Abstrakt
We measure the direct CP-violating parameter A(CP) for the decay of the charged charm meson, D+ -> K-pi(+)pi(+)(and charge conjugate), using the full 10.4 fb(-1) sample of p (p) over bar collisions at root s = 1.96 TeV collected by the D0 detector at the Fermilab Tevatron collider. We extract the raw reconstructed charge asymmetry by fitting the invariant mass distributions for the sum and difference of charge-specific samples.
This quantity is then corrected for detector-related asymmetries using data-driven methods and for possible physics asymmetries (from B. D processes) using input from Monte Carlo simulation.
We measure A(CP) =[-0.16 +/- 0.15(stat) +/- 0.09(syst)] %, which is consistent with zero, as expected from the standard model prediction of CP conservation, and is the most precise measurement of this quantity to date.