Exactly solvable pairing Hamiltonian for heavy nuclei

We present a new exactly solvable Hamiltonian with a separable pairing interaction and nondegenerate single-particle energies. It is derived from the hyperbolic family of Richardson-Gaudin models and possesses two free parameters, one related to an interaction cutoff and the other to the pairing strength. These two parameters can be adjusted to give an excellent reproduction of Gogny self-consistent mean-field calculations in the Hartree-Fock basis. © 2011 American Physical Society.We acknowledge support from a Marie Curie Actions grant of the European Community (Project No. 220335), the Spanish Ministry for Science and Innovation (Projects No. FIS2009- 07277 and No. FPA2009-08958), and the Mexican Secretariat of Public Education (Project No. PROMEP 103.5/09/4482).Peer Reviewe