The 76Se Gamow–Teller strength distribution and its importance for stellar electron capture rates

Recent theoretical studies predicted that, due to nuclear correlations across the N=40 shell gap, electron captures on nuclei with proton numbers Z<40 and neutron numbers N>40 would not be strongly suppressed due to Pauli blocking of Gamow–Teller (GT) transitions. This prediction has recently been confirmed by the experimental determination of the single-particle occupation numbers in 76Se and by the measurement of the 76Se GT+ strength distribution. In this manuscript we derive such occupation numbers and GT+ distributions within large-scale shell model studies. Based on the same models, we calculate stellar electron capture rates and compare them to those obtained from the experimental GT+ data.