Measurement of the difference of CP-violating asymmetries in D0 -> K+K- and D0 ->pi+pi- decays at CDF

TL;DR

This paper measures the difference in CP-violating asymmetries between D0 decays to K+K- and pi+pi- using proton-antiproton collision data, providing evidence for CP violation in charm decays.

Contribution

It presents the first measurement of the CP asymmetry difference in D0 decays at Fermilab, supporting evidence for CP violation in charm quark decays.

Findings

Measured Delta Acp = -0.62% with statistical and systematic uncertainties.

Result differs from zero by 2.7 standard deviations, indicating potential CP violation.

Supports similar findings in proton-proton collision experiments.

Abstract

We report a measurement of the difference (Delta Acp) between time-integrated CP--violating asymmetries in D0-> K+ K- and D0-> pi+pi- decays reconstructed in the full data set of proton-antiproton collisions collected by the Collider Detector at Fermilab, corresponding to 9.7 fb-1 of integrated luminosity. The strong decay D*+->D0 pi+ is used to identify the charm meson at production as D0 or anti-D0. We measure Delta Acp = [-0.62 +- 0.21 (stat) +- 0.10 (syst)] %, which differs from zero by 2.7 Gaussian standard deviations.This result supports similar evidence for CP violation in charm-quark decays obtained in proton-proton collisions.