WKB quantization of reggeon compound states in high-energy QCD

We study the spectrum of the reggeized gluon compound states in high-energy QCD. The energy of the states depends on the total set of quantum numbers whose values are constrained by the quantization conditions. To establish their explicit form we apply the methods of nonlinear WKB analysis to the Schrödinger equation for the $N$ reggeon state in the separated coordinates. We solve the quantization conditions for the N=3 reggeon states in the leading order of the WKB expansion and observe a good agreement of the obtained spectrum of quantum numbers with available exact solutions.