Pomeron-Odderon interference effects in electroproduction of two pions

We study Pomeron-Odderon interference effects giving rise to charge and single-spin asymmetries in diffractive electroproduction of a π π pair. We calculate these asymmetries originating from both longitudinal and transverse polarizations of the virtual photon, in the framework of QCD and in the Born approximation, in a kinematical domain accessible to HERA experiments. We predict a sizable charge asymmetry with a characteristic dependence on the invariant mass of the π π pair, which makes this observable very important for establishing the magnitude of the Odderon exchange in hard processes. The single spin asymmetry turns out to be rather small. We briefly discuss future improvements of our calculations and their possible effects on the results. 1 Unité mixte C7644 du CNRS.