Probing neutrino magnetic moment at the Jinping neutrino experiment

Abstract

Neutrino magnetic moment ($\nu$MM) is an important property of massive neutrinos. The recent anomalous excess at few keV electronic recoils observed by the Xenon1T collaboration might indicate a $\sim 2.2\times10^{-11} \mu_B$ effective neutrino magnetic moment ($\mu_\nu^{eff}$) from solar neutrinos. Therefore, it is essential to carry out the $\nu$MM searches at a different experiment to confirm or exclude such hypothesis. We study the feasibility of doing $\nu$MM measurement with 4 kton active mass at Jinping neutrino experiment using electron recoil data from both natural and artificial neutrino sources. The sensitivity of $\mu_\nu^{eff}$ can reach $1.2\times10^{-11}\mu_B$ at 90\% C.L. with 10-year data taking of solar neutrinos. Besides the intrinsic low energy background $^{14}$C in the liquid scintillator, we find the sensitivity to $\nu$MM is highly correlated with the systematic uncertainties of $pp$ and $^{85}$Kr. Reducing systematic uncertainties ($pp$ and $^{85}$Kr) and the intrinsic background ($^{14}$C and $^{85}$Kr) can help to improve sensitivities below these levels and reach the region of astrophysical interest. With a 3 mega-Curie (MCi) artificial neutrino source $^{51}$Cr installed at Jinping neutrino detector for 55 days, it could give us a sensitivity to the electron neutrino magnetic moment ($\mu_{\nu_e}$) with $1.1\times10^{-11} \mu_B$ at 90\% C.L.. With the combination of those two measurements, the flavor structure of the neutrino magnetic moment can be also probed at Jinping.