Measurement of CP asymmetries in the decays B⁰→ K^*0μ⁺μ⁻ and B⁺→ K⁺μ⁺μ⁻

The direct CP asymmetries of the decays B0 → K∗0µ+µ− and B+ → K+µ+µ− are measured using pp collision data corresponding to an integrated luminosity of 3.0 fb−1 collected with the LHCb detector. The respective control modes B0 → J/ψK∗0 and B+ → J/ψK+ are used to account for detection and production asymmetries. The measurements are made in several intervals of µ+µ− invariant mass squared, with the φ(1020) and charmonium resonance regions excluded. Under the hypothesis of zero CP asymmetry in the control modes, the average values of the asymmetries are
ACP (B0 → K∗0µ+µ−) = −0.035 ± 0.024 ± 0.003 ,
ACP (B+ → K+µ+µ−) = 0.012 ± 0.017 ± 0.001 ,
where the first uncertainties are statistical and the second are due to systematic effects. Both measurements are consistent with the Standard Model prediction of small CP asymmetry in these decays.