GAUGE-THEORY RENORMALIZATIONS FROM THE OPEN BOSONIC STRING

We present a unified point of view on the different methods available in the literature to extract gauge theory renormalization constants fr om the low-energy limit of string theory. The Bern-Kosower method, bas ed on an off-shell continuation of string theory amplitudes, and the c onstruction of low-energy string theory effective actions for gauge pa rticles, can both be understood in terms of strings interacting with b ackground gauge fields, and thus reproduce, in the low-energy limit, t he held theory results of the background field method. We present in p articular a consistent off-shell continuation of the one-loop gluon am plitudes in the open bosonic string that reproduces exactly the result s of the background field method in the Feynman gauge.