Low-lying dipole strength in Cr52

Abstract

The low-lying dipole strength in $^{52}\mathrm{Cr}$ was measured in nuclear resonance fluorescence experiments using a quasimonochromatic, linearly polarized photon beam. The parities of the excited dipole states were determined by the intensity asymmetry of resonantly scattered $\ensuremath{\gamma}$ rays with respect to the polarization plane of the incident photon beam. We observed 62 resonances at excitation energies between 7.5 and 12.1 MeV. The observed $M1$ and $E1$ strengths were compared via random-phase-approximation calculations using the Skyrme interaction. The effects of two-particle--two-hole configuration mixing and tensor force on dipole strength distributions were investigated.