Thermal mass shift of nucleons

Abstract The mass shift Δm N of a nucleon in the finite temperature pion gas is calculated in the case of an arbitrary nucleon momentum. A general formula is used which relates the in-medium mass shift Δm ( E ) of a particle to the real part of the forward scattering amplitude Re F ( E ) of this particle on the constituents of the medium and its applicability domain is formulated. The mass shift of the nucleon in thermal equilibrium with the pion gas is also calculated.