D. M. Asner

Branching fraction and photon energy spectrum for b → sγ

We have measured the branching fraction and photon energy spectrum for the radiative penguin process b-->s gamma. We find Beta(b-->s gamma) = (3.21+/-0.43+/-0.27(+0.18)(-0.10))x10(-4), where the errors are statistical, systematic, and from theory corrections. We obtain first and second moments of the photon energy spectrum above 2.0 GeV, = 2.346+/-0.032+/-0.011 GeV, and -(2) = 0.0226+/-0.0066+/-0.0020 GeV(2), where the errors are statistical and systematic. From the first moment, we obtain (in the modified minimal subtraction renormalization scheme, to order 1/M(3)(B) and beta(0)alpha(2)(s)) the heavy quark effective theory parameter Lambda = 0.35+/-0.08+/-0.10 GeV.

Resonance structure of {tau}{sup -}{yields}K{sup -}{pi}{sup +}{pi}{sup -}{nu}{sub {tau}} decays

Using a sample of 4.7/fb integrated luminosity accumulated with the CLEO II detector at the Cornell Electron Storage Ring (CESR), we investigate the mass spectrum and resonant structure in tau->Kpipi decays. We measure the relative fractions of K1(1270) and K1(1400) resonances in these decays, as well as the K1 masses and widths. Our fitted K1 resonances are somewhat broader than previous hadroproduction measurements, and in agreement with recent LEP results from tau decay. The larger central value of our measured width supports models which attribute the small tau->Kpipi branching fraction to larger K1 widths than are presently tabulated. We also determine the Ka-Kb mixing angle theta_K.

Measurement of B({lambda}{sub c}{sup +}{yields}pK{sup -}{pi}{sup +})

The /c->pKpi yield has been measured in a sample of two-jet continuum events containing a both an anticharm tag (Dbar) as well as an antiproton (e+e- -> Dbar pbar X), with the antiproton in the hemisphere opposite the Dbar. Under the hypothesis that such selection criteria tag e+e- -> Dbar pbar (/c) X events, the /c->pkpi branching fraction can be determined by measuring the pkpi yield in the same hemisphere as the antiprotons in our Dbar pbar X sample. Combining our results from three independent types of anticharm tags, we obtain B(/c->pKpi)=(5.0+/-0.5+/-1.2)%