FRACTION OF THE GLUONIUM COMPONENT IN η′ AND η

It is interesting to determine the fraction of the gluonium component in η and η′ which has been under serious discussion for many years. Measurements on different decay and/or production modes were employed in literatures, thus larger uncertainties were unavoidable. In this paper we suggest to determine the mixing angles of η-η′-G using the data of semileptonic decays of D and Ds. We extract the mixing angles ϕ′, ϕG and the model parameters simultaneously. Thanks to the new measurements carried out by CLEO Collaboration and there are sufficient decay modes to determine both the model parameters and mixing angles. The mixing angles from data are ϕ′ = (41.5 ± 2.0)° and sin ϕG = 0.00 ± 0.36. Even though the central value of sin ϕG is still zero, an upper bound is set. Moreover, as suggested in literature, η(1405) is a glueball candidate whereas in our picture, η(1405) may be identified as G with glueonium being its main content. Using all the model-parameters obtained above, we estimate the branching ratios of [Formula: see text] where G is identified as η(1405).

QUANTUM-CORRELATED MEASUREMENTS RELATED TO THE DETERMINATION OF γ/ϕ3

Measurements of D0 meson strong-phase parameters in quantum-correlated [Formula: see text] decays by the CLEO collaboration are presented. These measurements play an important role in the determination of the unitarity triangle angle γ/ϕ3 from B-meson decays. Measurements of the strong-phase parameters for D0 → K0π+π-, D0 → K0 K+ K-, D0 → K- π+ π0, and D0 → K- π+ π+ π- decays are described along with their impact on the determination of γ/ϕ3.

HADRON SPECTROSCOPY WITH CLEO DATA

The CLEO collaboration will explore the charm sector starting 2003. It is foreseen to collect on the order of 6 million [Formula: see text] pairs, 300000 [Formula: see text] pair at threshold and one billion J/ψ decays. High precision charm data will enable us to validate upcoming lattice QCD calculations that are expected to produce 1-3% errors for some non-perturbative QCD quantities. Virtually background free, they will provide interesting decay mechanisms to explore light meson spectroscopy. The radiative J/ψ decays will be the first high statistics data set well suited for meson spectroscopy between 1600 and 3000 MeV. Together with the already existing data from the ϒ resonances, data sets for a large number of decay mechanisms will be available, which, combined, can be used to extract the nature of many resonances.

CLEO RESULTS: B DECAYS

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 γ decays. This report includes: the new CLEO measurements of b → s γ decays, |Vcb|, and |Vub|; the first results from CLEO III data - studies of B → Kπ, ππ, and [Formula: see text] decays; mention of some other recent CLEO B decay results; and plans for operating CESR and CLEO in the charm threshold region.

From factor ratio measurement in the decay Λc→Λ e+ ν

The hadronic current of the matrix element for the transition Λc→Λ e+ ν within the framework of HQET is parameterized in terms of two form factors. By studying the decay rate distribution in the space of the decay kinematic variables one can extract the ratio [Formula: see text] of the form factors. The first measurement1 of R was made by the CLEO collaboration in 1995. In this note we describe the study of the statistical and systematic errors for a 4.5 times larger data sample. The central value for R will be presented shortly.

$D^0 - \overline{D^0}$ Mixing and D0→K-π+π0 Resonant Substructure Results from CLEO

The CLEO Collaboration has an active charm physics effort underway using 14fb-1 of CLEO II and CLEO II.V data. A recent analysis of the time dependence of the 'wrong-sign' decay D0→K+ π- has placed limits on x′ and y′, the amplitudes that describe mixing in the D0 system. The 95% CL limits, with no assumptions about CP violation, are (1/2)x′2 < 0.041% and -5.8% < y′ < 1.0%. Measurements of D0 decay rates to CP eigenstates, D0→K- K+ and D0→π-π+, provide preliminary CP asymmetry measurements [Formula: see text] and [Formula: see text]. A third analysis provides the first preliminary evidence for the decay D0→K+π- π0. Finally, a new Dalitz analysis of the decay D0→K-π+ π0 gives preliminary evidence for several new resonance contributions in this decay and also requires the presence of a significant non-resonant component.

RECENT CLEO RESULTS ON CHARMED BARYONS

Using data recorded by the CLEO II and CLEO II.V detectors at CESR, we report new measurements of the [Formula: see text] and [Formula: see text] masses, and the first measurements of their intrinsic widths. The measured widths of these particles agree with the theoretical predictions. We also present a new measurement of the mass of the [Formula: see text] charmed baryon, observed by its decay into [Formula: see text], and the first observation of a new state which is identified as the [Formula: see text], the isospin partner of the previously discovered [Formula: see text] and [Formula: see text]. The quark model predicts many excited states of Λc and Σc baryons, some of which cannot, because of quantum mechanical conservations rules, decay via one pion to the ground state. We present results of a search for such states decaying via dipion decays into the ground state [Formula: see text] Recently, The CLEO collaboration also reported the existence of a pair of excited Ξc particles decaying into [Formula: see text]. These are thought to be orbitally excited Ξc' s with JP = 3/2-. Here we present a search for the analogous JP=1/2- particles, which are predicted to decay into [Formula: see text].

THE CLEO III DETECTOR

After a long shutdown in 1999, the CLEO Collaboration at Cornell University's Wilson Laboratory began taking data in 2000 using its third generation detector, CLEO III. Several improvements to the detector system have been made in order to take advantage of the possibility of unprecedented luminosities of well over 2×1033 expected from CESR, and to explore new territory in the physics of B mesons. These improvements include a new drift chamber, a four layer silicon vertex detector and a RICH detector. These features will be described, and its performance will be presented.

$\Lambda^+_c$ PRODUCTION, DECAY, AND LIFETIME RESULTS AT CLEO

Production, decay, and lifetime measurements of the [Formula: see text] are presented by the CLEO collaboration using e+e- annihilation data collected on or just below the ϒ(4S) resonance at CESR. These measurements provide insight into the dynamics of heavy-quark production and decay.