Perturbative renormalization of chiral nuclear forces at subleading order in the channel
Phys. Rev. C 112, 064004 – Published 15 December, 2025
DOI: https://doi.org/10.1103/7jjf-gy3m
Abstract
We investigate renormalization of chiral nuclear forces in the coupled channel of of nucleon-nucleon scattering. The one-pion exchange potential is treated nonperturbatively at leading order while subleading potentials are perturbations. Very much like the uncoupled channel of , the singular attraction of one-pion exchange gives rise to the so-called genuine exceptional cutoffs, where artificial correlations between subleading contact operators emerge and they result in ill-defined values of the low-energy constants. To address this issue we follow the solution proposed for in [Peng et al., Phys. Rev. C 110, 054001 (2024)] and apply it to . The truncation uncertainty of an effective field theory allows certain degrees of freedom in choosing renormalization conditions, or fitting schemes of the low-energy constants. By exploiting this freedom near the exceptional cutoffs, we are able to remove the said correlations. A much-mitigated cutoff variation of the phase shifts, which is acceptable to the power counting, is thus obtained.