Seminarium "Teoria cząstek elementarnych i kosmologia"

We study the pair production of the long-lived mediator particles from the decay of the SM Higgs boson and their subsequent decay into standard model particles. We discuss triggering of such events using the HL-LHC upgrades and compute the projected sensitivity of using the muon spectrometer of the CMS detector at the HL-LHC experiment, along with dedicated detectors for LLP searches like CODEX-b and MATHUSLA. Subsequently, we study the improvement with the FCC-hh detector at the 100 TeV collider experiment for such long-lived mediators, again focusing on the muon spectrometer. We propose dedicated LLP detector designs for the 100 TeV collider experiment, DELIGHT (Detector for long-lived particles at high energy of 100 TeV) and study their sensitivities. We conclude by discussing the rich landscape of experimental proposals for exploring the lifetime frontier.