Measurement of direct CP violation parameters in B^+/- -> J/ψK^+/- and B^+/- ->J/psi pi^+/- decays with 10.4 fb^-1 of Tevatron data
Résumé
We present a measurement of the direct CP-violating charge asymmetry in B^+- mesons decaying to J/psi K^+- and J/psi pi^+- where J/psi decays to mu^+ mu^-, using 10.4 fb^-1 of proton-antiproton collisions collected by the D0 detector during Run II at the Fermilab Tevatron Collider. A difference in the yield of B^- and B^+ mesons in these decays is found by fitting to the difference between their reconstructed invariant mass distributions resulting in asymmetries of ajpk = [ 0.59 +/- 0.36 ]%, which is the most precise measurement to date, and ajppi = [ -4.2 +/- 4.8 ]%. Both measurements are consistent with standard model predictions.
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