Microscopic calculation of the 3He(alpha,gamma)7Be and 3H(alpha,gamma)7Li capture cross sections using realistic interactions

TL;DR

This paper presents a microscopic calculation of the radiative capture cross sections for 3He(alpha,gamma)7Be and 3H(alpha,gamma)7Li reactions using a realistic interaction within a fermionic molecular dynamics framework, achieving good agreement with experimental data for 3He and highlighting discrepancies for 3H.

Contribution

It introduces a fully microscopic fermionic molecular dynamics approach with realistic interactions to accurately compute capture cross sections for these reactions, extending the many-body wave functions at short distances.

Findings

Calculated S factor for 3He(alpha,gamma)7Be matches experimental data well.

Calculated S factor for 3H(alpha,gamma)7Li exceeds experimental data by about 15%.

Properties of bound states and phase shifts are well described.

Abstract

The radiative capture cross sections for the 3He(alpha,gamma)7Be and 3H(alpha,gamma)7Li reactions are calculated in the fully microscopic fermionic molecular dynamics approach using a realistic effective interaction that reproduces the nucleon-nucleon scattering data. At large distances bound and scattering states are described by antisymmetrized products of 4He and 3He/3H ground states. At short distances the many-body Hilbert space is extended with additional many-body wave functions needed to represent polarized clusters and shell-model-like configurations. Properties of the bound states are described well, as are the scattering phase shifts. The calculated S factor for the 3He(alpha,gamma)7Be reaction agrees very well with recent experimental data both in absolute normalization and energy dependence. In case of the 3H(alpha,gamma)7Li reaction the calculated S factor is larger than available experimental data by about 15%.