How to measure Pomeron phase and discover odderon at HERA and RHIC

We suggest to measure Pomeron phase and discover odderon via the measurement of charge asymmetry of pions in the diffractive processes $ep\to e\pi^+\pi^- p$, $eA\to e\pi^+\pi^- A$ and in the processes $AA\to AA\pi^+\pi^-$ with two rapidity gaps.