On the evaluation of the evolution operator Z_Reg(R_2,R_1) in the Diakonov-Petrov approach to the Wilson loop

We evaluate the evolution operator Z_Reg(R_2,R_1) introduced by Diakonov and Petrov for the definition of the Wilson loop in terms of a path integral over gauge degrees of freedom. We use the procedure suggested by Diakonov and Petrov (Phys. Lett. B224 (1989) 131) and show that the evolution operator vanishes.