A search for CP violation and a measurement of the relative branching fraction in D+ -> KKpi decays

TL;DR

This paper searches for CP violation in specific D+ meson decays and measures the relative branching fraction, finding no significant CP asymmetry and providing precise decay rate ratios.

Contribution

It provides the first measurement of CP asymmetry in D+ -> KKpi decays and refines the relative branching fraction with reduced uncertainties.

Findings

No significant CP violation observed.

Measured relative branching fraction is (10.7 +/- 0.1 (stat.) +/- 0.2 (syst.))%.

Results are consistent with Standard Model predictions.

Abstract

We report on a search for the CP asymmetry in the singly Cabibbo-suppressed decays D+ -> KKpi and in the resonant decays D+ -> phipi and D+ -> KstarK based on a data sample of 79.9 fb^-1 recorded by the BABAR detector. We use the Cabibbo-favored Ds -> KKpi branching fraction as normalization in the measurements to reduce systematic uncertainties. The CP asymmetries obtained are A_{CP}(KKpi) = (1.4 +/- 1.0 (stat.) +/- 0.8 (syst.) x 10^-2, A_{CP}(phi pi) = (0.2 +/- 1.5 (stat.) +/- 0.6 (syst.) x 10^-2, and A_{CP}(Kstar K) = (0.9 +/- 1.7 (stat.) +/- 0.7 (syst.) x 10^-2. The relative branching fraction Gamma(D+ -> KKpi)/Gamma(D+ -> Kpipi) is also measured and is found to be (10.7 +/- 0.1 (stat.) +/- 0.2 (syst.) x 10^-2.