Lifetime measurements in 80Br and a new region for observation of chiral electromagnetic selection rule

Level lifetimes for the candidate chiral doublet bands of 80 Br were extracted by means of the Doppler-shift attenuation method. The absolute transition probabilities derived from the lifetimes agree well with the M 1 and E2 chiral electromagnetic selection rules, and the calculations reported in the frame- work of triaxial particle rotor model [S.Y. Wang et al., Phys. Lett. B 703 (2011) 40] also support firmly for the chirality in 80 Br. Such good agree- ments among the experimental data, selection rules of chiral doublet bands and theoretical calculations are rare and outstanding in researches of nuclear chirality. Besides odd-odd Cs isotopes, odd-odd Br isotopes in the A ≈ 80 mass region represent another territory that exhibits the ideal selection rules expected for chiral doublet bands.