Experimental Study of theT=TzStates inZr90via a (He3,d) Reaction

Abstract

${}_{}{}^{89}{}_{}{}^{}\mathrm{Y}({}_{}{}^3{}_{}{}^{}\mathrm{He},d){}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}$ data taken with the Oak Ridge isochronous cyclotron with ${E^3}_{\mathrm{He}}=25\mathrm{}$ MeV are analyzed. 35 states are observed between 5.08- and 8.12-MeV excitation with $l_p=2\mathrm{}$ and $l_p=0\mathrm{}$. These states are considered to be the antianalog single-particle-hole states of the ${p_{\frac{1}{2}}}^{-1\mathrm{}}{d}_{\frac{5}{2}}$, ${p_{\frac{1}{2}}}^{-1\mathrm{}}{s}_{\frac{1}{2}}$, and ${p_{\frac{1}{2}}}^{-1\mathrm{}}{d}_{\frac{3}{2}}$ proton configuration in ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}$ mixed with "core-polarization" states. The possibility exists that there are some additional states of the ${p_{\frac{1}{2}}}^{-1\mathrm{}}{d}_{\frac{3}{2}}$ proton configuration higher than 8.12 MeV. The energy separation between the centroid of each of the $T_{<}=T_0-\frac{1}{2}$ groups and the corresponding analogs with $T_{>}=T_0+\frac{1}{2}$ is found to be approximately 7 MeV. The strength of the isobaric-spin-dependent potential, responsible for the splitting of the $T_{<}$ from the $T_{>}$ states, is calculated to be 148 MeV. Spectroscopic factors are extracted and are compared with theoretical sums of spectroscopic factors. The total number of $T_{<}$ states seen is in good agreement with the number calculated from considerations of core-polarization states mixed with the antianalog states through nuclear interactions.