Lifetimes of quasideuteron configurations in the odd-odd N=Z nucleus ₂₅⁵⁰Mn₂₅

Lifetimes and γγ coincidences for low-spin states of the odd-odd nucleus ⁵⁰Mn were measured in the ⁴⁰Ca(¹²C,np)⁵⁰Mn fusion-evaporation reaction at 27 MeV beam energy at the ESTU-tandem accelerator at Yale. The excitation energy of the J^π=5⁺ isomer is established for the first time from high-resolution γ-ray spectroscopy. Comparison to simulations of the Doppler-shift attenuation processes as functions of the level lifetimes enables us to extract lifetime information for five states. The measurement of B(M1) values agrees with the previous assignments of quasideuteron configurations in ⁵⁰Mn done on the basis of E2/M1-multipole mixing ratios and γ-branching ratios. The observations verify the predictions of an earlier full pf-shell model calculation for ⁵⁰Mn.