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

Abstract

A study of B±→J/ψπ± and B±→ψ(2S)π± decays is performed with data corresponding to 0.37 fb−1 of proton-proton collisions at √s=7 TeV. 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 AJ/ψπCP=0.005±0.027±0.011andAψ(2S)πCP=0.048±0.090±0.011 with no evidence of direct CP violation seen.