n + n + α → 6He + γ reaction by effective field theory approach

The astrophysics reaction n + n + alpha -> He-6 + gamma is studied by the effective field theory approach. For this purpose, as a first step, we introduce the Faddeev equation of the particle-dimer scattering amplitudes in the 2 x 2 cluster configuration space using the formalism based on the halo effective field theory in the channel J(pi) = 1(-). In the next step, the normalized He-6 wave function is obtained by solving the homogenous part of the particle-dimer scattering amplitudes in the channel J(pi) = 0(+). Then the electric dipole transition amplitude of reaction n + n + alpha -> He-6 + gamma is calculated using the particle-dimer scattering amplitudes and the He-6 wave function. Finally, we report our results for the electric dipole strength function distribution of the He-6 halo nucleus at the leading order and compare them with experimental data and other theoretical results.