The search for physics Beyond the Standard Model using the Coherent CAPTAIN-Mills detector at Los Alamos National Laboratory*

    The Coherent CAPTAIN-Mills (CCM) experiment is a 10-ton liquid argon (LAr) detector located at Los Alamos National Laboratory (LANL) and has collected data in search of evidence for light dark matter (LDM) starting with the engineering run in 2019.  Analysis of the 6-week engineering run (CCM120) shows that the detector is competitive at setting limits in the vector portal dark matter model, and at the same time excludes LDM masses (9 – 50 MeV) in the leptophobic dark matter model.  The operation of CCM is strictly light based with a threshold of 50 keV and uses coherent elastic scattering off argon nuclei to detect LDM.  

    The upgraded CCM detector (CCM200) is now fitted with 200 photomultiplier tubes (PMTs) along with increased shielding to further limit backgrounds and improve overall sensitivity.  The upgraded CCM detector can explore Beyond the Standard Model (BSM) physics such as dark sector solutions to the MiniBooNE excess due to possibly long-lived particles resulting from neutral and charged meson decays.  Another area of exploration includes the search for axionlike particles (ALPs) where ALPs coupled primarily to photons can give rise to a gamma ray signal in the CCM detector.  The enhanced sensitivity of the CCM detector will improve our ability to explore ALP-photon and ALP-electron couplings.