Pomeron/Odderon Interference in Diffractive Meson Pairs Production

We study Pomeron-Odderon interference effects giving rise to charge and single-spin asymmetries in diffractive electroproduction of a ${\pi }^{+}{\pi }^{-}$ pair. The final state interactions and the role of $f_0$ meson are discussed. The absence of $f_0$ signal in the charge asymmetry observed by HERMES may be due to the smalness of its quark component.