  We treat the propagation of nucleon in nuclear matter by evaluating the
ensemble average of the two-point function of nucleon currents in the framework
of the chiral effective field theory. We first derive the effective parameters
of nucleon to one loop. The resulting formula for the effective mass was known
previously and gives an absurd value at normal nuclear density. We then modify
it following Weinberg's method for the two-nucleon system in the effective
theory. Our results for the effective mass and the width of nucleon are
compared with those in the literature.

High Energy Physics - Phenomenology