Effects of triaxiality and residual np interaction in the proton emission from Ho140

Abstract

We present a detailed theoretical investigation of proton emission from $^{140}\mathrm{Ho}$ within the nonadiabatic quasiparticle approach. The calculated proton emission half-life reproduces well the measured data. The importance of triaxiality and of the residual $np$ interaction are studied. The ground state spin and parity of $^{139}\mathrm{Dy}$ (daughter) and $^{140}\mathrm{Ho}$ (parent) are ascertained unambiguously as $7/{2}^{+}$ and ${3}^{\ensuremath{-}}$, respectively, by analyzing the rotational energies, half-lives, and branching ratios.