A higher-order calculation of np scattering in cut-off effective field theory

Chang Ho Hyun, Tae-Sun Park, Dong-Pil Min
2000 Physics Letters B  
We report a next-to-leading-order (NLO) chiral perturbation theory calculation of the neutron-proton scattering cross section in the ${}^1S_0$ channel using a cut-off regularization. The inclusion of two-pion exchanges in the irreducible diagrams -- or potential -- figuring at NLO is found to be important in enlarging the domain of validity of the effective field theory. We are able to reproduce the {\it empirical} scattering phase shift up to p=300 MeV -- which is comparable to the cutoff
more » ... to the cutoff scale involved -- with an agreement which is superior to results of other effective field theory approaches. We also discuss the role of the cutoff as a renormalization prescription and the importance of the explicit pion degree of freedom in scattering process.
doi:10.1016/s0370-2693(99)01487-2 fatcat:qm3qpiu3yfetxosgeku5pw6apa