Unambiguously Resolving the Potential Neutrino Magnetic Moment Signal at Large Liquid Scintillator Detectors

Non-vanishing electromagnetic properties of neutrinos have been predicted by many theories beyond the Standard Model, and an enhanced neutrino magnetic moment can have profound implications for fundamental physics. The XENON1T experiment recently detected an excess of electron recoil events in the 1–7 keV energy range, which can be compatible with solar neutrino magnetic moment interaction at a most probable value of μν = 2.1 × 10−11 μ B. However, tritium backgrounds or solar axion interaction in this energy window are equally plausible causes. Upcoming multi-tonne noble liquid detectors will test these scenarios more in depth, but will continue to face similar ambiguity. We report a unique capability of future large liquid scintillator detectors to help resolve the potential neutrino magnetic moment scenario. With O(100) kton⋅year exposure of liquid scintillator to solar neutrinos, a sensitivity of μν < 10−11 μ B can be reached at an energy threshold greater than 40 keV, where no tritium or solar axion events but only neutrino magnetic moment signal is still present.

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Probing neutrino magnetic moment at the Jinping neutrino experiment

Journal of High Energy Physics ◽

10.1007/jhep08(2021)068 ◽

2021 ◽

Vol 2021 (8) ◽

Author(s):

Baobiao Yue ◽

Jiajun Liao ◽

Jiajie Ling

Keyword(s):

Magnetic Moment ◽

Liquid Scintillator ◽

Solar Neutrinos ◽

Electron Neutrino ◽

Neutrino Experiment ◽

Neutrino Magnetic Moment ◽

Systematic Uncertainties ◽

Electron Recoil ◽

Massive Neutrinos ◽

Highly Correlated

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.

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Limits on the Neutrino Magnetic Moment Using Super-Kamiokande Solar Neutrino Data

International Journal of Modern Physics A ◽

10.1142/s0217751x05025875 ◽

2005 ◽

Vol 20 (14) ◽

pp. 3110-3112 ◽

Cited By ~ 3

Author(s):

◽

D. W. Liu

Keyword(s):

Energy Spectrum ◽

Magnetic Moment ◽

Solar Neutrino ◽

New Physics ◽

Beyond The Standard Model ◽

High Statistic ◽

Neutrino Magnetic Moment ◽

The Standard Model ◽

Neutrino Experiments ◽

Event Rates

Existence of non-zero neutrino magnetic moment would mean new physics beyond the standard model. A search for the neutrino magnetic moment has been conducted using the high statistic solar neutrino data from Super-Kamiokande-I. This is done by looking for the distortion to the observed energy spectrum of recoil electrons. A non-zero neutrino magnetic moment would cause an increase of event rates at lower energies. The search found no clear signal of neutrino magnetic moment. A limit on the neutrino magnetic moment has been obtained at 3.6 × 10-10μB at 90% C.L. by fitting to the Super-Kamiokande day-night spectra. The effects of neutrino oscillation have been included in the analysis. Including results from other neutrino experiments limiting the oscillation region, a limit of 1.1 × 10-10μB at 90% C.L. was obtained.

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