A RANDOM SURFACE THEORY WITH NONTRIVIAL GAMMA(STRING)

We measure by Monte Carlo simulations gamma(string) for a model of random surfaces embedded in three dimensional Euclidean space-time. The action of the string is the usual Polyakov action plus an extrinsic curvature term. The system undergoes a phase transition at a finite value he of the extrinsic curvature coupling and at the transition point the numerically measured value of gamma(string)(lambda(c)) approximate to 0.27 +/- 0.06. This is consistent with gamma(string)(lambda(c)) = 1/4, i.e. equal to the first of the non-trivial values of gamma(string) between 0 and 1/2.