Measurement of the CP-violating phase $\beta$ in $B^0\to J/\psi {\pi }^{+}{\pi }^{-}$ decays and limits on penguin effects

LHCb collaboration, R. Aaij, B. Adeva +697

Time-dependent CP violation is measured in the $B^0\to J/\psi {\pi }^{+}{\pi }^{-}$ channel for each ${\pi }^{+}{\pi }^{-}$ resonant final state using data collected with an integrated luminosity of 3.0 f…