Polarization transfer in the ${}^{16}$O$(p,p^{\prime })$ reaction at forward angles and structure of the spin-dipole resonances

Abstract

Cross sections and polarization transfer observables in the ${}^{16}$O$(p,p^{\prime })$ reactions at 392 MeV were measured at several angles between $\hat{I}{¸}_{lab}=$ 0${}^{\circ }$ and 14${}^{\circ }$. The non-spin-flip ($\hat{I}”S=0$) and spin-flip ($\hat{I}”S=1$) strengths in transitions to several discrete states and broad resonances in ${}^{16}$O were extracted using a model-independent method. The giant resonances in the energy region of $E_x=19-$27 MeV were found to be predominantly excited by $\hat{I}”L=1$ transitions. The strength distribution of spin-dipole transitions with $\hat{I}”S=1$ and $\hat{I}”L=1$ were deduced. The obtained distribution was compared with a recent shell model calculation. Experimental results are reasonably explained by distorted-wave impulse approximation calculations with the shell model wave functions.

28 pages RevTex, including 9 figures, to be published in Phys. Rev. C.; a typo in Eq. (3b) was corrected