Three-body vs. dineutron approach to two-neutron radiative capture in He-6

摘要

The low-energy behavior of the strength function for the 1(-) soft dipole excitation in He-6 is studied theoretically. Use of very large basis sizes and well-grounded extrapolation procedures allows to move to energies as small as 1 keV, at which the low-energy asymptotic behavior of the E1 strength function seems to be achieved. It is found that the low-energy behavior of the strength function is well described in the effective three-body "dynamical dineutron model". The astrophysical rate for the alpha+n+n -> He-6+gamma is calculated. Comparison with the previous calculations is performed. (C) 2020 The Author(s). Published by Elsevier B.V.