The structure of a gluon string

Equations are derived for the mean fields in a gluon string which couples a quark to an antiquark. A string solution does not exist within the framework of the perturbation approach. A model which takes nonperturbation effects into account is presented; it leads to a string solution in which the gluoelectric field directed along the string is surrounded by a circular gluomagnetic field. The fields are localized in a region with a transverse dimension of the order of the confinement radius. The strain coefficient and the parameters characterizing the field distribution are estimated.