Measurement of the Bˉ→Dℓνˉ\bar{B}\to D\ell\bar{\nu} Partila Width and Form Factor Parameters

We have studied the decay $\bar{B} \to D\ell\bar{\nu}$, where $\ell=e or \mu$. From a fit to the differential decay rate $d\Gamma/dw$ we measure the rate normalization ${\cal F}_D(1)|V_{cb}|$ and form factor slope $\hat{\rho}^2_D$, and, using measured values of $\tau_B$, find $\Gamma(\bar{B} \to D\ell\bar{\nu}) = (12.0 \pm 0.9 \pm 2.1) ns^{-1}$. The resulting branching fractions are ${\cal B}(\bar{B}^0 \to D^+\ell^-\bar{\nu})=(1.87 \pm 0.15 \pm 0.32)$ and ${\cal B}(B^- \to D^0\ell^-\bar{\nu})=(1.94 \pm 0.15 \pm 0.34)$. The form factor parameters are in agreement with those measured in $\bar{B} \to D^*\ell\bar{\nu}$ decays, as predicted by heavy quark effective theory.Comment: 11 pages, postscript file also available through http://w4.lns.cornell.edu/public/CLN

Measurement of the Branching Ratios for the Decays of Ds+→ηπ+,η′π+,ηρ+D_{s}^{+}\to \eta\pi^{+}, \eta^{'}\pi^{+}, \eta\rho^{+}, and eta′ρ+eta^{'}\rho^{+}

Using a data sample with integrated luminosity of about 3.9 fb^{-1} collected in e+ e- annihilation with the CLEO-II detector at the Cornell Electron Storage Ring, we have measured the branching ratios for the decay modes Ds -> (eta, eta') pi and Ds -> (eta, eta') rho relative to Ds -> phi pi. These decay modes are among the most common hadronic decays of the Ds's and can be related by factorization to the semileptonic decays Ds -> (eta,eta') l nu. The results obtained are compared with previous CLEO results and with the branching ratios measured for the related semileptonic decays. We also report results on the Cabibbo-suppressed decays of the D+ to the same final states.Comment: 18 page postscript file, postscript file also available through http://w4.lns.cornell.edu/public/CLN

Tau Neutrino Helicity from h±h^{\pm} Energy Correlations

We report a measurement of the magnitude of the tau neutrino helicity from tau-pair events taken with the CLEO detector at the CESR electron-positron storage ring. Events in which each tau undergoes the decay tau -> h nu, with h a charged pion or kaon, are analyzed for energy correlations between the daughter hadrons, yielding |xi| = 2*|h_nu| = 1.03 +/- 0.06 +/- 0.04, with the first error statistical and the second systematic.Comment: 11 pages, postscript file also available through http://w4.lns.cornell.edu/public/CLN

Search for the Decay τ−→4pi−3π+(π0)ντ\tau^{-}\to 4pi^{-}3\pi^{+}(\pi^{0})\nu_{\tau}

We have searched for the decay of the tau lepton into seven charged particles and zero or one pi0. The data used in the search were collected with the CLEO II detector at the Cornell Electron Storage Ring (CESR) and correspond to an integrated luminosity of 4.61 fb^(-1). No evidence for a signal is found. Assuming all the charged particles are pions, we set an upper limit on the branching fraction, B(tau- -> 4pi- 3pi+ (pi0) nu_tau) < 2.4 x 10^(-6) at the 90% confidence level. This limit represents a significant improvement over the previous limit.Comment: 9 page postscript file, postscript file also available through http://w4.lns.cornell.edu/public/CLN

Observation of Exclusive Two-Body B Decays to Kaons and Pions

We have studied two-body charmless hadronic decays of B mesons into the final states $\pi\pi$, $K \pi$, and $KK$. Using 3.3 million $B\bar{B}$ pairs collected with the CLEO-II detector, we have made the first observation of the decays $B^0\to K^+\pi^-$, $B^+\to K^0\pi^+$, and the sum of $B^+ \to \pi^+\pi^0$ and $B^+ \to K^+\pi^0$ decays (an average over charge-conjugate states is always implied). We place upper limits on branching fractions for the remaining decay modes.Comment: 9 page postscript file, postscript file also available through http://w4.lns.cornell.edu/public/CLN

