Beyond the Standard Model Searches with Coherent CAPTAIN Mills

Searches for beyond the standard model (BSM) physics have been ongoing for decades. The use of accelerators to produce boosted low mass particles offers a path to detect potential BSM particles at mass scales below 1 GeV. The Coherent CAPTAIN Mills (CCM) experiment uses a 10-ton liquid argon scintillation detector at the Lujan Center at LANSCE to search for physics beyond the standard model. Such physics includes vector portal light dark matter (LDM), axions, and axion like particles (ALPs). The Lujan Center delivers a 100-kW, 800 MeV, 290 ns wide proton pulse onto a tungsten target at 20 Hz to generate a stopped pion source. The fast pulse, in combination with the speed of the CCM scintillation detector, is crucial for isolating prompt speed of light particles generated by the stopped pion source and reducing neutron and steady state background. In this talk I will describe CCM's search for BSM physics by showing the results from our Fall 2019 search for LDM and ALPs, as well as the projected reach of the experiment based on the current upgrades to the CCM detector for a 3-year run.