PHYSICAL JOURNAL A Nuclear pairing from chiral pion-nucleon dynamics

Abstract. We use a recently improved version of the chiral nucleon-nucleon potential at next-to-next-to-leading order to calculate the 1S0 pairing gap in isospin-symmetric nuclear matter. The pairing potential consists of the long-range one- and two-pion exchange terms and two short-distance NN-contact couplings. We ¯nd that the inclusion of the two-pion exchange at next-to-next-to-leading order reduces substantially the cuto ® dependence of the 1S0 pairing gap determined by solving a regularised BCS equation. Our results are close to those obtained with the universal low-momentum nucleon-nucleon potential Vlow-k or the phenomenological Gogny D1S force. PACS. 13.75.Gx Pion-baryon interactions { 21.30.Cb Nuclear forces in vacuum { 21.30.Fe Forces in hadronic systems and e®ective interactions { 21.60.-n Nuclear structure models and methods The self-consistent mean-¯eld framework, extended to take into account the most important correlations, pro-vides at present the only viable microscopic description of structure phenomena in light and heavy nuclei over the entire periodic table. A broad range of successful applica-tions to nuclear structure and low-energy dynamics char