Effects of Three-Nucleon Forces and Two-Body Currents on Gamow-Teller Strengths

A. Ekström, G. R. Jansen, K. A. Wendt, G. Hagen, T. Papenbrock, S. Bacca, B. Carlsson, and D. Gazit

Phys. Rev. Lett. 113, 262504 – Published 30 December 2014

Abstract

We optimize chiral interactions at next-to-next-to leading order to observables in two- and three-nucleon systems and compute Gamow-Teller transitions in ${}^{14}C$ and ${}^{22, 24}O$ using consistent two-body currents. We compute spectra of the daughter nuclei ${}^{14}N$ and ${}^{22, 24}F$ via an isospin-breaking coupled-cluster technique, with several predictions. The two-body currents reduce the Ikeda sum rule, corresponding to a quenching factor $q^{2} \approx 0.84 - 0.92$ of the axial-vector coupling. The half-life of ${}^{14}C$ depends on the energy of the first excited $1^{+}$ state, the three-nucleon force, and the two-body current.

Received 18 June 2014

DOI:https://doi.org/10.1103/PhysRevLett.113.262504

Authors & Affiliations

A. Ekström¹, G. R. Jansen^2,3, K. A. Wendt^3,2, G. Hagen^2,3, T. Papenbrock^3,2, S. Bacca^4,5, B. Carlsson⁶, and D. Gazit⁷

¹Department of Physics and Center of Mathematics for Applications, University of Oslo, N-0316 Oslo, Norway
²Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
³Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
⁴TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
⁵Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
⁶Department of Fundamental Physics, Chalmers University of Technology, SE-412 96 Göteborg, Sweden
⁷Racah Institute of Physics, Hebrew University, 91904 Jerusalem, Israel