Investigation of Semileptonic BB Meson Decay to P-Wave Charm Mesons

We have studied semileptonic $B$ meson decays with a P-wave charm meson in the final state using 3.29 x 10^6 B\bar{B} events collected by the CLEO~II detector at the Cornell Electron-positron Storage Ring. We find a value for the exclusive semileptonic product branching fraction: Br(B^- -> D_1^0 l^- \bar{\nu}) x Br(D_1^0 -> D^{*+}\pi^-) = (0.373 \pm 0.085 \pm 0.052 \pm 0.024)% and an upper limit for Br(B^- -> D_2^{*0} l^- \bar{\nu}) x Br(D_2^{*0} -> D^{*+}\pi^-) < 0.16%$ (90% C.L.). These results indicate that at least 20% of the total B^- semileptonic rate is unaccounted for by the observed exclusive decays, B^- -> D^0 l^- \bar{\nu}, B^- -> D^{*0} l^- \bar{\nu}, B^- -> D_1^0 l^- \bar{\nu}, and B^- -> D_2^{*0} l^- \bar{\nu}.Comment: 10 page postscript file, postscript file also available through http://w4.lns.cornell.edu/public/CLN

Limit on the Two-Photon Production of the Glueball Candidate fJ(2220)f_{J}(2220) at CLEO

We use the CLEO detector at the Cornell electron-positron storage ring, CESR, to search for the two-photon production of the glueball candidate f_J(2220) in its decay to K_s K_s. We present a restrictive upper limit on the product of the two-photon partial width and the K_s K_s branching fraction. We use this limit to calculate a lower limit on the stickiness, which is a measure of the two-gluon coupling relative to the two-photon coupling. This limit on stickiness indicates that the f_J(2220) has substantial glueball content.Comment: 9 page postscript file, postscript file also available through http://w4.lns.cornell.edu/public/CLN

Search for the Decays B^0 -> D^{(*)+} D^{(*)-}

Using the CLEO-II data set we have searched for the Cabibbo-suppressed decays B^0 -> D^{(*)+} D^{(*)-}. For the decay B^0 -> D^{*+} D^{*-}, we observe one candidate signal event, with an expected background of 0.022 +/- 0.011 events. This yield corresponds to a branching fraction of Br(B^0 -> D^{*+} D^{*-}) = (5.3^{+7.1}_{-3.7}(stat) +/- 1.0(syst)) x 10^{-4} and an upper limit of Br(B^0 -> D^{*+} D^{*-}) D^{*\pm} D^\mp and B^0 -> D^+ D^-, no significant excess of signal above the expected background level is seen, and we calculate the 90% CL upper limits on the branching fractions to be Br(B^0 -> D^{*\pm} D^\mp) D^+ D^-) < 1.2 x 10^{-3}.Comment: 12 page postscript file also available through http://w4.lns.cornell.edu/public/CLNS, submitted to Physical Review Letter

Study of the B^0 Semileptonic Decay Spectrum at the Upsilon(4S) Resonance

We have made a first measurement of the lepton momentum spectrum in a sample of events enriched in neutral B's through a partial reconstruction of B0 --> D*- l+ nu. This spectrum, measured with 2.38 fb**-1 of data collected at the Upsilon(4S) resonance by the CLEO II detector, is compared directly to the inclusive lepton spectrum from all Upsilon(4S) events in the same data set. These two spectra are consistent with having the same shape above 1.5 GeV/c. From the two spectra and two other CLEO measurements, we obtain the B0 and B+ semileptonic branching fractions, b0 and b+, their ratio, and the production ratio f+-/f00 of B+ and B0 pairs at the Upsilon(4S). We report b+/b0=0.950 (+0.117-0.080) +- 0.091, b0 = (10.78 +- 0.60 +- 0.69)%, and b+ = (10.25 +- 0.57 +- 0.65)%. b+/b0 is equivalent to the ratio of charged to neutral B lifetimes, tau+/tau0.Comment: 14 page, postscript file also available at http://w4.lns.cornell.edu/public/CLN