Ratational energies for the asymmetric rotor model for odd-mass nuclei

Abstract

We study the effect of ellipsoidal nuclear deformation in odd-mass-nuclear rotational band structure, the magnetic moment, and electric quadrupole reduced transition probabilities. Also, we study the relationship between the rotational bands of an ellipsoidally deformed nucleus and the vibrational and rotational bands of a spheridally deformed nucleus with γ-vibration-rotation interaction in the limit of γ approaching 0 or 1 3 π . Equations for the asymmetric rotor motion are derived. By using T.D. Newton's single-particle eigenvalues and eigenvectors, we then present numerical calculations showing rotational spectra associated with an odd nucleon in an ellipsoidal well. The calculations for the N = 4 and N = 2 shells were done on an IBM 709 computer. Numerical results are discussed in terms of the β and γ deformation parameters required to give the known spins of the odd-mass cesium isotopes Cs 127 to Cs 137. The rotational energy spectrum, magnetic moment of ground state, and various E2 transition probabilities are calculated for Cs 131 for several deformations, with best energy spectrum fit at β = 0.28, γ = 38 deg. There are difficulties with the transition probabilities and magnetic moment.