Search for direct CP violation in charged charmless B→PV decays

Measurements of C P asymmetry in charmless B → P V decays are presented, where P and V denote a pseudoscalar and a vector meson, respectively. Five different B → P V decays from four final states, B ± → π ± π + π − , B ± → K ± π + π − , B ± → K ± K + K − and B ± → π ± K + K − are analyzed. The measurements are based on a method that does not require full amplitude analyses, and are performed using proton-proton collision data at a center-of-mass energy of 13 TeV collected by LHCb between 2015 and 2018, corresponding to an integrated luminosity of 5.9     fb − 1 . In the π + π − P -wave, in the region dominated by the B ± → ρ ( 770 ) 0 K ± decay, a C P asymmetry of A C P = + 0.150 ± 0.019 ± 0.011 is measured, where the first uncertainty is statistical and the second is systematic. This is the first observation of C P violation in this process. For the other four decay channels, in regions dominated by the B ± → ρ ( 770 ) 0 π ± , B ± → ( ¯   ) K   ∗ ( 892 ) 0 π ± , B ± → ( ¯   ) K   ∗ ( 892 ) 0 K ± and B ± → ϕ ( 1020 ) K ± decays, C P asymmetries in the P -wave compatible with zero are measured.