6He beta-decay rate and the suppression of the axial constant in nuclear matter

Abstract

We present a microscopic calculation of the 6He beta-decay into the ground state of 6Li. To this end, we use chiral perturbation theory at next-to-next-to-next-to-leading order to describe the nuclear weak-currents. The nuclear wave functions are derived from the J-matrix inverse scattering nucleon-nucleon potential (JISP), and the Schroedinger equation is solved using the hyperspherical-harmonics expansion. Our calculation brings the theoretical decay-rate within 3% of the measured one. This success is attributed to the use of chiral-perturbation-theory based mesonic currents, whose contribution is qualitatively different compared to standard nuclear physics approach, where the use of meson exchange currents worsens the comparison to experiment. The inherent inconsistency in the use of the JISP potential together with chiral-perturbation-theory based is argued not to affect this conclusion, though a more detailed investigation is called for. We conclude that any suppression of the axial constant in nuclear matter is included in this description of the weak interaction in the nucleus.

Accepted for publication in Physical Review C

References in corpus (2)

• Quantum Monte Carlo calculations of electroweak transition matrix elements in A = 6,7 nuclei
• Test of J-matrix inverse scattering potentials on electromagnetic reactions of few-nucleon systems

Cited by in corpus (5)

• Three-body forces: From cold atoms to nuclei
• Effects of three-nucleon forces and two-body currents on Gamow-Teller strengths
• Calculation of the ${}^6$Li ground state within the hyperspherical harmonic basis
• Muon capture on deuteron and 3He
• Comparative study of ${}^6$He $\beta$-decay based on different similarity-renormalization-group evolved chiral interactions