Local chiral potentials with Δ -intermediate states and the structure of light nuclei

We present fully local versions of the minimally nonlocal nucleon-nucleon potentials constructed in a previous paper [Piarulli, Phys. Rev. C 91, 024003 (2015)]PRVCAN0556-281310.1103/PhysRevC.91.024003, and use them in hypersperical harmonics and quantum Monte Carlo calculations of ground and excited states of H3, He3, He4, He6, and Li6 nuclei. The long-range part of these local potentials includes one- and two-pion exchange contributions without and with Δ isobars in the intermediate states up to order Q3 (Q denotes generically the low momentum scale) in the chiral expansion, while the short-range part consists of contact interactions up to order Q4. The low-energy constants multiplying these contact interactions are fitted to the 2013 Granada database in two different ranges of laboratory energies, either 0-125 MeV or 0-200 MeV, and to the deuteron binding energy and nn singlet scattering length. Fits to these data are performed for three models characterized by long- and short-range cutoffs, RL and RS, respectively, ranging from (RL,RS)=(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.