Astrophysical factor for the radiative capture reaction alpha+d->Li-6+gamma

Abstract

We consider the radiative capture process alpha+d-->Li-6+gamma at energies, E(c.m.)less than or equal to 300 keV, that are relevant for astrophysical processes. Due to the peripheral character of the reaction, the overall normalization of the astrophysical factor S-24 is entirely governed by one quantity, the asymptotic normalization coefficient C-01 for Li-6-->alpha+d. Using the recently well established value for this constant C-01=2.3+/-0.12 fm(-1/2), we calculated S-24 taking into account both E1 and E2 contributions. Our recommended value for S-24 is 2.57 MeV nb at the most effective energy for the capture reaction in astrophysical processes, E(c.m.)=70 keV, which gives a reaction rate 0.036 cm(3) mole(-1) s(-1) at the temperature 0.8x10(9) K. We found a significant energy dependence of S-24 at astrophysical energies. At energies of less than 110 keV, the E1 component dominates over the E2 component. AtE(c.m.)=70 keV, the E1 contribution to the total transition is about 58%.