Inelastic $B-L$ scalar dark matter and the LUX-ZEPLIN event

Abstract

We show that our previously proposed inelastic scalar dark matter (DM) model in gauged $U(1{)}_{B-L}$ symmetry naturally accounts for the $2.6\sigma$ high-energy recoil event recently reported by the LUX-ZEPLIN (LZ) collaboration. To satisfy the thermal relic abundance, TeV-scale scalar DM $S$ with $m_S\simeq m_{Z^{\prime }}/2$ for resonant annihilation and the gauge coupling constant $g_{B-L}\sim 0.5$ are required, where $m_{Z^{\prime }}$ is the mass of $U(1{)}_{B-L}$ gauge boson $Z^{\prime }$. The resulting predicted DM-nucleon inelastic cross section of ${\sigma }_{\mathrm{SI}}\sim 10^{-45}$ cm${}^2$ is in excellent agreement with the LZ event. This scenario can be decisively tested for future collider searches for $Z^{\prime }$ boson resonance.

Comments: 9 pages, 2 figures