Cabibbo-Suppressed Decays of D^+ to pi^+ pi^0, K^+ K^0, and K^+ pi^0

TL;DR

This paper reports improved measurements of certain Cabibbo-suppressed decay modes of the D^+ meson, providing more precise branching fractions and setting an upper limit on a doubly suppressed decay.

Contribution

It presents new, more accurate branching fraction measurements for D^+ decays and the first upper limit for a specific doubly suppressed mode.

Findings

Measured Br(D^+ to pi^+ pi^0) = (1.3 +/- 0.2) x 10^-3

Measured Br(D^+ to ar{K}^0 K^+) = (5.2 +/- 0.6) x 10^-3

Set upper limit Br(D^+ to K^+ pi^0) < 4.2 x 10^-4

Abstract

Using a data sample corresponding to 13.7 fb^-1 collected with the CLEO II and II.V detectors, we report new branching fraction measurements for two Cabibbo-suppressed decay modes of the D^+ meson: Br(D^+ to pi^+ pi^0) = (1.3 +/- 0.2) x 10^-3 and Br(D^+ to \bar{K}^0 K^+) = (5.2 +/- 0.6) x 10^-3 which are significant improvements over past measurements. The errors include statistical and systematical uncertainties as well as the uncertainty in the absolute D^+ branching fraction scale. We also set the first 90% confidence level upper limit on the branching fraction of the doubly Cabibbo-suppressed decay mode Br(D^+ to K^+ pi^0) < 4.2 x 10^-4.