DISSIPATIVE HELD THEORY WITH THE CALDEIRA-LEGGETT METHOD AND ITS APPLICATION TO DISORIENTED CHIRAL CONDENSATION

The effective field theory including the dissipative effect is develop ed based on the Caldeira-Leggett theory at the classical level. After the integration of the small field fluctuations considered as the fiel d radiation, the integrodifferential field equation is given and shown to include dissipative effects. In that derivation, special care shou ld be taken for the boundary condition of the integration. Application to the linear a model is given, and the decay process of the chiral c ondensate is calculated with it, both analytically in the linear appro ximation and numerically. With these results, we discuss the stability of chiral condensates within the quenched approximation.