| Resumen |
We present a measurement of the semileptonic mixing asymmetry for B0 mesons, adsl, using two independent decay channels: B0→μ+D−X, with D−→K+π−π−; and B0→μ+D*−X, with D*−→D¯¯¯0π−, D¯¯¯0→K+π− (and charge conjugate processes). We use a data sample corresponding to 10.4 fb−1 of pp¯ collisions at s√=1.96 TeV, collected with the D0 experiment at the Fermilab Tevatron collider. We extract the charge asymmetries in these two channels as a function of the visible proper decay length of the B0 meson, correct for detector-related asymmetries using data-driven methods, and account for dilution from charge-symmetric processes using Monte Carlo simulation. The final measurement combines four signal visible proper decay length regions for each channel, yielding adsl=[0.68±0.45(stat)±0.14(syst)]%. This is the single most precise measurement of this parameter, with uncertainties smaller than the current world average of B factory measurements. |
