2015/08/08 by S. A. Changizi, Chong Qi, R. Wyss · 1 citation
Physics and Astronomy · #nucl-th
paper · pdf · doi:10.1016/j.nuclphysa.2015.04.010
published as Nuclear Physics A 940, 210 (2015) · 10 pages, 9 figures
arxiv created 2015/08/08 · arxiv updated 2015/08/11
The empirical pairing gaps derived from four different odd-even mass staggering formulas are compared. By performing single-j shell and multi-shell seniority model calculations as well as by using the standard HFB approach with Skyrme force we show that the simplest three-point formula ΔC^ (3)(N)=(1)/(2)[B(N,Z)+B(N-2,Z)-2B(N-1,Z)] can provide a good measure of the neutron pairing gap in even-N nuclei. It removes to a large extent the contribution from the nuclear mean field as well as contributions from shell structure details. It is also less contaminated by the Wigner effect for nuclei around N=Z. We also show that the strength of Δ^ (3)C(N) can serve as a good indication of the two-particle spatial correlation in the nucleus of concern and that the weakening of Δ^ (3)C(N) in some neutron-rich nuclei indicates that the di-neutron correlation itself is weak in these nuclei.