Multivalued Fields on the Complex Plane and Braid Group Statistics
  We study in this paper a theory of free anyons associated to free conformal field theories defined on Riemann surfaces with a discrete and nonabelian group of authomorphisms. The particles are exchanged according to a nonabelian statistics, in which the $R-$matrix satisfy a multiparametric generalization of the usual Yang$-$Baxter equations. 
Franco Ferrari