Chiral Effective Field Theory Calculations of Weak Transitions in Light Nuclei
Abstract
We report Quantum Monte Carlo calculations of weak transitions in nuclei, based on the Norfolk two- and three-nucleon chiral interactions, and associated one- and two-body axial currents. We find that the contribution from two-body currents is at the - level, with the exception of matrix elements entering the rates of Li, B, and He beta decays. These matrix elements are suppressed in impulse approximation based on the (leading order) Gamow Teller transition operator alone; two-body currents provide a - correction, which is, however, insufficient to bring theory in agreement with experimental data. For the other transitions, the agreement with the data is satisfactory, and the results exhibit a negligible to mild model dependence when different combinations of Norfolk interactions are utilized to construct the nuclear wave functions. We report a complete study of two-body weak transition densities which reveals the expected universal behavior of two-body currents at short distances throughout the range of = to = systems considered here.
Keywords
Cite
@article{arxiv.2004.05263,
title = {Chiral Effective Field Theory Calculations of Weak Transitions in Light Nuclei},
author = {G. B. King and L. Andreoli and S. Pastore and M. Piarulli and R. Schiavilla and R. B. Wiringa and J. Carlson and S. Gandolfi},
journal= {arXiv preprint arXiv:2004.05263},
year = {2020}
}
Comments
14 pages, 9 figures; Corrected experimental values for $^8$Li beta decay in Table V to be consistent with Table VI and the text; Corrected an error in row 2 column 4 of Figure 6, conclusions unchanged; Corrected errors in column 3 rows 3 and 4 of Figure 7, results unchanged; Corrected a typo in Equation 19, results in tables unchanged; Corrected $^8$He ground state isospin from $T=1$ to $T=2$