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The three parameters nuclear softness model (NS3) have been applied to eleven superdeformed (SD) bands of A ≈190 mass region namely: 191 Hg(SD2,SD3), 192 Hg(SD1), 194 Hg(SD1,SD2), 193 Tl(SD1,SD2), 194 Tl(SD1,SD3, SD5) and 194 Pb(SD1). The level spins and the model parameters are determined by fitting the electric quadrupole transition energies E γ with the experimental ones, by using a computer simulated search program. Rotational frequencies ħω, kinematic J (1) and dynamic J (2) moments of inertia and the quadrupole deformation parameter β 2 have been calculated. In all cases of our selected SD bands the results obtained are in good agreement with experimental ones. J (2) reveal a steady increase with ħω, this can be attributed to the successive alignment of πi 13/2 (N = 6) and υj 15/2 (N = 7) intruder orbitals in the presence of dynamical pairing correlations. The presence of ΔI = 2 staggering in the two SD bands 1,2 of 194 Hg and in the three SD bands 1,3,5 of 194 Tl have been investigated by calculating the staggering parameter which represent the fourth order derivative of the gamma-ray transition energies. Also the ΔI = 1 staggering in SD bands of odd nuclei has been investigated in the signature partner pairs 191 Hg (SD2, SD3) and 193 Tl (SD1, SD2). The yrast SD bands in the isotones 194 Pb and 192 Hg have almost identical transition energies which implies that their J (2) are also identical. This indicates that either the two occupied 5/2+[642] protons have a very weak influence on E γ and J (2) . |
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