SPINOR AND ISOSPINOR STRUCTURE OF RELATIVISTIC PARTICLE PROPAGATORS

Representations by means of path integrals are used to find spinor and isospinor structure of relativistic particle propagators in external fields. For Dirac propagator in an external electromagnetic field all grassmannian integrations are performed and a general result is presen ted via a bosonic path integral. The spinor structure of the integrand is given explicitly by its decomposition in the independent gamma-mat rix structures. Similar technique is used to get the isospinor structu re of the scalar particle propagator in an external non-Abelian field.