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

Artikel i vetenskaplig tidskrift, 2020

The low-energy behavior of the strength function for the 1− soft dipole excitation in 6He 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 α+n+n→6He+γ is calculated. Comparison with the previous calculations is performed.