The equations of motion for a classical color particle in background non-Abelian bosonic and fermionic fields

摘要

Based on the most general principles of reality, gauge and reparametrizationinvariance, a problem of constructing the action describing dynamics of aclassical color-charged particle interacting with background non-Abelian gaugeand fermion fields is considered. The cases of the linear and quadraticdependence of a Lagrangian on a background fermion field are discussed. It isshown that in both cases in general there exists an infinite number ofinteraction terms, which should be included in the Lagrangian in question. Froma simple iteration scheme, examples of the construction of the first fewgauge-covariant currents and sources induced by a moving particle withnon-Abelian charge are given. It is shown that these quantities, by a suitablechoice of parameters, exactly reproduce additional currents and sourcespreviously obtained in [Yu.A. Markov, M.A. Markova, Nucl. Phys. A 784 (2007)443] on the basis of heuristic considerations.