Chiral Wobbling in 135Pr

Chirality and wobbling are the two unique signatures that help in the identification of the rare triaxial shape in nuclei. While both these modes have been separately established in a few limited regions of the nuclear chart, the coexistence of chirality and wobbling in a nucleus, a Chiral Wobbler, has never been observed so far. Using a high statistics Gammasphere experiment with the ¹²³Sb(¹⁶O,4n)¹³⁵Pr reaction, the very first observation of a Chiral Wobbler in ¹³⁵Pr has been made. In addition to the previously established n_ω = 1 and n_ω = 2 wobbling bands, two chiral-partner bands with the configuration πh_{11 / 2} × νh_11/2^-2 have been observed in this nucleus. Angular distribution analyses of the ΔI = 1 connecting transitions between the two chiral partners have revealed their characteristic M1/E2 nature. Tilted axis cranking (TAC) calculations are found to be in good agreement with the experiment.

This work has been supported by the U.S. NSF Grant No. PHY-1713857.