Measurement of the $C\hat{A}\P$ asymmetry in $B^{+}\to K^{+}\hat{I}{¼}^{+}\hat{I}{¼}^{-}$ decays

Abstract

A measurement of the $C\hat{A}\P$ asymmetry in $B^{+}\to K^{+}\hat{I}{¼}^{+}\hat{I}{¼}^{-}$ 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 centre-of-mass energy of 7 TeV. The measurement is performed in seven bins of $\hat{I}{¼}^{+}\hat{I}{¼}^{-}$ invariant mass squared in the range $0.05<q^2<22.00\mathrm{Ge}{\mathrm{V}}^2/c^4$, excluding the $J/\ddot{I}ˆ$ and $\ddot{I}ˆ(2S)$ resonance regions. Production and detection asymmetries are corrected for using the $B^{+}\to J/\ddot{I}ˆK^{+}$ decay as a control mode. Averaged over all the bins, the $C\hat{A}\P$ asymmetry is found to be ${\mathcal{A}}_{C\hat{A}\P }=0.000\pm 0.033(stat.)\pm 0.005(syst.)\pm 0.007(J/\ddot{I}ˆK^{+})$, where the third uncertainty is due to the $C\hat{A}\P$ asymmetry of the control mode. This is consistent with the Standard Model prediction.

16 pages including author list, 2 figures