FINITE-THICKNESS EFFECTS FOR A STRING WITH A GENERALIZED LAGRANGIAN

A stringlike soliton with finite transverse dimensions is compared wit h a string whose Lagrangian involves an additional term that takes int o account external curvature by using the gluon tube model as an examp le. An effective Lagrangian, which does not contain higher derivatives , is obtained for the soliton. This makes it possible to remove energy paradoxes that are characteristic of the string model whose Lagrangia n involves the external curvature squared.