The decay branching fractions of the three narrow Upsilon resonances to mu(+)mu(-) have been measured by analyzing about 4.3 fb(-1) e(+)e(-) data collected with the CLEO III detector. The branching fraction B(Upsilon(1S)-->mu(+)mu(-))=(2.49+/-0.02+/-0.07)% is consistent with the current world average, but B(Upsilon(2S)-->mu(+)mu(-))=(2.03+/-0.03+/-0.08)% and B(Upsilon(3S)-->mu(+)mu(-))=(2.39+/-0.07+/-0.10)% are significantly larger than prior results. These new muonic branching fractions imply a narrower total decay width for the Upsilon(2S) and Upsilon(3S) resonances and lower other branching fractions that rely on these decays in their determination.

Using the CLEO detector at the Cornell Electron-positron Storage Ring, we have measured the scaled momentum spectra, d=dx p , and the inclusive production cross sections of the charm mesons D , D 0 , D ? , and D ?0 in e e ÿ annihilation at about 10.5 GeV center of mass energy, excluding the decay products of B mesons. The statistical accuracy and momentum resolution are superior to previous measurements at this energy.

We report on the observation of the eta(')(c)(2(1)S0), the radial excitation of the eta(c)(1(1)S0) ground state of charmonium, in the two-photon fusion reaction gammagamma-->eta(')(c)-->K(0)(S)K+/-pi(-/+) in 13.6 fb(-1) of CLEO II/II.V data and 13.1 fb(-1) of CLEO III data. We obtain M(eta(')(c))=3642.9+/-3.1(stat)+/-1.5(syst) MeV and M(eta(c))=2981.8+/-1.3(stat)+/-1.5(syst) MeV. The corresponding values of hyperfine splittings between 1S0 and 3S1 states are DeltaM(hf)(1S)=115.1+/-2.0 MeV and DeltaM(hf)(2S)=43.1+/-3.4 MeV. Assuming that the eta(c) and eta(')(c) have equal branching fractions to K(S)Kpi, we obtain Gamma(gammagamma)(eta(')(c))=1.3+/-0.6 keV.

We present the first evidence for the production of Υ(1D) states in the four-photon cascade, Υ(3S) → γχ b (2P ), χ b (2P ) → γΥ(1D), Υ(1D) → γχ b (1P ), χ b (1P ) → γΥ(1S), followed by the Υ(1S) annihilation into e + e − or µ + µ − . The signal has a significance of 10.2 standard deviations. The measured product branching ratio for these five decays, (2.5 ± 0.5 ± 0.5) • 10 −5 , is consistent with the theoretical estimates. The data are dominated by the production of one Υ(1D) state consistent with the J = 2 assignment. Its mass is determined to be (10161.1 ± 0.6 ± 1.6) MeV, which is consistent with the predictions from potential models and lattice QCD calculations.We also searched for Υ(3S) → γχ b (2P ), χ b (2P ) → γΥ(1D), followed by either Υ(1D) → ηΥ(1S) or Υ(1D) → π + π − Υ(1S). We find no evidence for such decays and set upper limits on the product branching ratios.

We report on a search for the recently reported X(3872) state using 15.1 fb(-1) of e(+)e(-) data taken in the sqrt[s] = 9.46-11.30 GeV region. Separate searches for the production of the X(3872) in untagged gammagamma fusion and e(+)e(-) annihilation following initial state radiation are made by taking advantage of the unique angular correlation between the leptons from the decay J/psi --> l(+)l(-) in X(3872) decay to pi(+)pi(-)J/psi. No signals are observed in either case, and 90% confidence upper limits are established as (2J+1)Gamma(gammagamma)(X(3872))B(X --> pi(+)pi(-)J/psi) < 12.9 eV and Gamma(ee)(X(3872))B(X- -> pi(+)pi(-)J/psi) < 8.3 eV.