Observation of large CP violation and evidence for direct CP violation in B0 → π+ π- decays

The CP violation parameters in Bo → π +π- decay were investigated. The flavor of the accompanying B meson was identified by reconstructing B o→π+π- CP eigenstate. It was observed that the expected sensitivity was optimized using the ratio LR. The study showed that there was a direct CP violation with a significance at or greater than 3.2σ.