# Foraging for dark matter in large volume liquid scintillator neutrino detectors with multiscatter events

Bramante, Joseph (The McDonald Institute and Department of Physics, Engineering Physics, and Astronomy, Queen’s University, Kingston, Ontario K7L 2S8, Canada) (Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2J 2W9, Canada) ; Broerman, Benjamin (The McDonald Institute and Department of Physics, Engineering Physics, and Astronomy, Queen’s University, Kingston, Ontario K7L 2S8, Canada) ; Kumar, Jason (Department of Physics and Astronomy, University of Hawaii, Honolulu, Hawaii 96822, USA) ; Lang, Rafael F. (Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA) ; Pospelov, Maxim (Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2J 2W9, Canada) (Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia V8P 5C2, Canada) ; Raj, Nirmal (TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada)

16 April 2019

Abstract: We show that dark matter with a per-nucleon scattering cross section $\gtrsim {10}^{-28}\text{}\text{}{\mathrm{cm}}^{2}$ could be discovered by liquid scintillator neutrino detectors like Borexino, $\mathrm{SNO}+$, and JUNO. Due to the large dark matter fluxes admitted, these detectors could find dark matter with masses up to $1{0}^{21}\text{}\text{}\mathrm{GeV}$, surpassing the mass sensitivity of current direct detection experiments (such as XENON1T and PICO) by over 2 orders of magnitude. We derive the spin-independent and spin-dependent cross section sensitivity of these detectors using existing selection triggers, and we propose an improved trigger program that enhances this sensitivity by 2 orders of magnitude. We interpret these sensitivities in terms of three dark matter scenarios: (1) effective contact operators for scattering, (2) QCD-charged dark matter, and (3) a recently proposed model of Planck-mass baryon-charged dark matter. We calculate the flux attenuation of dark matter at these detectors due to the earth overburden, taking into account the earth’s density profile and elemental composition, as well as nuclear spins.

Published in: Physical Review D 99 (2019)