Measurement of the charge asymmetry in B[superscript ±]→ϕK[superscript ±] and search for B[superscript ±]→ϕπ[superscript ±] decays

Abstract

The CP -violating charge asymmetry in B[superscript ±]→ϕK[superscript ±] decays is measured in a sample of pp collisions at 7 TeV centre-of-mass energy, corresponding to an integrated luminosity of 1.0 fb[superscript −1] collected by the LHCb experiment. The result is A[subscript CP](B[superscript ±]→ϕK[superscript ±]) = 0.022±0.021±0.009, where the first uncertainty is statistical and the second systematic. In addition, a search for the B[superscript ±]→ϕπ[superscript ±] decay mode is performed, using the B[superscript ±]→ϕK[superscript ±] decay rate for normalization. An upper limit on the branching fraction B(B[superscript ±]→ϕπ[superscript ±]) <1.5×10−7 is set at 90% confidence level.