Abstract
We present solutions of the BCS gap equation in the channels and in neutron matter based on nuclear interactions derived within chiral effective field theory (EFT). Our studies are based on a representative set of nonlocal nucleon-nucleon (NN) plus three-nucleon (3N) interactions up to next-to-next-to-next-to-leading order () as well as local and semilocal chiral NN interactions up to and , respectively. In particular, we investigate for the first time the impact of subleading 3N forces at on pairing gaps and also derive uncertainty estimates by taking into account results for pairing gaps at different orders in the chiral expansion. Finally, we discuss different methods for obtaining self-consistent solutions of the gap equation. Besides the widely used quasilinear method by Khodel et al., we demonstrate that the modified Broyden method is well applicable and exhibits a robust convergence behavior. In contrast to Khodel's method it is based on a direct iteration of the gap equation without imposing an auxiliary potential and is straightforward to implement.
- Received 18 October 2016
DOI:https://doi.org/10.1103/PhysRevC.95.024302
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