A correction to the Hamiltonian of the QCD string with quarks due to the rigidity term

The correction to the Hamiltonian of a quark-antiquark system due to the rigidity term in the action of the gluodynamics string is found using the action obtained by D. V. Antonov et al., Mod. Phys. Lett. A 11, 1905 (1996) with the Hamiltonian obtained by A. Yu. Dubin ct al., Phys. At. Nucl. 56, 1745 (1993); Phys. Lett. B 323, 41 (1994) and E. L. Gubankova and A. Yu. Dubin, Phys. Lett. B 334, 180 (1994); preprint ITEP 62-94. This correction contains additional contributions to the orbital momentum of the system and several higher derivative operators. The resulting Hamiltonian is used to evaluate the rigid-string-induced term in the Hamiltonian of the relativistic quark model for the case of large masses of the quark and antiquark. (C) 1997 American Institute of Physics.