Investigating the collinear splitting effects of boosted dark matter at neutrino detectors

TL;DR

This paper explores how boosted dark matter interacts with electrons at neutrino detectors, analyzing effects like collinear splitting and dark photon contributions, and assesses experimental sensitivities and constraints.

Contribution

It introduces a detailed analysis of collinear splitting effects and dark photon contributions in boosted dark matter detection at neutrino experiments, including the use of DM PDFs.

Findings

DUNE and JUNO have high sensitivity to dark photon components in DM.

Logarithmic effects reduce electron recoil rates in neutrino detectors.

Bullet Cluster constraints limit DM self-scattering cross sections.

Abstract

We study the probing prospects of cosmic ray boosted dark matter (DM) in the framework of simplified electron-philic dark photon model. Focusing on the dark matter and dark photon masses around keV $\sim $ MeV scale, we consider the bounds obtained from the XENON1T and Super-K experiments. The electron bound state effects are treated carefully in calculating the XENON1T constraint. As for the detection at neutrino detector where the energy threshold is relatively higher, the large logarithmic effects induced by the scale hierarchy between the masses and momentum transfer are considered by introducing the DM parton distribution function (PDF). The logarithmic effects will reduce the electron recoil rate for DM scattering in neutrino detectors. Moreover, we find the DUNE and JUNO experiments provide high sensitivities for probing the dark photon component in the DM PDF through the dark Compton process. We also check the Bullet Cluster constraint on the DM self-scattering cross section.