Lifetime Measurements of Low-Lying States ofP33

Proton-$\gamma$ coincidence techniques have been used to measure, by the Doppler-shift attenuation method, the lifetimes of the nine bound states of ${}_{}{}^{33}{}_{}{}^{}\mathrm{P}$ below 4.3-MeV excitation energy, via the ${}_{}{}^{31}{}_{}{}^{}\mathrm{P}(t, p\gamma ){}_{}{}^{83}{}_{}{}^{}\mathrm{P}$ reaction, at triton bombarding energies of 2.5 and 3.1 MeV. More accurate excitation energies have also been obtained for these states. For the first nine excited states in ${}_{}{}^{33}{}_{}{}^{}\mathrm{P}$ the measurements lead to the following energies (keV) and lifetimes (psec): 1431.5±0.3 (0.60±0.10), 1847.3±0.3 (0.80±0.15), 2537.6±0.5 (0.070±0.012), 3275.5±1.0 (0.21±0.04), 3490.2±1.0 (0.11±0.02), 3626.6±1.0 (0.17±0.08), 4048±1 (0.085±0.030), 4194±3 (0.15±0.05), and 4225±1 (0.39±0.10). The decay modes and branching ratios for these states have also been measured. These results restrict the spin and parity of the listed states (MeV) to the following assignments $\left(J^{\pi }\right):3.28\mathrm{} (\frac{3}{2}, {\frac{5}{2}}^{+})$, $3.63 \left({\frac{7}{2}}^{+}\right)$, $4.05 \left({\frac{5}{2}}^{\mathrm{}(+)\mathrm{}}\right)$, $4.19 \left({\frac{5}{2}}^{+}\right)$. For some transitions better limits have been set on the $\delta$ mixing ratios previously measured. The ${}_{}{}^{33}{}_{}{}^{}\mathrm{P}$ spectrum obtained is compared to other results and to applicable shell-model calculations.