M. Piarulli

TL;DR: In this article, a coordinate-space chiral potential with Δ-isobar intermediate states in its two-pion-exchange component up to order Q3 was constructed, where the contact interactions entering at next to leading and next to next-to-next-thresholding orders (Q2 and Q4, respectively) were rearranged by Fierz transformations to yield terms at most quadratic in the relative momentum operator of the two nucleons.

Abstract: We present fully local versions of the minimally nonlocal nucleon-nucleon potentials constructed in a previous paper [Piarulli et al., Phys. Rev. C 91, 024003 (2015)], and use them in hypersperical harmonics and quantum Monte Carlo calculations of ground and excited states of $^{3}\mathrm{H}$, $^{3}\mathrm{He}$, $^{4}\mathrm{He}$, $^{6}\mathrm{He}$, and $^{6}\mathrm{Li}$ nuclei. The long-range part of these local potentials includes one- and two-pion exchange contributions without and with $\mathrm{\ensuremath{\Delta}}$ isobars in the intermediate states up to order ${Q}^{3}$ ($Q$ denotes generically the low momentum scale) in the chiral expansion, while the short-range part consists of contact interactions up to order ${Q}^{4}$. 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, ${R}_{\mathrm{L}}$ 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.

TL;DR: Green's function Monte Carlo calculations of light nuclei based on the family of local two-body interactions presented by the group in a previous paper are presented, accurate to ≤2% of the binding energy, in very satisfactory agreement with experimental data.

TL;DR: In this paper, the authors investigated the validity of the chiral effective field theory (EFT) approach to describe the strong-interaction dynamics in these few-nucleon systems and their response to electromagnetic probes.

TL;DR: In this article, it was shown that a short-range lepton-number-violating operator is only needed in spin-singlet $S$-wave transitions, while leading-order transitions involving higher partial waves depend solely on long-range currents.