Search for neutrino radiative decay with a prototype Borexino detector

Search for neutrino radiative decay with a prototype Borexino detector
​A. V. Derbin & O. Ju. Smirnov
JETP Lett. Vol 76 No.7, 409-413 (2002).

Abstract

Results of background measurements with a prototype of the Borexino detector were used to obtain bounds on the lifetime of radiative neutrino decay ν_H→ν_L+γ. The new lower limit for the lifetime of pp and ⁷Be neutrinos is τ_c.m.(ν_H→ν_L+γ) /mν≥4.2×10³ s eV⁻¹(α)= 0). It is more than an order of magnitude stronger than the value obtained in previous experiments using nuclear reactors and accelerators.