Neutrino mass and mixing: the impact of excited state contributions on capture rates of Ga detectors

Abstract

In this paper we calculate the neutrino absorption cross-sections for the reaction ⁷¹Ga(ν , e−)⁷¹Ge using two simple nuclear models to account for the giant GT resonances. In both models the excited state contributions are found to have significant ranges of variation and affect the solar neutrino capture rates. Nonetheless, the regions in the neutrino mixing angle-mass squared difference plane allowed by the data from the Gallium detectors, when taken together with those from the Chlorine and Kamioka experiments, are found to be comparatively stable.