Complete sets of polarization transfer observables for the208Pb(p⃗,n⃗)reaction at 296 MeV and Gamow-Teller and spin-dipole strengths for208Pb

Abstract

We report measurements of cross sections and analyzing powers for reaction angles of ${\ensuremath{\theta}}_{\mathrm{lab}}={0.0}^{\ensuremath{\circ}}$--${10.0}^{\ensuremath{\circ}}$ and complete sets of polarization transfer observables and induced polarizations at ${\ensuremath{\theta}}_{\mathrm{lab}}={0.0}^{\ensuremath{\circ}}$--${7.0}^{\ensuremath{\circ}}$ for the ${}^{208}\mathrm{Pb}(\stackrel{P\vec}{p},\stackrel{P\vec}{n})$ reaction at a bombarding energy of ${T}_{p}=296$ MeV. A multipole decomposition technique was applied to the data to extract the Gamow-Teller (GT) and spin-dipole (SD) components from the continuum. The polarization observables were also used, for the first time, to separate the SD components into different spin-parity transfer ($\ensuremath{\Delta}{J}^{\ensuremath{\pi}}={0}^{\ensuremath{-}}$, ${1}^{\ensuremath{-}}$, and ${2}^{\ensuremath{-}}$) contributions. A significant strength with $\ensuremath{\Delta}{J}^{\ensuremath{\pi}}={1}^{+}$ is identified in the continuum beyond the GT giant resonance, which is due to configuration mixing effects and the isovector spin monopole (IVSM) contribution. The SD strength distributions were clearly dependent on $\ensuremath{\Delta}{J}^{\ensuremath{\pi}}$, which is reasonably reproduced by Hartree-Fock (HF) plus random phase approximation (RPA) calculations that include the Skyrme interaction with tensor components [Phys. Rev. C 83, 054316 (2011)].