Measurement of the D+ and Ds+ decays into K+K-K+

TL;DR

This paper reports the first clear observation of specific suppressed charm meson decays, measuring their relative branching ratios using high-statistics photoproduction data from the Fermilab FOCUS experiment.

Contribution

It provides the first measurements of the branching ratios for D+ and Ds+ decays into K+K-K+ relative to other decay modes, using a large dataset from photoproduction.

Findings

First observation of D+ --> K-K+K+ decay.

First observation of Ds+ --> K-K+K+ decay.

Measured relative branching ratios with statistical and systematic uncertainties.

Abstract

We present the first clear observation of the doubly Cabibbo suppressed decay D+ --> K-K+K+ and the first observation of the singly Cabibbo suppressed decay Ds+ --> K-K+K+. These signals have been obtained by analyzing the high statistics sample of photoproduced charm particles of the FOCUS(E831) experiment at Fermilab. We measure the following relative branching ratios: Gamma(D+ --> K-K+K+)/Gamma(D+ --> K-pi+pi+) = (9.49 +/- 2.17(statistical) +/- 0.22(systematic))x10^-4 and Gamma(Ds+ --> K-K+K+)/Gamma(Ds+ --> K-K+pi+) = (8.95 +/- 2.12(statistical) +2.24(syst.) -2.31(syst.))x10^-3.