Odd-even staggerings on nuclear binding energy described by the covariant density functional theory
Institute of Modern Physics, Chinese Academy of Science, Lanzhou 730000, China(Dated: January 10, 2014)The odd-even staggerings (OES) on nuclear binding energies are studied systematically within the covariantdensity functional (CDF) theories, speciﬁcally the relativistic Hartree-Fock-Bogoliubov (RHFB) and the rela-tivistic Hartree-Bogoliubov (RHB) theories. Taking the ﬁnite-range Gogny force D1S as an e ective pairinginteraction, both CDF models can provide appropriate descriptions on the OESs of nuclear binding energies forC, O, Ca, Ni, Zr, Sn, Ce, Gd and Pb isotopes as well as for N = 50 and 82 isotones. However, due to the in-consistence between the non-relativistic pairing interaction and the relativistic e ective Lagrangians, there existsome systematical discrepancies from the data, i.e., the underestimated OESs in light C and O isotopes and theoverestimated ones in heavy region, respectively. Such discrepancies can be eliminated partially by introducinga Z- or N-dependent strength factor into the pairing force Gogny D1S. In addition, successful descriptions ofthe occupation numbers of Sn isotopes are achieved with the optimized Gogny pairing force. Furthermore, theanalysis of the systematics of both pairing e ects and nuclear binding energy indicate the requirement of anuniﬁed relativistic mechanism in both p-p and p-h channels to improve the quantitative precision of the theory.