Variational Monte Carlo calculations of the 2H(d,γ) 4He reaction at low energies

Abstract

The 2H(d,γ) 4He reaction is studied at center of mass energies below 500 KeV, where it is dominated by the E2 transition from the 5S 2 continuum state to the ground state of the α-particle. Both the 5S 2 continuum and the ground states are calculated with the Variational Monte Carlo method using the realistic Argonne- v 14 two-nucleon and Urbana model- VII three-nucleon interactions. This reaction can proceed only through the D-states in the deuteron and/or in the α-particle. It is found that, depending upon the continuum wave function, the contributions of the deuteron and α-particle D-states can either add to produce a large cross section, or cancel. The reaction is thus very sensitive to the continuum wave function. It is also found that the wave function that minimizes the energy in the scattering calculation, is not the one that gives the best results for the capture reaction cross section.