Evidence of chiral bands in even-even nuclei

Abstract

Evidence for chiral doublet bands has been observed for the first time in the even-even nucleus $^{136}\mathrm{Nd}$. One chiral band was firmly established. Four other candidates for chiral bands were also identified, which can contribute to the realization of the multiple pairs of chiral doublet bands ($\mathrm{M}\ensuremath{\chi}\mathrm{D}$) phenomenon. The observed bands are investigated by the constrained and tilted axis cranking covariant density functional theory (TAC-CDFT). Possible configurations have been explored. The experimental energy spectra, angular momenta, and $B(M1)/B(E2)$ values for the assigned configurations are globally reproduced by TAC-CDFT. Calculated results support the chiral interpretation of the observed bands, which correspond to shapes with maximum triaxiality induced by different multiquasiparticle configurations in $^{136}\mathrm{Nd}$.