High-spin states and possible chirality in odd-odd Ag110

Abstract

High-spin states of $^{110}\mathrm{Ag}$ have been studied by in-beam $\ensuremath{\gamma}$-ray spectroscopic techniques using the fusion-evaporation reaction $^{110}\mathrm{Pd}$($^{7}\mathrm{Li}, \ensuremath{\alpha}3\mathrm{n}$)$^{110}\mathrm{Ag}$ at a beam energy of 46 MeV. The previously known level scheme of $^{110}\mathrm{Ag}$ is significantly extended and modified with the addition of 50 new $\ensuremath{\gamma}$ transitions and 21 new levels. In total, four new rotational bands are observed, among which two negative-parity coupled bands are assigned to the four-quasiparticle $\ensuremath{\pi}{g}_{9/2}^{\ensuremath{-}1}\ensuremath{\bigotimes}\ensuremath{\nu}{h}_{11/2}{({g}_{7/2}/{d}_{5/2})}^{2}$ configuration based on the quasiparticle alignment analysis and cranked shell model calculations. The properties of both bands show general agreement with the fingerprints of chiral rotation, and thus such two negative-parity bands are suggested to be candidates for near degenerate chiral doublet bands. A new decoupled $\mathrm{\ensuremath{\Delta}}I=2$ band decaying directly to the yrast band is established, and probably results from one-particle-one-hole (1p-1h) proton excitation from the ${g}_{9/2}$ orbital to the ${g}_{7/2}$ orbital across the large $Z=50$ shell gap, i.e., the 2p2h $\ensuremath{\pi}{g}_{9/2}^{\ensuremath{-}2}{g}_{7/2}\ensuremath{\bigotimes}\ensuremath{\nu}{h}_{11/2}$ configuration. In addition to, a weak positive-parity sequence consisting of magnetic dipole $(M1)$ and no $E2$ crossover transitions is also identified in the present work.