Narrow Results

The positive parity band structure of odd mass neutron-rich ^97–103Y and ^99–105Nb nuclei has been studied using microscopic technique known as the projected shell model (PSM) with the deformed single-particle states generated by the standard Nilsson potential. The nuclear structure properties like yrast spectra, energy splitting, moment of inertia, rotational frequencies and reduced transition probabilities B(M1) and B(E2) have been calculated and their comparison with the available experimental data has been made. A shape evolution has also been predicted in these isotopes as one moves from ⁹⁷Y to ⁹⁹Y and ⁹⁹Nb to ¹⁰¹Nb. The PSM calculations also demonstrate the multi-quasiparticle structure in these nuclei.

The properties of the yrast states for ^100-110Pd even–even (e–e) nuclei have been established. The relation between the moment of inertia 2ϑ/ℏ² and the square of the rotational energy (ℏω)² has been drawn to identify the back-bending that may occur at a certain state for each isotope. The relation between gamma-energy over spin Eγ/I as a function of spin I has been drawn to determine the evolution in each isotope ranging from vibration to rotational properties. The suitable limit in the interacting boson model IBM-1 has been used to calculate the yrast states for each isotope, which are then compared with the experimental results.

Negative parity energy states in ^121–131La have been studied using Projected Shell Model (PSM). Some nuclear structure properties like yrast spectra, back-bending in moment of inertia, reduced transition probabilities and band diagrams have been described. The experimental feature of the co-existence of prolate–oblate shapes in ^125–131La isotopes has been satisfactorily explained by PSM results. Comparison of the theoretical data with their experimental counterparts has also been made. From the calculations, it is found that the yrast states arise because of multi-quasiparticle states.

A theoretical study of the structure of some odd mass Rh nuclei in the A ~ 100 mass region is carried out by using the angular momentum projection technique implemented in the projected shell model (PSM). The influence of the high-j orbitals (h_11/2 for neutrons and g_9/2 for protons) on the structure of ^107–113Rh isotopes is investigated in the present case by assuming an axial symmetry in the deformed basis. For these isotopes, the structure of multi-quasi-particle qp bands is studied along the yrast line in detail. Further, the phenomenon of back-bending is also studied theoretically and is found to be in agreement with the experimental data. The reduced transition probabilities, i.e., B(E2) and B(M1) for the yrast band are also obtained from the PSM wave functions for the first time, thereby providing an opportunity for the experimentalists to work for this data.

The projected shell model (PSM) with the deformed single-particle states, generated by the standard Nilsson potential, is applied to study the negative-parity high spin states of ${}^{115\text{–}125}\text{Sb}$ nuclei. The nuclear structure quantities like band structure and back-bending in moment of inertia have been calculated with PSM method and are compared with the available experimental data. In addition, the reduced transition probabilities, i.e., B$(E2)$ and B$(M1)$, are also obtained for the yrast band of these isotopes for the first time by using PSM wave function. A multi-quasiparticle structure has been predicted for ${}^{115\text{–}125}\text{Sb}$ isotopes by the present PSM calculations.