A particle rotor model with a quasi-neutron coupled with a triaxially deformed rotor is applied to study signature splitting for bands with intruder orbital $\nu7/2^{ +} [633]$ and non-intruder orbital $\nu5/2^{ -}[512]$ in $^{ 173}$W. Excellent agreement with the observed energy spectra has been achieved for both bands. Signature splitting for band $\nu7/2^{ +} [633]$, and band $\nu5/2^{ -}[512]$ before the onset of signature inversion, is satisfactorily reproduced by introducing the $\gamma$ degree of freedom. The phase and amplitude of signature splitting in band $\nu5/2^{ -}[512]$ is attributed to strong competition between $2f_{ 7/2}$ and $1h_{ 9/2}$ components. However, the explanation of signature inversion in band $\nu5/2^{ -}[512]$ self-consistently is beyond the present one quasi-neutron coupled with a triaxially deformed rotor.
Categories: nucl-th