Coulombic effect and renormalization in nuclear pairing

Abstract

We investigate effects of the Coulomb force on the nuclear pairing properties by performing the Gogny Hartree-Fock-Bogolyubov calculations for the $N=20$, $28$, $50$, $82$ and $126$ nuclei. The Coulomb force reduces the proton pair energy and the even-odd mass difference by about 25%, except for nuclei at and around the proton shell or subshell closure. We then propose a renormalization scheme via a reduction factor ${\gamma }_p$ for the proton pairing channel. It is found that a single value of ${\gamma }_p(=0.90)$ well takes account of the Coulombic effect, for nuclei covering wide range of the mass number and the neutron excess including the nuclei around the shell or subshell closure.

5 pages, 2 figures; to appear in PRC (Rapid Communication)

References in corpus (9)

• Nuclear magic numbers: new features far from stability
• Collapse of the N=28 shell closure in ${}^{42}$Si
• Microscopic justification of the Equal Filling approximation
• Further explorations of Skyrme-Hartree-Fock-Bogoliubov mass formulas. IX: Constraint of pairing force to ${}^1{S}_0$ neutron-matter gap
• BCS-BEC crossover of neutron pairs in symmetric and asymmetric nuclear matter
• Effective pairing interactions with isospin density dependence
• Application of Gaussian expansion method to nuclear mean-field calculations with deformation
• Diproton correlation in a proton-rich Borromean nucleus 17Ne
• The Negele-Vautherin density matrix expansion applied to the Gogny force