Abstract
The search for relativistic scattering signals of cosmogenic light dark
matter at terrestrial detectors has received increasing attention as an
alternative approach to probe dark-sector physics. Large-volume neutrino
experiments are well motivated for searches of dark matter that interacts very
weakly with Standard Model particles and/or that exhibits a small incoming
flux. We perform a dedicated signal sensitivity study for a detector similar to
the one proposed by the DUNE Collaboration for cosmogenic dark-matter signals
resulting from a non-minimal multi-particle dark-sector scenario. The liquid
argon time projection chamber technology adopted for the DUNE detectors is
particularly suited for searching for complicated signatures owing to good
measurement resolution and particle identification, as well as $dE/dx$
measurements to recognize merged tracks. Taking inelastic boosted dark matter
as our benchmark scenario that allows for multiple visible particles in the
final state, we demonstrate that the DUNE far detectors have a great potential
for probing scattering signals induced by relativistic light dark matter.
Detector effects and backgrounds have been estimated and taken into account.
Model-dependent and model-independent expected sensitivity limits for a
DUNE-like detector are presented.