Cross Section of Solar Neutrino Capture by 76Ge Nuclei

Abstract

The results are presented from calculating capture cross section σ(E_ν) of solar neutrinos by ⁷⁶Ge nuclei. Experimental data on strength function S(E), obtained in the charge-exchange ⁷⁶Ge(³He, t)⁷⁶As reaction, are used in these calculations. The effect the resonance structure of strength function S(E) has on cross section σ(E_ν) is examined. It is shown that the giant Gamow–Teller resonance alone makes a contribution of ~20%, and the contribution of lower-lying excitations in the continuous spectrum part is even larger. These contributions must be considered in calculations for background events in experiments on double beta decay of the GERDA (LEGEND) type.