Multireference covariant density-functional theory for the low-lying states of odd-mass nuclei

We extend multireference covariant density -functional theory (MR-CDFT) based on a relativistic pointcoupling energy functional to describe the low-lying states of odd -mass nuclei. The nuclear wave function is constructed as a superposition of quadrupole-octupole deformed mean -field configurations, with projection onto angular momentum, particle numbers, and parity within the framework of the generator coordinate method. Using 25Mg as an example, we calculate the energy spectrum, electric multipole, and magnetic dipole transition strengths based on three different schemes for the mean -field configurations of odd -mass nuclei. We find that the low -energy structure of 25Mg is reasonably reproduced in all three schemes. In particular, the effect of octupole correlation is illustrated in the application to the low-lying parity doublets of 21Ne. This work demonstrates the success of the MR-CDFT for the low-lying states of odd -mass nuclei with possible strong quadruple-octupole correlations.