On Origin and Physical Meaning of Ward-Like Identity in Dual-Resonance Model

Abstract

It is shown for the string model that the Ward-like identities in the dual-resonance model proposed by Fubini, Veneziano and Virasoro follow directly from the requirement that the theory must be covariant under an arbitrary transformation of the Lagrange coordinate labeling each constituent part of the string. Thus at least for the string model, these identities are a necessary consequence of a general principle to be satisfied by any consistent physical theory. Our discussion is restricted to the case α(0)=1, i.e., intercept one.