Measurements of Pion and Muon Nuclear Capture at Rest on Argon in the LArIAT Experiment
Miguel Angel Hernandez Morquecho
Graduate Student
Illinois Institute of Technology
LArIAT is a liquid argon time projection chamber (LArTPC) experiment in a test beam, took data at Fermilab from 2015 to 2017 to understand and characterize interactions of particles in LAr which are commonly observed in neutrino-Ar final-states. In LArTPCs tracks for pions and muons that stop in the TPC have similar ionization profiles, making the particle identification hard. We are presenting unique new particle discrimination capabilities using “blips”, small, isolated ionization depositions reconstructed near the endpoint of stopping tracks. These blips are formed by gammas emitted when an at-rest pion or muon captures on the argon nucleus. The relatively low beam energy provided by LArIAT makes it uniquely suited for performing this demonstration. We present an overview of event candidate selection, blip reconstruction, and background subtraction corresponding to our signal of interest, nuclear captures of pions and muons at rest inside LArIAT's TPC.