CONFIGURATIONAL STATISTICS OF STRINGS, FRACTALS AND POLYMER PHYSICS .2. NON-ABELIAN STRINGS

We give a systematic numerical analysis of Kibble's non-abelian strings. A new phase structure determined by three different scaling laws stresses the intrinsic complexity of this statistical system. We will propose, as the main reason for the third new region, a screening phenomenon from polymer physics, which was already present in the topologically trivial sector of the abelian situation. In fact, strings are shown to be "dense" polymers on the lattice. Non-abelian strings, just like the abelian ones, show a fractal nature which is strongly dependent on their own topology. The fractal dimension of topologically trivial non-abelian strings is very different from that of the abelian corresponding case. Global quantities, such as the probability of no return, show clear evidence of very diverging predictions of the model from the known random walk results. © 1990.