Evolution of nuclear shell structure due to the pion exchange potentialWenHui Long1, 2, Hiroyuki Sagawa2, Jie Meng1, 3 and Nguyen Van Giai4, 5
1 School of Physics, Peking University - 100871 Beijing, China
2 Center for Mathematical Sciences, University of Aizu - Aizu-Wakamatsu, 965-8580 Fukushima, Japan
3 Department of Physics, University of Stellenbosch - Stellenbosch, South Africa
4 CNRS-IN2P3, UMR 8608 - F-91406 Orsay Cedex, France, EU
5 Université Paris-Sud - F-91405 Orsay, France, EU
received 1 October 2007; accepted in final form 12 February 2008; published April 2008
published online 13 March 2008
The evolution of nuclear shell structure is investigated for the first time within density-dependent relativistic Hartree-Fock theory and the role of -exchange potential is studied in detail. The energy differences between the neutron orbits in the N=82 isotones and between the proton ones in the Z=50 isotopes are extracted as a function of neutron excess N - Z. A kink around Z=58 for the N=82 isotones is found as an effect of pion correlations. It is shown that the inclusion of -coupling plays a central role to provide substantial isospin dependence of the energy differences. In particular, the tensor part of the -coupling has an important effect on the characteristic isospin dependence observed in recent experiments.
21.30.Fe - Forces in hadronic systems and effective interactions.
21.60.Jz - Nuclear Density Functional Theory and extensions (includes Hartree-Fock and random-phase approximations).
24.10.Cn - Many-body theory.
© EPLA 2008