Hard Pomeron-Odderon interference effects in the production of pi^+pi^-   pairs in high energy gamma-gamma collisions at the LHC
  We estimate the production of two meson pairs in high energy photon photon collisions produced in ultraperipheral collisions at LHC. We show that the study of charge asymmetries may reveal the existence of the perturbative Odderon and discuss the concrete event rates expected at the LHC. Sizable rates and asymmetries are expected in the case of proton-proton collisions and medium values of gamma-gamma energies \sqrt{s_{\gamma \gamma}} \approx 20GeV. Proton-proton collisions will benefit from a high rate due to a large effective gamma-gamma luminosity and ion-ion collisions with a somewhat lower rate from the possibility to trigger on ultraperipheral collisions and a reduced background from strong interactions. 
B. Pire, L. Szymanowski, F. Schwennsen, S. Wallon