Particle and Astroparticle Physics Seminar

Searches for ultra long-lived particles with MATHUSLA

Miriam Diamond

University of Toronto

The observation of neutral long-lived particles (LLPs) at the LHC would reveal physics beyond the Standard Model and could account for the many open issues in our understanding of our universe. LLP signatures are well motivated and can appear in many theoretical constructs that address the Hierarchy Problem, Dark Matter, Neutrino Masses and the Baryon Asymmetry of the Universe. With the current experiments at particle accelerators, however, no search strategy will be able to observe the decay of neutral LLPs with masses above the GeV scale and proper lifetimes at the limit set by Big Bang Nucleosynthesis, 10^7-10^8 m. Hence the MATHUSLA detector concept (MAssive Timing Hodoscope for Ultra-Stable neutraL pArticles) will be presented. It can be implemented on the surface above the CMS detector in time for the high-luminosity LHC operations, to search for such neutral LLPs. The large area of the detector allows MATHUSLA to make important contributions to cosmic ray physics as well. This talk will report on the analysis of data collected by a test stand installed on the surface above the ATLAS detector, ongoing background studies, and plans for the detector design and construction.