Measurements of the branching fractions and CP asymmetries of B± →J/ψπ± 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 0.37fb -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. © 2012 CERN.