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Six-body calculation of the alpha-deuteron radiative capture cross section

K. M. Nollett·R. B. Wiringa·R. Schiavilla
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Abstract

We have computed the cross section for the process d + alpha -> 6Li + gamma at the low energies relevant for primordial nucleosynthesis and comparison with laboratory data. The final state is a six-body wave function generated by the variational Monte Carlo method from the Argonne v_18 and Urbana IX potentials, including improved treatment of large-particle-separation behavior. The initial state is built up from the alpha-particle and deuteron ground-state solutions for these potentials, with phenomenological descriptions of scattering and cluster distortions. The dominant E2 cross section is in reasonable agreement with the laboratory data. Including center-of-energy and other small corrections, we obtain an E1 contribution which is larger than the measured contribution at 2 MeV by a factor of 7. We calculate explicitly the impulse-approximation M1 contribution, which is expected to be very small, and obtain a result consistent with zero. We find little reason to suspect that the cross section is large enough to produce significant 6Li in the big bang.

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K. M. Nollett, R. B. Wiringa, R. Schiavilla. 2000-12-31. Six-body calculation of the alpha-deuteron radiative capture cross section. https://doi.org/10.1103/physrevc.63.024003

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