A new approach to approximate symmetry restoration with density dependent forces: The superdeformed band in 192Hg

A consistent derivation of approximate particle number symmetry restoration with density dependent forces is provided. An additional term absent in usual derivations is found. The theory is applied to the calculation of the superdeformed ground state band of 192Hg with the finite range density dependent Gogny force. The agreement with the experimental results is very satisfactory. The comparison with earlier approximations is also discussed.