Complete set of polarization transfer observables for the ${}^{16}{\rm O}(\vec{p},\vec{n}){}^{16}{\rm F}$ reaction at 296 MeV and 0 degrees

TL;DR

This study measures polarization transfer observables in the ${}^{16}{ m O}(oldsymbol{p},oldsymbol{n}){}^{16}{ m F}$ reaction at 296 MeV and compares results with shell-model calculations, revealing insights into Gamow-Teller and spin-dipole states.

Contribution

It provides a complete set of polarization transfer data for the ${}^{16}{ m O}(oldsymbol{p},oldsymbol{n}){}^{16}{ m F}$ reaction at 296 MeV and compares these with advanced shell-model calculations, highlighting specific nuclear states.

Findings

Reasonable reproduction of Gamow-Teller and spin-dipole states below 8 MeV.

Identification of a spin-longitudinal strength at 15 MeV indicating a $0^-$ SD resonance.

Observation of more $2^-$ strength than $1^-$ at 9.5 MeV.

Abstract

We report measurements of the cross section and a complete set of polarization transfer observables for the ${}^{16}{\rm O}(\vec{p},\vec{n}){}^{16}{\rm F}$ reaction at a bombarding energy of $T_p$ = 296 MeV and a reaction angle of $\theta_{\rm lab}$ = $0^{\circ}$. The data are compared with distorted-wave impulse approximation calculations employing the large configuration-space shell-model (SM) wave functions. The well-known Gamow-Teller and spin-dipole (SD) states at excitation energies of $E_x$ $\lesssim$ 8 MeV have been reasonably reproduced by the calculations except for the spin--parity $J^{\pi}$ = $2^-$ state at $E_x$ = 5.86 MeV. The SD resonance at $E_x$ $\simeq$ 9.5 MeV appears to have more $J^{\pi}$ = $2^-$ strength than $J^{\pi}$ = $1^-$ strength, consistent with the calculations. The data show significant strength in the spin-longitudinal polarized cross section $ID_L(0^{\circ})$ at $E_x$ $\simeq$ 15 MeV, which indicates existence of the $J^{\pi}$ = $0^-$ SD resonance as predicted in the SM calculations.