High-momentum and High-excitation Properties of the Deuteron with Realistic Nucleon-nucleon Interactions

In nuclear ab initio calculations, nucleon-nucleon interactions are softened via renormalization in order to improve the convergence of calculations. The high-momentum and high-excitation properties of nuclei are not well investigated quantitatively with softened interactions to identify where they may lose predictive power though the low energy observables remain nearly unchanged after the renormalization. In this work, we study nuclear high-momentum properties and high-excitation properties with realistic interactions taking the simplest nucleus, i.e., deuteron, as an example. In particular, we study the nucleon momentum distribution and photoabsorption cross section with a chiral effective field theory interaction at N³LO and two softened interactions based on it, i.e., N³LO-SRG and Daejeon16 interactions. We find that the nucleon momentum distributions of the deuteron calculated with these two soft interactions are significantly suppressed at momenta above 200 MeV in comparison to those calculated with the N³LO chiral interaction. The photoabsorption cross sections of the deuteron calculated with these three interactions are overall in agreement with the experimental data. The N³LO-SRG results deviate slightly from the experimental data above about 15 MeV due to the renormalization process. The Daejeon16 results deviate more apparently from the experimental data above the peak value compared to the N³LO-SRG results due to the phase equivalent transformations.