Particle-hole strength excited in theCa40(p,n)40Sc reaction at 134 MeV

The ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$(p,n${)}^{40}$Sc reaction was studied at 134 MeV. Neutron energy spectra were measured by the time-of-flight technique with resolutions of 220 keV at angles from 0° to 41° and 415 keV out to 62°. The $2^{\mathrm{-}}$,$3^{\mathrm{-}}$,$4^{\mathrm{-}}$,$5^{\mathrm{-}}$ band of states based on the ($f_{7/2}$,$d_{3/2}^{\mathrm{-}1}$) 1p1h structure was observed at low excitation energies, in good agreement with known analog states in ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ and ${}_{}{}^{40}{}_{}{}^{}\mathrm{K}$. The shapes of the cross-section and analyzing-power angular distributions are in good agreement with distorted-wave impulse-approximation calculations using simple 1p1h (Tamm-Dancoff approximation) shell-model wave functions. A relatively strong transition to a state at $E_x$=2.3 MeV with L=3 is identified tentatively as a $4^{\mathrm{-}}$ state with the predominant 1p1h structure (1$f_{7/2}$,2$s_{1/2}^{\mathrm{-}1}$).