Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published April 2020 | Published + Submitted
Journal Article Open

A high efficiency photon veto for the Light Dark Matter eXperiment


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 10⁻¹³ rejection of few-GeV photons. This suggests that the luminosity-limited sensitivity of LDMX can be realized at 4 GeV and higher beam energies.

Additional Information

© 2020 The Author(s). This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited. Article funded by SCOAP3. Received: December 18, 2019; Revised: February 20, 2020; Accepted: February 28, 2020; Published: April 1, 2020. Support for UCSB involvement in LDMX is made possible by the Joe and Pat Yzurdiaga endowed chair in experimental science. Use was made of the computational facilities administered by the Center for Scientific Computing at the CNSI and MRL (an NSF MRSEC; DMR-1720256) and purchased through NSF CNS-1725797. TA acknowledges support from the Royal Physiographic Society of Lund. RP acknowledges support through The L'Oréal-UNESCO in Sweden Prize with support of the Young Academy of Sweden. OM, TN, PS and NT are supported by the U.S. Department of Energy under Contract No. 703 DE-AC02-76SF00515. GK and NT are supported by the Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics. BE and DH are supported by the US Department of Energy under grant DE-SC0011925. LB acknowledges support from the Knut and Alice Wallenberg Foundation.

Attached Files

Published - Åkesson2020_Article_AHighEfficiencyPhotonVetoForTh.pdf

Submitted - 1912.05535.pdf


Files (20.2 MB)
Name Size Download all
6.2 MB Preview Download
14.0 MB Preview Download

Additional details

August 19, 2023
October 20, 2023