into antideuterons at the LHC. This analysis is motivated by the implications for the observation of such a channel for indirect dark matter searches and our understanding of antinuclei formation mechanisms via coalescence. In the universe, the production of antinuclei is highly suppressed. Specifically, for kinetic energies per nucleon below 1 GeV/n, the antideuteron flux from astrophysical sources is expected to be approximately three orders of magnitude lower than the predicted flux from processes involving dark matter particles, e.g. Weakly Interacting Massive Particles (WIMPs). In this study, proton-proton collisions at the highest-reached LHC energy of√s = 13.6 TeV are simulated using the Monte Carlo event generator PYTHIA, from which the production of anti-Λb is obtained. Coalescence models are then applied to the antinucleons produced in the final state to produce antideuterons. In particular, two coalescence models are presented: one based on a classical description of the process and a state-of-the-art coalescence model based on a quantum mechanical approach. For both models, a first estimate of the branching ratio of the anti-Λb → anti-d + X process is provided, never reported before in the literature. Furthermore, the acceptance of the ALICE and LHCb detectors is compared, evaluating their potential to detect antideuterons produced from anti-Λb decays.