Minimally non-local nucleon-nucleon potentials with chiral two-pion exchange including $\hat{I}”$'s

Abstract

We construct a coordinate-space chiral potential, including $\hat{I}”$-isobar intermediate states in its two-pion-exchange component. The contact interactions entering at next-to-leading and next-to-next-to-next-to-leading orders ($Q^2$ and $Q^4$, respectively, $Q$ denoting generically the low momentum scale) are rearranged by Fierz transformations to yield terms at most quadratic in the relative momentum operator of the two nucleons. The low-energy constants multiplying these contact interactions are fitted to the 2013 Granada database, consisting of 2309 $pp$ and 2982 $np$ data (including, respectively, 148 and 218 normalizations) in the laboratory-energy range 0--300 MeV. For the total 5291 $pp$ and $np$ data in this range, we obtain a $\ddot{I}{‡}^2$/datum of roughly 1.3 for a set of three models characterized by long- and short-range cutoffs, $R_{\mathrm{L}}$ and $R_{\mathrm{S}}$ respectively, ranging from $(R_{\mathrm{L}},R_{\mathrm{S}})=(1.2,0.8)$ fm down to $(0.8,0.6)$ fm. The long-range (short-range) cutoff regularizes the one- and two-pion exchange (contact) part of the potential.

32 pages, 19 figures, accepted for publication as a Regular Article in Physical Review C