Probing spin-isospin excitations in proton-rich nuclei via the C 11 (p,n) N 11 reaction

Tracking the evolution of nuclear properties away from stability serves as a valuable test for nuclear models. In the present work, the (p,n) charge-exchange reaction was used to test the extraction of β- Gamow-Teller transition strengths, B(GT), from proton-rich unstable isotopes, and the resulting B(GT) values were compared to shell-model and ab initio calculations. The C11(p,n)N11 reaction was measured in inverse kinematics at 95 MeV/u at the National Superconducting Cyclotron Laboratory. The B(GT) values to the 12- state at 0.73 MeV and the 32- state at 2.86 MeV in N11 were determined to be 0.18(1)stat(3)sys and 0.18(1)stat(4)sys, respectively. These results are consistent with shell-model calculations using the wbp interaction after introducing a phenomenological quenching factor and with ab initio variational Monte Carlo calculations using the NV2+3Ia∗ NN and 3N interactions without any scaling. Additionally, this result is consistent with the B(GT) values extracted from mirror B11(n,p) and B11(t,He3) reactions. This experiment demonstrates the feasibility of using the (p,n) probe in inverse kinematics to extract B(GT) from proton-rich nuclei, although improved background suppression will be important in future experiments.