fourth order (also known as next-to-next-to-next-to-leading order) on peripheral partial
waves of nucleon-nucleon scattering. Our calculations are based upon the analytical studies
by Kaiser. It turns out that the contribution of fourth order is substantially smaller than the one
of third order, indicating convergence of the chiral expansion. We compare the prediction
from chiral pion exchange with the corresponding one from conventional meson theory as …