Microscopic description of the beta delayed deuteron emission from 6He.

Abstract

The beta delayed deuteron emission from $^{6}\mathrm{He}$ is studied in a dynamical microscopic cluster model. This model gives a reasonably good description for all the subsystems of $^{6}\mathrm{He}$ and $^{6}\mathrm{Li}$ in a coherent way, without any free parameter. The beta decay transition probability to the $^{6}\mathrm{Li}$ ground state is underestimated by a few percent. The theoretical beta delayed deuteron spectrum is close to experiment but it is also underestimated, by about a factor of 1.7. We argue that, in spite of their different magnitudes, both underestimations might have a common origin. The model confirms that the neutron halo part of the $^{6}\mathrm{He}$ wave function plays a crucial role in quenching the beta decay toward the \ensuremath{\alpha}+d channel.