Search for solar electron anti-neutrinos due to spin-flavor precession in the Sun with Super-Kamiokande-IV

Abstract

Due to a very low production rate of electron anti-neutrinos (${\bar{\nu }}_e$) via nuclear fusion in the Sun, a flux of solar ${\bar{\nu }}_e$ is unexpected. An appearance of ${\bar{\nu }}_e$ in solar neutrino flux opens a new window for the new physics beyond the standard model. In particular, a spin-flavor precession process is expected to convert an electron neutrino into an electron anti-neutrino (${\nu }_e\to {\bar{\nu }}_e$) when neutrino has a finite magnetic moment. In this work, we have searched for solar ${\bar{\nu }}_e$ in the Super-Kamiokande experiment, using neutron tagging to identify their inverse beta decay signature. We identified 78 ${\bar{\nu }}_e$ candidates for neutrino energies of 9.3 to 17.3 MeV in 2970.1 live days with a fiducial volume of 22.5 kiloton water (183.0 kton$\cdot$year exposure). The energy spectrum has been consistent with background predictions and we thus derived a 90% confidence level upper limit of $4.7\times 10^{-4}$ on the ${\nu }_e\to {\bar{\nu }}_e$ conversion probability in the Sun. We used this result to evaluate the sensitivity of future experiments, notably the Super-Kamiokande Gadolinium (SK-Gd) upgrade.

16 pages, 10 figures, 7 tables

References in corpus (3)

• Solar neutrino measurements in Super-Kamiokande-II
• A new parameterization of the nucleon elastic form factors
• Improvement of low energy atmospheric neutrino flux calculation using the JAM nuclear interaction model

Cited by in corpus (7)

• Search for astrophysical electron antineutrinos in Super-Kamiokande with 0.01wt% gadolinium-loaded water
• Solar neutrino physics
• Shedding light on neutrino self-interactions with solar antineutrino searches
• Diffuse Neutrino Background from Magnetorotational Stellar Core Collapses
• PEANUTS: a software for the automatic computation of solar neutrino flux and its propagation within Earth
• Implications of MicroBooNE's low sensitivity to electron antineutrino interactions in the search for the MiniBooNE excess
• Estimating JUNO's Sensitivity to Solar Neutrino-to-antineutrino Conversion and Neutrino Magnetic Moments