Leading order relativistic chiral nucleon-nucleon interaction**Supported by National Natural Science Foundation of China (11375024, 11522539, 11335002, 11375120), DFG and NSFC through funds provided to the Sino-German CRC 110 “Symmetries and the Emergence of Structure in QCD” (NSFC Grant No. 11621131001, DFG Grant No. TRR110), the Major State 973 Program of China (2013CB834400), the China Postdoctoral Science Foundation (2016M600845, 2017T100008), the

Abstract

Motivated by the successes of relativistic theories in studies of atomic/molecular and nuclear systems and the need for a relativistic chiral force in relativistic nuclear structure studies, we explore a new relativistic scheme to construct the nucleon-nucleon interaction in the framework of covariant chiral effective field theory. The chiral interaction is formulated up to leading order with covariant power counting and a Lorentz invariant chiral Lagrangian. We find that the relativistic scheme induces all six spin operators needed to describe the nuclear force. A detailed investigation of the partial wave potentials shows a better description of the and phase shifts than the leading order Weinberg approach, and similar to that of the next-to-leading order Weinberg approach. For the other partial waves with angular momenta , the relativistic results are almost the same as their leading order non-relativistic counterparts.