Measurements of the branching fractions and CP asymmetries of B± ^→J/ψπ± and B± ^{→ψ(2S)π±} decays

A study of B ^±→J/ψπ ^± and B ^±→ψ(2S)π ^± decays is performed with data corresponding to 0.37fb ^-1 of proton-proton collisions at √s=7TeV. Their branching fractions are found to be B(B ^±→J/ψπ ^±)=(3.88±0. 11±0.15)×10 ^-5andB(B ^±→ψ(2S) π ^±)=(2.52±0.26±0.15)×10 ^-5,where the first uncertainty is related to the statistical size of the sample and the second quantifies systematic effects. The measured CP asymmetries in these modes are ACPJ/ψπ=0.005±0.027±0. 011andACPψ(2S)π=0.048±0.090±0.011 with no evidence of direct CP violation seen.