The Standard Model at Low Energies*

The hadronic sector of the standard model at low energies is described by a non–decoupling effective field theory, chiral perturbation theory. An introduction is given to the construction of effective chiral Lagrangians, both in the purely mesonic sector and with inclusion of baryons. The connection between the relativistic formulation and the heavy baryon approach to chiral perturbation theory with baryons is reviewed. Lectures given at the 6 Indian–Summer School on Intermediate Energy Physics Interaction in Hadronic Systems Prague, August 25 31, 1993 To appear in the Proceedings (Czech. J. Phys.) * Work supported in part by FWF, Project No. P09505-PHY (EURODAΦNE Collaboration)