The Results of Search for the Neutrino Magnetic Moment in GEMMA Experiment

Abstract

The result of the neutrino magnetic moment measurement at the Kalinin Nuclear Power Plant (KNPP) with GEMMA spectrometer is presented. The antineutrino-electron scattering is investigated. A high-purity germanium detector with a mass of 1.5 kg placed at a distance of 13.9 m from the 3 GWthreactor core is exposed to the antineutrino flux of2.7×10131/cm2/s. The recoil electron spectra taken in 18134 and 4487 hours for the reactor ON and OFF periods are compared. The upper limit for the neutrino magnetic momentμν< 2.9×10−11μBat 90% C.L. is derived from the data processing.

Plasmon Decay to a Neutrino Pair via Neutrino Electromagnetic Moments in a Strongly Magnetized Medium

“…(7) givesμ ν < 5.1 × 10 −11 , which is close to the bounds µ ν < 5.4 × 10 −11 µ B and µν e < 2.9 × 10 −11 µ B that were obtained from the analysis of solar neutrinos [10] and in the GEMMA laboratory experiment on antineutrino scattering off electrons [11], respectively.…”

New limits on neutrino magnetic moment through nonvanishing 13-mixing

“…Also, solar neutrino experiments obtained a limit on the neutrino magnetic moment coming from modifications of the neutrino electroweak cross section. For instance, the GEMMA experiment [14]-which uses a reactor antineutrino flux and analyzes the recoil electron spectra produced from the detection of such an antineutrino flux-has established the limit μ ν < 2.9 × 10 −11 μ B . The experiments Super-Kamiokande [15] and Borexino [16] obtained limits of μ ν < 1.1 × 10 −10 μ B and μ ν < 5.4 × 10 −11 μ B , respectively, by analyzing the spectrum of the solar neutrino flux, which applies for a combination of all neutrino magnetic moment elements.…”

Revisiting large neutrino magnetic moments

“…The best current laboratory limit is given by GEMMA, an experiment measuring the electron recoil of antineutrino-electron scattering near the reactor core. It constrains the effective magnetic moment to be less than 2.9 · 10 −11 µ B [7]. A recent study by Cañas et al [8] showed that results of the solar neutrino experiment Borexino give similar limits.…”

“…(2.2) and (2.3). The current best laboratory experimental limit for the NMM is at µ ν ∼ 2.9·10 −11 µ B [7], while neutrino masses above 0.2 eV are in conflict with cosmological observations [9]. Therefore the above estimate shows that generating large NMM while simultaneously keeping the radiative mass correction δm ν low, requires a significant amount of fine-tuning.…”