The dynamics of a light quark in the field of a static source (heavy-light meson) is studied using the nonlinear Dirac equation, derived recently. Special attention is paid to the contribution of the magnetic correlators and it is found that it yields a significant increase of string tension at intermediate distances. The spectrum of heavy-light mesons is computed taking into account this contribution and compared to experimental and lattice data.

• Received 20 June 2000

DOI:https://doi.org/10.1103/PhysRevD.62.094511