A High Efficiency Photon Veto for the Light Dark Matter eXperiment
Abstract
Fixed-target experiments using primary electron beams can be powerful discovery tools for light dark matter in the sub-GeV mass range. The Light Dark Matter eXperiment (LDMX) is designed to measure missing momentum in high-rate electron fixed-target reactions with beam energies of 4 GeV to 16 GeV. A prerequisite for achieving several important sensitivity milestones is the capability to efficiently reject backgrounds associated with few-GeV bremsstrahlung, by twelve orders of magnitude, while maintaining high efficiency for signal. The primary challenge arises from events with photo-nuclear reactions faking the missing-momentum property of a dark matter signal. We present a methodology developed for the LDMX detector concept that is capable of the required rejection. By employing a detailed GEANT4-based model of the detector response, we demonstrate that the sampling calorimetry proposed for LDMX can achieve better than rejection of few-GeV photons. This suggests that the luminosity-limited sensitivity of LDMX can be realized at 4 GeV and higher beam energies.
Cite
@article{arxiv.1912.05535,
title = {A High Efficiency Photon Veto for the Light Dark Matter eXperiment},
author = {Torsten Åkesson and Nikita Blinov and Lene Bryngemark and Owen Colegrove and Giulia Collura and Craig Dukes. Valentina Dutta and Bertrand Echenard and Thomas Eichlersmith and Craig Group and Joshua Hiltbrand and David G. Hitlin and Joseph Incandela and Gordan Krnjaic and Juan Lazaro and Amina Li and Jeremiah Mans and Phillip Masterson and Jeremy McCormick and Omar Moreno and Geoffrey Mullier and Akshay Nagar and Timothy Nelson and Gavin Niendorf and James Oyang and Reese Petersen and Ruth Pöttgen and Philip Schuster and Harrison Siegel and Natalia Toro and Nhan Tran and Andrew Whitbeck},
journal= {arXiv preprint arXiv:1912.05535},
year = {2019}
}