VARIATIONAL MONTE-CARLO CALCULATIONS OF THE H-2 (D,GAMMA)HE4 REACTION AT LOW ENERGIES

The H-2(d,gamma)He-4 reaction is studied at center-of-mass energies below 500 keV, where it is dominated by the E2 transition from the S5(2) continuum state to the ground state of the alpha particle. Both the S5(2) continuum and the ground states are calculated with the variational Monte Carlo method using the realistic Argonne-nu-14 two-nucleon and Urbana model-VII three-nucleon interactions. A qualitative agreement with the observed cross section is obtained. This reaction can proceed only through the D states in the deuteron and/or in the alpha particle. It is found that, depending upon the continuum wave function, the contributions of the deuteron and alpha-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.