New limits on neutrino magnetic moment through nonvanishing 13-mixing

Abstract

The relatively large value of the neutrino mixing angle θ 13 set by recent measurements allows us to use solar neutrinos to set a limit on the neutrino magnetic moment involving the second and third flavor families, μ 23 . The existence of a random magnetic field in the solar convective zone can produce a significant antineutrino flux when a nonvanishing neutrino magnetic moment is assumed. Even if we consider a vanishing neutrino magnetic moment involving the first family, electron antineutrinos are indirectly produced through the mixing between the first and third families and μ 23 ≠ 0. Using KamLAND limits on the solar flux of electron antineutrino, we set the limit μ 23 < 0.95 × 10 −11 μ B as a reasonable assumption on the behavior of solar magnetic fields. This is the first time that a limit on μ 23 has been established in the literature directly from neutrino interactions with magnetic fields, and, interestingly enough, is comparable with the limits on the neutrino magnetic moment involving the first family and with the ones coming from modifications to the electroweak cross section.

Probing neutrino transition magnetic moments with coherent elastic neutrino-nucleus scattering

“…To compare our results with current limits on TMMs, we analyze the recent solar neutrino data from Borexino phase-II [58] (see also Refs. [77][78][79]). In this case, the expression for the effective neutrino magnetic moment for solar neutrinos, in the mass basis is given by [49]…”

Constraining neutrino lifetimes and magnetic moments via solar neutrinos in the large xenon detectors

“…Finally, the GEMMA experiment [92] yields the limit µ eff 2.9 × 10 −11 µ B by observing the low-energy ER events caused by reactor neutrinos, and the future GEMMA-III project may improve the sensitivity to µ eff 9 × 10 −12 µ B by further lowering down the energy threshold and shortening the distance between the reactor and the detector [6]. The Borexino observation of low-energy solar neutrinos places a useful constraint on the neutrino magnetic moment [74,[93][94][95][96], while the most recent bound [74,93] has been updated with the Borexino-II data [97], namely, µ eff 10 −11 µ B at the 90% C.L. As is well known, neutrinos with lower energies will be advantageous in constraining neutrino lifetimes and magnetic moments, so the experiments for the direct detection of dark-matter particles are suitable for this task.…”

“…The Borexino observation of low-energy solar neutrinos places a useful constraint on the neutrino magnetic moment [74,[93][94][95][96], while the most recent bound [74,93] has been updated with the Borexino-II data [97], namely, µ eff 10 −11 µ B at the 90% C.L. As is well known, neutrinos with lower energies will be advantageous in constraining neutrino lifetimes and magnetic moments, so the experiments for the direct detection of dark-matter particles are suitable for this task.…”

Solar $$ {\overline{\nu}}_e $$ flux: revisiting bounds on neutrino magnetic moments and solar magnetic field

“…Although it is currently firmly established that the observed deficit of solar ν e is due to the MSW effect, SFP could still be present at a subdominant level. The combined action of neutrino SFP and flavour oscillations would then produce a small but potentially observable flux of solar electron antineutrinos νe at the Earth (see, e.g., [15,16] and references therein). The detection of such a flux would therefore be a clear signature of both nonzero magnetic moment and Majorana nature of neutrinos.…”