A Correction to the Hamiltonian of the QCD String with Quarks due to the   Rigidity Term
  A correction to the Hamiltonian of the quark-antiquark system, arising due to the rigidity term in the gluodynamics string effective action, is obtained. This correction contains additional contributions to the orbital momentum of the system and several higher derivative operators. With the help of the derived Hamiltonian a rigid string-induced term in the Hamiltonian of the relativistic quark model is evaluated for the case of large masses of a quark and antiquark. 
D.V.Antonov (Humboldt University, Berlin and ITEP, Moscow)