The intrinsic-excitation-coupled-to-rotator model (IECRM) for odd-mass nuclei

In the present work a new approach to the low-lying (rotational) spectra of the odd-mass deformed nuclei is presented. Starting from the many-body Schroedinger equation one reaches the equations of a model, called "intrinsic-excitation-coupled-to-rotator model" (IECRM). To do this we use the knowledge concerning ground-state rotational bands and energies in neighbouring even-even nuclei and apply a projection technique. It is shown that IECRM is a generalization of the well-known "rotator model" and gives, at the same time, a more adequate procedure when one works (as usually) in a limited basis of single-(quasi)-particle states. As a consequence it follows that the core parameters of an odd-mass nucleus are considerably changed in comparison with the corresponding quantities of the even-even neighbouring nuclei.