Beyond the relativistic mean-field approximation: Configuration mixing of angular-momentum-projected wave functions

We report the first study of restoration of rotational symmetry and fluctuations of the quadrupole deformation in the framework of relativistic mean-field models. A model is developed that uses the generator coordinate method to perform configuration mixing calculations of angular-momentum-projected wave functions, calculated in a relativistic point-coupling model. The geometry is restricted to axially symmetric shapes, and the intrinsic wave functions are generated from the solutions of the constrained relativistic mean-field + BCS equations in an axially deformed oscillator basis. A number of illustrative calculations are performed for the nuclei $^{194}\mathrm{Hg}$ and $^{32}\mathrm{Mg}$, in comparison with results obtained in nonrelativistic models based on Skyrme and Gogny effective interactions.