High-spin level structure ofRh115: Evolution of triaxiality in odd-even Rh isotopes

Abstract

High-spin excited states in the neutron-rich nucleus 115 Rh have been identified for the first time by studying prompt γ rays from the spontaneous fission of 252 Cf with the Gammasphere detector array. A new yrast band and a side-band are built in 115 Rh. This level scheme is proposed to be built on the 7/2 + ground state. The existence of a large signature splitting and an yrare band in 115 Rh shows typical features of a triaxially deformed nucleus. The Rigid Triaxial Rotor plus Particle model is used to interpret the level structure of 115 Rh. The level energies, gamma branching ratios, the large signature splitting in the yrast band, and the inverted signature splitting in the yrare band in 115 Rh are reproduced very well. Strong K-mixing occurs in 115 Rh at high spin.

Excited levels in the multishaped Pd117 nucleus studied via β decay of Rh117

“…Consequently the β feeding values observed in this work, which are shown in Table II The knowledge of the spin parity of the ground state of 117 Rh is of prime importance for assigning spins and parities to levels in 117 Pd, populated in the β decay of 117 Rh. An axially asymmetric deformation is proposed for rhodium isotopes to explain the nuclear structure observed in spectroscopy measurements [1,38,39]. Theoretical calculations of the potential-energy surface for 117 Rh, based on the FRLDM macroscopic-microscopic model, show a single minimum for the axial-asymmetry coordinate γ ≈ 45…”