Identification and reconstruction of low-energy electrons in the ProtoDUNE-SP detector

In this poster, we describe the selection and reconstruction of low energy electrons in the ProtoDUNE-SP detector. ProtoDUNE-SP is one of the prototypes for the Deep Underground Neutrino Experiment (DUNE) far detector, built and operated at CERN as a charged particle test beam experiment. The experiment collected data from August 2018 to July 2020. The analysis described here employs a fully automatic event selection and charged particle track reconstruction to obtain a sample of candidate cosmic muons, and to identify low-energy electrons around the end positions of selected candidate muons. Low-energy electron candidates are reconstructed using tools developed as a part of this analysis and the energy spectrum for low-energy electrons is obtained that can be used to evaluate ProtoDUNE-SP (and ultimately the DUNE far detector) response to electrons with energies up to ~50 MeV. Studies have been performed to verify the high purity (~95%) of selected Michel electron event candidates and to calibrate the low-energy electron energy scale with both the cosmic-muon dE/dx method and with use of the theoretical Michel electron energy spectrum. In addition, the effects of detector response to low-energy electrons including readout electronics threshold effects are quantified. Finally, the relation between the theoretical and reconstructed low-energy electron energy spectrum is derived and the energy resolution is characterized.