On the odderon intercept in QCD

The odderon singularity is studied in perturbative QCD in the framework of the Bartels-Kwieci'nski-Praszalowicz (BKP) equation. Arguments for the odderon intercept being exactly equal to unity are given. Besides, a variational method based on a complete system of one-gluon functions is presented. For the odderon, the highest intercept calculated by this method is $1-(N_c{\alpha }_s\mathrm{/}\pi )0.45$. Comparison to other calculations is shown.