289 research outputs found

    Observation of the Ξc+\Xi_c^+ Charmed Baryon Decays to Σ+Kπ+\Sigma^+ K^-\pi^+, Σ+Kˉ0\Sigma^+ \bar{K}^{*0}, and ΛKπ+π+\Lambda K^-\pi^+\pi^+

    Full text link
    We have observed two new decay modes of the charmed baryon Ξc+\Xi_c^+ into Σ+Kπ+\Sigma^+ K^-\pi^+ and Σ+Kˉ0\Sigma^+ \bar{K}^{*0} using data collected with the CLEO II detector. We also present the first measurement of the branching fraction for the previously observed decay mode Ξc+ΛKπ+π+\Xi_c^+\to\Lambda K^-\pi^+\pi^+. The branching fractions for these three modes relative to Ξc+Ξπ+π+\Xi_c^+\to\Xi^-\pi^+\pi^+ are measured to be 1.18±0.26±0.171.18 \pm 0.26 \pm 0.17, 0.92±0.27±0.140.92 \pm 0.27 \pm 0.14, and 0.58±0.16±0.070.58 \pm 0.16 \pm 0.07, respectively.Comment: 12 page uuencoded postscript file, postscript file also available through http://w4.lns.cornell.edu/public/CLN

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

    Full text link
    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

    Radiative Decay Modes of the D0D^{0} Meson

    Get PDF
    Using data recorded by the CLEO-II detector at CESR we have searched for four radiative decay modes of the D0D^0 meson: D0ϕγD^0\to\phi\gamma, D0ωγD^0\to\omega\gamma, D0KˉγD^0\to\bar{K}^{*}\gamma, and D0ρ0γD^0\to\rho^0\gamma. We obtain 90% CL upper limits on the branching ratios of these modes of 1.9×1041.9\times 10^{-4}, 2.4×1042.4\times 10^{-4}, 7.6×1047.6\times 10^{-4} and 2.4×1042.4\times 10^{-4} respectively.Comment: 15 page postscript file, postscript file also available through http://w4.lns.cornell.edu/public/CLN

    Measurement of the Mass Splittings between the bbˉχb,J(1P)b\bar{b}\chi_{b,J}(1P) States

    Full text link
    We present new measurements of photon energies and branching fractions for the radiative transitions: Upsilon(2S)->gamma+chi_b(J=0,1,2). The masses of the chi_b states are determined from the measured radiative photon energies. The ratio of mass splittings between the chi_b substates, r==(M[J=2]-M[J=1])/(M[J=1]-M[J=0]) with M the chi_b mass, provides information on the nature of the bbbar confining potential. We find r(1P)=0.54+/-0.02+/-0.02. This value is in conflict with the previous world average, but more consistent with the theoretical expectation that r(1P)<r(2P); i.e., that this mass splittings ratio is smaller for the chi_b(1P) triplet than for the chi_b(2P) triplet.Comment: 11 page postscript file, postscript file also available through http://w4.lns.cornell.edu/public/CLN

    Studies of the Cabbibo-Suppressed Decays D+π0+νD^+ \to \pi^0 \ell^+ \nu and D+ηe+νeD^+ \to \eta e^+ \nu_e

    Full text link
    Using 4.8 fb1^{-1} of data taken with the CLEO II detector, the branching fraction for the Cabibbo-suppressed decay D+π0+νD^+\to\pi^0\ell^+\nu measured relative to the Cabibbo favored decay D+K0ˉ+νD^+\to\bar{K^0}\ell^+\nu is found to be 0.046±0.014±0.0170.046\pm 0.014\pm 0.017. Using VcsV_{cs} and VcdV_{cd} from unitarity constraints, we determine f+π(0)/f+K(0)2=0.9±0.3±0.3| f_+^{\pi}(0)/f_+^K(0)|^2=0.9\pm 0.3\pm 0.3 We also present a 90% confidence level upper limit for the branching ratio of the decay D+ηe+νeD^+ \to \eta e^+\nu_e relative to that for D+π0e+νeD^+ \to \pi^0 e^+\nu_e of 1.5.Comment: 10 page postscript file, postscript file also available through http://w4.lns.cornell.edu/public/CLN

    Search for leptophobic Z ' bosons decaying into four-lepton final states in proton-proton collisions at root s=8 TeV

    Get PDF
    Peer reviewe

    Search for black holes and other new phenomena in high-multiplicity final states in proton-proton collisions at root s=13 TeV

    Get PDF
    Peer reviewe

    Search for heavy resonances decaying into a vector boson and a Higgs boson in final states with charged leptons, neutrinos, and b quarks

    Get PDF
    Peer reviewe

    Search for high-mass diphoton resonances in proton-proton collisions at 13 TeV and combination with 8 TeV search

    Get PDF
    Peer reviewe

    Measurements of differential production cross sections for a Z boson in association with jets in pp collisions at root s=8 TeV

    Get PDF
    Peer reviewe
    corecore