NONPERTURBATIVE DEFORMATION OF CONFORMAL FIELD-THEORY AND SPONTANEOUSLY BROKEN INTER MASS LEVEL SYMMETRIES IN STRING THEORY

Abstract

We study the deformation of conformal field theory without leaving the fixed points. It is found that an infinite number of higher spin background fields are needed to cancel the q-number anomalies when one goes beyond first order weak field calculation. This phenomenon can be interpreted in string theory as spontaneously broken symmetries between particles with different masses.