Measurement of CP asymmetry in Cabibbo suppressed D0 decays

TL;DR

This paper reports a precise measurement of CP asymmetries in specific D0 meson decays, finding results consistent with no CP violation, thus testing the Standard Model's predictions in charm quark processes.

Contribution

First measurement of CP asymmetries in D0 -> K+K- and D0 -> pi+pi- decays using Belle data, with systematic corrections and high statistical precision.

Findings

Measured A_{CP}^{KK} = (-0.43 +- 0.30 +- 0.11)%

Measured A_{CP}^{pipi} = (+0.43 +- 0.52 +- 0.12)%

Results are consistent with no CP violation.

Abstract

We measure the CP-violating asymmetries in decays to the D0 -> K+K- and D0 -> pi+pi- CP eigenstates using 540 fb^{-1} of data collected with the Belle detector at or near the Upsilon(4S) resonance. Cabibbo-favored D0 -> K-pi+ decays are used to correct for systematic detector effects. The results, A_{CP}^{KK} = (-0.43 +- 0.30 +- 0.11)% and A_{CP}^{pipi} = (+0.43 +- 0.52 +- 0.12)%, are consistent with no CP violation.