D. M. Coffman

Measurement of the Branching Fractions for D0 ---> pi- e+ electron-neutrino and D0 ---> K- e+ electron-neutrino and Determination of (V (c d) / V (c s))**2

Measurements of the exclusive branching fractions B(D^0→π^-e^+ν_e) and B(D^0→K^-e^+ν_e), using data collected at the ψ(3770) with the Mark III detector at the SLAC e^+e^- storage ring SPEAR, are used to determine the ratio of the Kobayashi-Maskawa matrix elements │V_(cd)/V_(cs)│^2 =0.057_(-0.015)^(+0.038)±0.005.

Resonant substructure in Kππ decays of charmed D mesons

Abstract Dalitz plot analyses of four Kππ decays of the D 0 and D + mesons are presented. The relative amounts of K ∗ π, Kϱ and non-resonant Kππ in each decay mode are determined, and isospin amplitudes and phases are derived. These results are compared with predictions from QCD. The K − π + π + mode has a non-uniform, non-resonant contribution; attempts to fit this distribution are described.

A search for exclusive penguin decays of B mesons

Abstract We have measured upper limits on branching fractions for rare exclusive decays of B mesons arising from one-loop diagrams in the standard model of electroweak interactions. We also obtain an upper limit for the lepton-number-violating decay B 0 → μ ± e ∓ .

Measurement of the isospin mass splitting Ξ+cΞ0c

Abstract Using the CLEO detector, we present a measurement of the mass of the charged charmed strange baryon Ξ + c and its neutral counterpart the Ξ 0 c . The Ξ + c is observed through its decay to Ξ - π + π + , and its mass is measured to be (2467±3±4) MeV. The isospin mass splitting of the Ξ c system is found to be M ( Ξ + c )- M ( Ξ 0 c )=(−5±4±1)MeV.

Measurement of the

We report a new measurement of the D∗ branching ratios, using data obtained with the Mark III detector at the e^+e^− storage ring SPEAR at s=4.14GeV. A fit to the recoil mass squared spectrum of D mesons reconstructed through the decay modes K^−π^+π^+ and K^−π^+ is used to extract the D^(∗+) → γD^+, π^0D^+, π^+D^0 and D^(∗0) → γD^0, π^0D^0 branching ratios.

D^*

We present a study of the radiative decay J/ψ→γOO in the γK + K − K + K − and γK + K − K S 0 K L 0 final states. A pseudoscalar state is observed in the OO invariant-mass spectrum at 2.22 GeV/c 2 with a width of 150 MeV/c 2 . The product branching ratios are B(J/ψ→γX)B(X→OO)=(3.3±0.8±0.5)×10 −4 for the MeV/c γK + K − K + K − mode and B(J/ψ→γX)B(X→OO)=(2.7±0.6±0.6)×10 −4 for the γK + K − K S 0 K L 0 mode. No evidence for 2 ++ states below 2.4 GeV/c 2 is found in this decay

Branching Ratios

Using the CLEO detector at the Cornell Electron Storage Ring (CESR), we have determined the ratio {Gamma}({ital D}{sub {ital s}}{sup +}{r arrow}{phi}{ital l}{sup +}{nu})/{Gamma}({ital D}{sub {ital s}}{sup +} {r arrow}{phi}{pi}{sup +})=0.49{plus minus}0.10{sub {minus}0.14}{sup +0.10}. We use this measurement to derive {ital B}({ital D}{sub {ital s}}{sup +}{r arrow}{phi}{pi}{sup +}).

Observation of a pseudoscalar state in J/ psi --> gamma phi phi near phi phi threshold.

We use a data sample of 2.8 × 10 6 produced τ-pair events, obtained with the CLEO II detector, to measure B(τ - Ⅵh - h + h - (π 0 )ν τ ), where h refers to either a charged π or K. These branching fractions are measured with samples of lepton-tagged and 3 vs 3 events. We find B(τ - Ⅵh - h + h - ν τ )=0.0951±0.0007±0.0020 and B(τ - Ⅵh - h + h - π 0 ν τ )=0.0423±0.0006±0.0022. We also measure B(τ - Ⅵωh - ν τ )=0.0195±0.0007±0.0011.

Determination of B(Ds+) via observation of Ds+l+1/2

Abstract Using the CLEO detector at the Cornell Electron Storage Ring, we have searched for two-photon production of charmonium in four-track final states. We have measured Γ γγ ( η c )=5.9 +2.1 −1.8 ±1.9 keV, and we have obtained 95% CL upper limits of Γ γγ ( X c 0 ) Γ γγ ( X c 2 )

Measurements of the decays tau(-) -> h(-)h(+)h(-)nu(tau) and tau(-) -> h(-)h(+)h(-)pi(0)nu(tau)

Using data taken with the CLEO II detector, we present the first full angular analysis in the color-suppressed modes B{sup 0} {yields} J/{psi} K*{sup 0} and B{sup +} {yields} J/{psi} K*{sup +}. This leads to a complete determination of the decay amplitudes of these modes. In addition, we update the branching fractions for B {yields} J/{psi} K and B {yields} J/{psi} K*.