Probing neutrino magnetic moment at the Jinping neutrino experiment

Abstract

Neutrino magnetic moment (νMM) is an important property of massive neutrinos. The recent anomalous excess at few keV electronic recoils observed by the XENON1T collaboration might indicate a ∼ 2.2 × 10−11μB effective neutrino magnetic moment ($$ {\mu}_{\nu}^{\mathrm{eff}} $$ μ ν eff ) from solar neutrinos. Therefore, it is essential to carry out the νMM searches at a different experiment to confirm or exclude such a hypothesis. We study the feasibility of doing νMM measurement with 4 kton fiducial mass at Jinping neutrino experiment (Jinping) using electron recoil data from both natural and artificial neutrino sources. The sensitivity of $$ {\mu}_{\nu}^{\mathrm{eff}} $$ μ ν eff can reach < 1.2 × 10−11μB at 90% C.L. with 10-year data taking of solar neutrinos. Besides the abundance of the intrinsic low energy background 14C and 85Kr in the liquid scintillator, we find the sensitivity to νMM is highly correlated with the systematic uncertainties of pp and 85Kr. Reducing systematic uncertainties (pp and 85Kr) and the intrinsic background (14C and 85Kr) can help to improve sensitivities below these levels and reach the region of astrophysical interest. With a 3 mega-Curie (MCi) artificial neutrino source 51Cr installed at Jinping neutrino detector for 55 days, it could give us a sensitivity to the electron neutrino magnetic moment ($$ {\mu}_{\nu_e} $$ μ ν e ) with < 1.1 × 10−11μB 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.

Enhancement of the screening effect in semiconductor detectors in the presence of the neutrino magnetic moment

“…In figure 2 we illustrate the constraints on the neutrino magnetic moment including the screening effect for different detector setups, with µ νe being the electron neutrino JHEP10(2023)021 magnetic moment and µ eff νµτ 0.49µ 2 νµ + 0.51µ 2 ντ being the effective parameter for µ and τ neutrinos [43]. We show the results based on different exposures of 10 kg•yr, 1 kg•yr and 0.2 kg•yr at 90% confidence level with two thresholds of 10 eV and 25 eV.…”

Solar Active-Sterile Neutrino Conversion with Atomic Effects at Dark Matter Direct Detection Experiments

“…While the SM neutrino interactions can only produce a flat event spectrum, a low energy peak arises if there is a BSM interaction with light mediator. Possible realizations include magnetic dipole moment, charge radius and anapole [3,[46][47][48][49][50][51][52][53][54], all with the massless photon as mediator. In addition, light scalar [55][56][57] and vector [55][56][57][58][59][60][61][62][63] mediators can also achieve the same purpose.…”