Odderon and spin dependence of high energy proton-proton scattering

The odderon is a latecomer to the family of Regge polesand, to date, there is not any firm experimental evidence forit. It is the putative negative charge conjugation partner tothe Pomeron, the dominant Regge singularity at high energy.The exact nature of the Pomeron is even now not well un-derstood. Two aspects are virtually certain, almost by defi-nition: ~1! it is a singularity, no doubt more complicated thana simple pole, in the t-channel angular momentum plane thatlies at J51 when the momentum transfer t50, and ~2! it hascharge conjugation C511, signature (21)