  The interference between the Pomeron and possible odderon mechanisms of
diffractive pi+pi- photoproduction results in charge asymmetry of the produced
pions. The observation of charge asymmetry of pions at moderate M_{pi+pi-} will
be an undoubted signal of odderon existence. To make numeral estimates more
definite, we limit ourselves by the region M_{pi+pi-} = 1.1 -- 1.5 GeV, where
in the odderon mechanism of dipion production, the production via single
f_2(1270) resonance is expected to be dominant. We find a very statistically
significant effect of the odderon induced charge asymmetry even with very
modest estimates for the f_2 photoproduction cross section (without referring
to any particular model of the odderon).

High Energy Physics - Phenomenology;High Energy Physics - Experiment