A high efficiency photon veto for the Light Dark Matter eXperiment

Journal Article · 01 April 2020 · Journal of High Energy Physics (Online)

DOI: https://doi.org/10.1007/JHEP04(2020)003 · OSTI ID:1608809

Åkesson, Torsten; Blinov, Nikita; Bryngemark, Lene; Colegrove, Owen; Collura, Giulia; Dukes, Craig; Dutta, Valentina; Echenard, Bertrand; Eichlersmith, Thomas; Group, Craig; Hiltbrand, Joshua; Hitlin, David G.; Incandela, Joseph; Krnjaic, Gordan; Lazaro, Juan; Li, Amina; Mans, Jeremiah; Masterson, Phillip; McCormick, Jeremy; Moreno, Omar ; Mullier, Geoffrey; Nagar, Akshay; Nelson, Timothy; Niendorf, Gavin; Oyang, James; Petersen, Reese; Pöttgen, Ruth; Schuster, Philip; Siegel, Harrison; Toro, Natalia; Tran, Nhan; Whitbeck, Andrew

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.

• Research Organization: SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States); Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE; USDOE Office of Science (SC), High Energy Physics (HEP)
• Contributing Organization: The LDMX collaboration
• Grant/Contract Number: AC02-76SF00515; AC02-07CH11359
• OSTI ID: 1608809
• Alternate ID(s): OSTI ID: 1614743
• Report Number(s): FERMILAB-PUB-19-620-SCD; SLAC-PUB-17495; arXiv:1912.05535; TRN: US2105104
• Journal Information: Journal of High Energy Physics (Online), Vol. 2020, Issue 4; ISSN 1029-8479
• Publisher: Springer BerlinCopyright Statement
• Country of Publication: United States
• Language: English