Interplay between nuclear chiral and reflection symmetry breakings revealed by the lifetime measurements in 76Br

Nearly degenerate positive-parity doublet bands and several E1 transitions between positive- and negative-parity bands have been identified in 76Br. These experimental observations are interpreted as the coexistence of chirality and octupole correlations, based on the analysis of detailed γ-ray spectroscopy with the precise lifetime measurements and theoretical calculations, and play a key role to explore the simultaneous breaking of chiral and reflection symmetry and their interplay. The present work provides the first test for chirality in the A≈80 mass region by lifetime measurements, and firstly elucidates the formation of chiral geometry in the presence of the octupole correlations in Br isotopes, leading to the conclusion that the reflection symmetry breaking catalyzes rather than destroys chiral symmetry breaking in nuclear systems.