Endothermic dark matter with a light dark photon and the LUX-ZEPLIN high-energy nuclear-recoil candidate

Pengxuan Zhu, Giovani Dalla Valle Garcia, Xuan-Gong Wang +2

The LUX-ZEPLIN (LZ) experiment has reported an inelastic nuclear-recoil candidate at $E_{\mathrm{nr}}=248\pm 23_{\mathrm{stat}}\pm 23_{\mathrm{sys}}\mathrm{keV}$. We test whether endothermic pseudo-…