Renormalizations in nonlinear chiral theory

A program of renormalizations is realized for nonlinear chiral theory using the superpropagator method of calculation. A number of relations for the renormalization constants (Ward identities) is found from the requirement of chiral invariance. Calculations are made of the strong $\pi N$ coupling constant and the axial constant of $\beta$ decay in the single-loop approximation, as well as the two-loop corrections to the pion self-energy. The calculations show that despite the strong $\pi N$ coupling the contributions from the higher orders are relatively small ($\sim 20-30\%$).