Speaker
Description
Cosmic rays in the Milky Way may collide with sub-GeV dark matter, imparting sufficient kinetic energies to produce detectable signals in liquid xenon
detectors. In this talk, I will present a new analysis on light dark matter accelerated by cosmic rays (CRDM) in the Milky Way, using data from the LUXZEPLIN (LZ) experiment, a dual-phase xenon detector located at the Sanford
Underground Research Facility in Lead, South Dakota, USA. This analysis uses
a total exposure of 4.2 tonne-years from two science runs, and features a novel
technique for tagging background events from Pb-214 decays. Several important factors have been introduced and examined, including the contributions of
heavier cosmic ray nuclei beyond protons and helium, as well as the non-uniform
distribution of cosmic rays and dark matter within the Milky Way. Darkprop,
a Monte Carlo simulation package, was utilized to account for Earth’s shielding
effects, incorporating the chemical composition and the nuclear form factors of
atoms in the Earth’s crust for CRDM propagation. Our preliminary results,
which establish the most stringent constraints on the spin-independent dark
matter–nucleon scattering cross section for CRDM models with masses between
100 keV and 1 GeV will be presented.
