Search for CP Violation in the Decays D0 --> K- K+ and D0 --> pi- pi+

TL;DR

This study measures CP-violating asymmetries in D0 meson decays to K- K+ and pi- pi+ with unprecedented precision, finding results consistent with Standard Model expectations.

Contribution

It provides the most precise measurements to date of CP violation in these decay modes using a large dataset and novel correction techniques.

Findings

Measured CP asymmetries consistent with zero.

Achieved highest precision in these decay channels.

Results agree with Standard Model predictions.

Abstract

We measure CP-violating asymmetries of neutral charmed mesons in the modes D0 --> K- K+ and D0 --> pi- pi+ with the highest precision to date by using D0 --> K- pi+ decays to correct detector asymmetries. An analysis of 385.8 fb-1 of data collected with the BaBar detector yields values of aCP(KK) = (0.00 +/- 0.34 (stat.) +/- 0.13 (syst.))% and aCP(pipi) = (-0.24 +/- 0.52 (stat.) +/- 0.22 (syst.))%, which agree with Standard Model predictions.