Nuclear Gamma-soft Character in ¹²⁸Ba

We report the properties of gamma soft O(6) of 128Ba isotones with neutron N = 72 using Interacting Vector Boson Model (IVBM), interacting Boson Model (IBM-1), Bohr-Mottelson Model (BM), and Doma-El-Gendy (D-G) relation. The first energy level ( ) and ratio have been investigated which show that 128Ba has gamma-soft character. The curves Eγ/Vs.J of E-GOS of even 128Ba nucleus were compared with the standard curves of vibrational, gamma soft and rotational limits. The staggering factors were studied of available measured data of 128Ba nucleus. The yrast levels of this isotope are calculated by the model of VBMI, IBM-1, BM and D-G and they were compared by measured data. The negative parity band of 128Ba was calculated by IVBM and BM model and compared with experimental values.

High Spin Structure of 122Xe

High spin states in the isotope 122Xe were populated using the reaction 96Zn(30Si,2n)122Xe at a beam energy of 135 MeV. The subsequent γ-ray deexcitation was studied using γ-ray spectroscopic methods. The analysis of γ-γ coincidences has revealed two new structures of competing dipole and quadrupole transitions. The highest states of a positive parity band provide characteristics consistent with an approach to band termination.

"Beat" Patterns of Odd-Even Staggering in Octupole Bands of Light Actinides

The Δ I = 1 staggering (odd-even staggering) in octupole bands of light actinides. is found to exhibit a "beat" behaviour as a function of the angular momentum J, forcing us to revise the traditional belief that this staggering decreases gradually to, zero and then remains at this zero value. Various algebraic models (spf-Interacting Boson Model, spdf-IBM, Vector Boson Model, Nuclear Vibron Model) predict in their su(3) limits constant staggering for this case, being thus unable to describe the "beat" behaviour. An explanation of the "beat" behaviour is given in terms of two Dunham expansions (expansions in terms of powers of I ( I + 1) ) with slightly different sets of coefficients for the ground state band and the negative parity band, the difference in the values of the coefficients being attributed to Coriolis couplings to other negative parity bands.

THEORETICAL INVESTIGATION OF POSITIVE PARITY BAND STRUCTURE OF Y AND Nb ISOTOPES

The positive parity band structure of odd mass neutron-rich 97 – 103 Y and 99 – 105 Nb 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 97 Y to 99 Y and 99 Nb to 101 Nb . The PSM calculations also demonstrate the multi-quasiparticle structure in these nuclei.

CONFIGURATION ASSIGNMENT OF THE POSITIVE-PARITY STRUCTURES IN 108Ag

The high-spin states of 108 Ag have been studied by the in-beam γ spectroscopy with the reaction 104 Ru (7 Li ,3n)108 Ag at a beam energy of 33 MeV. The previously known positive-parity band structures have been extended up to higher spins. Their configurations are discussed based on alignments, band-crossing frequencies, and B(M1)/B(E2) ratios.