Evolution of chirality from transverse wobbling in ${}^{135}$Pr

Abstract

Chirality is a distinct signature that characterizes triaxial shapes in nuclei. We report the first observation of chirality in the nucleus ${}^{135}$Pr using a high-statistics Gammasphere experiment with the ${}^{123}$Sb(${}^{16}$O,4n)${}^{135}$Pr reaction. Two chiral-partner bands with the configuration $\ddot{I}€(1h_{11/2}{)}^1\otimes \hat{I}½(1h_{11/2}{)}^{-2}$ have been identified in this nucleus. Angular distribution analyses of the $\hat{I}”I=1$ transitions connecting the two bands reveal a dominant dipole character, and quasiparticle triaxial rotor model calculations show good agreement with the data. Since the simultaneous observation of chirality and transverse wobbling in ${}^{135}$Pr relies critically on these angular distribution results, we also address and refute the experimental and theoretical criticisms raised in a recent work by Lv et al., presenting additional evidence that further strengthens our interpretation. This marks the first observation of both hallmarks of triaxiality-chirality and wobbling-in the same nucleus.

17 pages, 13 figures