1 research outputs found
A Higher-Order Calculation of Scattering in Cut-Off Effective Field Theory
We report a next-to-leading-order (NLO) chiral perturbation theory
calculation of the neutron-proton scattering cross section in the
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 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.Comment: Substantial changes made in texts and Fig.2. To appear in Phys. Lett.