Gamma-ray spectroscopy of low-lying states inCr56

Nuclear properties of the excited states below 3.2 MeV in ${}_{}{}^{56}{}_{}{}^{}\mathrm{Cr}$ were studied in the ${}_{}{}^{54}{}_{}{}^{}\mathrm{Cr}(t,p\gamma ){}_{}{}^{56}{}_{}{}^{}\mathrm{Cr}$ reaction at $E_t=2.9\mathrm{}$ MeV. Reaction-produced protons were detected at 171°±4° to the beam in coincidence with $\gamma$ rays. $\gamma$-ray angular correlations and branching ratios were measured using an array of five NaI(Tl) crystals, while $\gamma$-ray energies and lifetime limits were obtained using a Ge(Li) detector. Spin assignments for some of the excited states were obtained in addition to multipole mixing-ratio information. The results for the excitation energies (keV), spins, and lifetimes (psec) are: 1007.6±1.5,2,≥2; 1832.2 ± 2.6,2, undetermined; 2327.8±2.6,2,≤0.08; 2687±13,1,2,3, or 4, undetermined; 3165.6 ± 6.2, 2, 3, or 4, ≤ 0.3. The results are compared with shell-model calculations.