Study Effect of Majorana Coefficient on the Energy Levels of 138-144,148Gd Even-Even Isotopes Using IBM-2

The mixed symmetry states property (MSS) for even-even 138-144 and 148 Gd isotopes was studied using IBM-2. This model discovered and emphasised various empirically questionable states and provided good agreement for the excited energy levels for the energy bands ground, g-band and acceptable for the excitations – β and γ bands. The effect of the Majorana parameter was studied as a function of changing the mixing symmetry of the levels using three different values (0.005, 0.02, and 0.04), and the value of the Majorana parameter was almost constant. By increasing the Majorana parameter to the values (0.02 and 0.04), the mixing levels began to appear clearly, especially the levels. Energy levels and energy ratios showed that 138Gd and 140Gd are between rotational SU(3) and gamma-unstable O(6) symmetries, and 142Gd, 144Gd, and 148Gd are transitional nuclei among gamma-unstable O(6) to vibrational SU(5) symmetries. The results of theoretical and practical energy levels were in good agreement.

IBM-2, Energy levels, MSS, Gd isotope, SU(3), SU(5), O(6).

10.52113/2/12.01.2025/94-103