Measurement of the C P Asymmetry in B + → K + μ + μ − Decays

Abstract

A measurement of the CP asymmetry in Bþ ! Kþ þ decays is presented using pp collision data, corresponding to an integrated luminosity of 1:0 fb 1, recorded by the LHCb experiment during 2011 at a center-of-mass energy of 7 TeV. The measurement is performed in seven bins of þ invariant mass squared in the range 0:05 < q2 < 22:00 GeV2=c4, excluding the J=c and c ð2SÞ resonance regions. Production and detection asymmetries are corrected for using the Bþ ! J=c Kþ decay as a control mode. Averaged over all the bins, the CP asymmetry is found to be ACP ¼ 0:000 0:033 ðstatÞ 0:005 ðsystÞ 0:007 (J=c K), where the third uncertainty is due to the CP asymmetry of the control mode. This is consistent with the standard model prediction.