Search for exotic interactions of solar neutrinos in the CDEX-10 experiment

Abstract

We investigate exotic neutrino interactions using the $205.4\text{\ensuremath{-}}\mathrm{kg}\ifmmode\cdot\else\textperiodcentered\fi{}\mathrm{day}$ dataset from the CDEX-10 experiment at the China Jinping Underground Laboratory. New constraints on the mass and couplings of new gauge bosons are presented. Two nonstandard neutrino interactions are considered: a $U(1{)}_{\mathrm{B}--\mathrm{L}}$ gauge-boson-induced interaction between an active neutrino and electron/nucleus, and a dark-photon-induced interaction between a sterile neutrino and electron/nucleus via kinetic mixing with a photon. This work probes an unexplored parameter space involving sterile neutrino coupling with a dark photon. New laboratory limits are derived on dark photon masses below $1\text{ }\text{ }\mathrm{eV}/{c}^{2}$ at some benchmark values of $\mathrm{\ensuremath{\Delta}}{m}_{41}^{2}$ and ${g}^{\ensuremath{'}2}{\mathrm{sin}}^{2}2{\ensuremath{\theta}}_{14}$.