105Tc nuclear structure and systematic evolution of states of 1/2+[431] intruder band in odd-A 95, 97,99,101,103,105,107Tc isotopes

Previously observed negative and positive parity states of ¹⁰⁵Tc were studied in the framework of particle-rotor model. Transition properties and experimental energies were compared to the predictions of the model calculations. A systematic study of the evolution of the intruder π1/2+[413] band in the nuclear structure of odd-A Technetium isotopes ^{95,97,99,101,103,105,107}Tc is presented as well. The existence of this intruder band has been argued previously in ^{95,97,99,101,103}Tc isotopes (partially populated) and fully observed and confirmed in ¹⁰⁵Tc. It will be shown that changes in deformation and subsequently the position of Fermi level vis a vis the 1/2+[431] intruder orbital originating from the π (d_5/2, g_7/2) subshells predominantly affect these systematic changes. All four interpreted experimental rotational bands are naturally predicted by the rotational model as bands build on states of good Ω originating from 5/2+[422], 5/2-[303], 3/2-[301] and 1/2+[431] orbitals near the Fermi level in deformed ¹⁰⁵Tc (strong coupling). Further experimental investigation about missing data is needed for those observed low lying states in both ¹⁰⁵Tc and ¹⁰³Tc in order to confirm the presence of the 1/2-[301] rotational band that is well defined in lighter ^95,97,99,101Tc isotopes.

SIGNATURE SPLITTING IN 173W WITH TRIAXIAL PARTICLE ROTOR MODEL

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 ν7/2+[633] and nonintruder orbital ν5/2-[512] in 173 W . Excellent agreement with the observed energy spectra has been achieved for both bands. Signature splitting for band ν7/2+[633], and band ν5/2-[512] before the onset of signature inversion, is satisfactorily reproduced by introducing the γ degree of freedom. The phase and amplitude of signature splitting in band ν5/2-[512] are attributed to strong competition between 2f7/2 and 1h9/2 components. However, the self-consistent explanation of signature inversion in band ν5/2-[512] is beyond the present one quasi-neutron coupled with a triaxially deformed rotor.