The extended-track event reconstruction for MiniBooNE

The Booster Neutrino Experiment (MiniBooNE) searches for ν μ → ν e oscillations using the ~ 1 GeV neutrino beam produced by the FNAL Booster synchrotron. The array of photomultiplier tubes (PMTs) lining the MiniBooNE detector records Cherenkov and scintillation photons from the charged particles produced in neutrino interactions. We describe a maximum likelihood fitting algorithm used to reconstruct the basic properties (position, direction, energy) of these particles from the charges and times measured by the PMTs. The likelihoods returned from fitting an event to different particle hypotheses are used to categorize it as a signal ν e event or as one of the background ν μ processes, in particular charged current quasi-elastic scattering and neutral current π 0 production. The reconstruction and event selection techniques described here can be applied to current and future neutrino experiments using similar Cherenkov-based detection.