The reaction rate of radiative n8Li capture in the range from 0.01 to 10 T9

Abstract

Within the modified potential cluster model (MPCM) with forbidden states, the total cross sections are calculated for capture in the ground and first excited states of the9Li nucleus in then8Li channel in the energy range from 10−5 eV to 5 MeV based onЕ1 andM1 transitions. The experimentally proved resonance atEc.m.= 0.232 MeV in the4P5/2wave andab initio-predicted4P3/2resonance at 1.32 MeV [Phys. Rev. C 103, 035801 (2021)] are considered. The strong impact of the asymptotic constant and channel spectroscopic factors on the total capture cross sections are responsible for the variation in the absolute values within factor two. As a consequence, the thermal cross sections areσtherm=24–46.8 mb. The evaluation ofσthermbased on the extrapolation ofab initiocross sections yields ∼85 mb. The reaction rate is calculated in the temperature range from 0.01 to 10T9. The reported reaction rates are compared at the benchmark point 1T9. The comparison of two datasets [Phys. Rev. C 103, 035801 (2021) and Phys. Rev. C 105, 064608 (2022)] on reaction rates recently calculated in microscopic models in extended temperature intervals shows the essential quantitative and qualitative differences. The comparative joint analysis of the reaction rates of radiative neutron capture on the lithium isotopes6,7,8Li is suggested for the choice of an optimal interval for the asymptotic constants.