Probing spin-isospin excitations in proton-rich nuclei via theC11(p,n)N11reaction

Abstract

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 ${\ensuremath{\beta}}^{\ensuremath{-}}$ Gamow-Teller transition strengths, $B(\mathrm{GT})$, from proton-rich unstable isotopes, and the resulting $B(\mathrm{GT})$ values were compared to shell-model and ab initio calculations. The $^{11}\mathrm{C}(p,n)^{11}\mathrm{N}$ reaction was measured in inverse kinematics at 95 MeV/u at the National Superconducting Cyclotron Laboratory. The $B(\mathrm{GT})$ values to the ${\frac{1}{2}}^{\ensuremath{-}}$ state at 0.73 MeV and the ${\frac{3}{2}}^{\ensuremath{-}}$ state at 2.86 MeV in $^{11}\mathrm{N}$ were determined to be $0.18{(1)}^{\mathrm{stat}}{(3)}^{\mathrm{sys}}$ and $0.18{(1)}^{\mathrm{stat}}{(4)}^{\mathrm{sys}}$, 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 $NV2+3I{a}^{*}$ $NN$ and $3N$ interactions without any scaling. Additionally, this result is consistent with the $B(\mathrm{GT})$ values extracted from mirror $^{11}\mathrm{B}(n,p)$ and $^{11}\mathrm{B}(t,^{3}\mathrm{He})$ reactions. This experiment demonstrates the feasibility of using the $(p,n)$ probe in inverse kinematics to extract $B(\mathrm{GT})$ from proton-rich nuclei, although improved background suppression will be important in future experiments.