CLEO Results: B Decays

TL;DR

The CLEO Collaboration has improved the precision of CKM matrix element measurements by reducing uncertainties in nonperturbative QCD parameters through new B decay data, including B -> s gamma and other charmless decays.

Contribution

This work presents new measurements of B -> s gamma decays and CKM elements Vcb and Vub, along with initial results from CLEO III on various B decay modes, advancing understanding of nonperturbative QCD effects.

Findings

New measurements of B -> s gamma branching fraction and photon spectrum.

First results from CLEO III on B -> K pi, pi pi, and K Kbar decays.

Plans for future data collection in the charm threshold region.

Abstract

Measurements of many Standard Model constants are clouded by uncertainties in nonperturbative QCD parameters that relate measurable quantities to the underlying parton-level processes. Generally these QCD parameters have been obtained from model calculations with large uncertainties that are difficult to quantify. The CLEO Collaboration has taken a major step towards reducing these uncertainties in determining the CKM matrix elements Vcb and Vub using new measurements of the branching fraction and photon energy spectrum of B -> s gamma decays. This report includes: the new CLEO measurements of B -> s gamma decays, Vcb, and Vub; the first results from CLEO III data -- studies of B -> K pi, pi pi, and K Kbar decays; mention of some other recent CLEO B decay results; and plans for operating CESR and CLEO in the charm threshold region.