A Novel Regularization Scheme for Nucleon-Nucleon Lattice Simulations with Effective Field Theory

We propose a new regularization scheme to study the bound state of two-nucleon systems in lattice effective field theory. Inspired by a continuum effective field theory calculation, we study an exponential regulator acting on the leading-order and next-to-leading order interactions, consisting of local contact terms. By fitting the low-energy coefficients to deuteron binding energy and the asymptotic normalization coefficient on a lattice simulation, we extract the effective range expansion (ERE) parameters in the S-3(1) channel to order p(2). We explore the impact of different powers of the regulator on the extracted ERE parameters for the lattice spacing a = 1.97 fm. Moreover, we investigate how the implementation of the regularization scheme improves the predicted ERE parameters on the lattice spacing in the range of 1.4 <= a <= 2.6 fm. Our numerical analysis indicates that for lattice spacing greater than 2 fm, the predicted observables are very close to the experimental data.