128 research outputs found

    Evidence for the Decay D0→K+π−π+π−D^0\to K^+ \pi^-\pi^+\pi^-

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    We present a search for the ``wrong-sign'' decay D0 -> K+ pi- pi+ pi- using 9 fb-1 of e+e- collisions on and just below the Upsilon(4S) resonance. This decay can occur either through a doubly Cabibbo-suppressed process or through mixing to a D0bar followed by a Cabibbo-favored process. Our result for the time-integrated wrong-sign rate relative to the decay D0 -> K- pi+ pi- pi+ is (0.0041 +0.0012-0.0011(stat.) +-0.0004(syst.))x(1.07 +-0.10)(phase space), which has a statistical significance of 3.9 standard deviations.Comment: 9 pages postscript, also available through http://w4.lns.cornell.edu/public/CLNS, submitted to PR

    Hadronic Mass Moments in Inclusive Semileptonic B Meson Decays

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    We have measured the first and second moments of the hadronic mass-squared distribution in B -> X_c l nu, for P(lepton) > 1.5 GeV/c. We find <M_X^2 - M_D[Bar]^2> = 0.251 +- 0.066 GeV^2, )^2 > = 0.576 +- 0.170 GeV^4, where M_D[Bar] is the spin-averaged D meson mass. From that first moment and the first moment of the photon energy spectrum in b -> s gamma, we find the HQET parameter lambda_1 (MS[Bar], to order 1/M^3 and beta_0 alpha_s^2) to be -0.24 +- 0.11 GeV^2. Using these first moments and the B semileptonic width, and assuming parton-hadron duality, we obtain |V_cb| = 0.0404 +- 0.0013.Comment: 11 pages postscript, also available through http://w4.lns.cornell.edu/public/CLNS, submitted to PR

    Observation of the Ωc0\Omega_{c}^{0} Charmed Baryon at CLEO

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    The CLEO experiment at the CESR collider has used 13.7 fb−1^{-1} of data to search for the production of the Ωc0\Omega_c^0 (css-ground state) in e+e−e^{+}e^{-} collisions at s≃10.6\sqrt{s} \simeq 10.6 {\rm GeV}. The modes used to study the Ωc0\Omega_c^0 are Ω−π+\Omega^- \pi^+, Ω−π+π0\Omega^- \pi^+ \pi^0, Ξ−K−pi+π+\Xi^- K^- pi^+ \pi^+, Ξ0K−pi+\Xi^0 K^- pi^+, and Ω−π+π−π+\Omega^- \pi^+ \pi^- \pi^+. We observe a signal of 40.4±\pm9.0(stat) events at a mass of 2694.6±\pm2.6(stat)±\pm1.9(syst) {\rm MeV/c2c^2}, for all modes combined.Comment: 10 pages postscript, also available through http://w4.lns.cornell.edu/public/CLN

    Observation of B→ϕKB\to \phi K and B→ϕK∗B\to \phi K^{*}

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    We have studied two-body charmless hadronic decays of BB mesons into the final states phi K and phi K^*. Using 9.7 million BBˉB\bar{B} pairs collected with the CLEO II detector, we observe the decays B- -> phi K- and B0 -> phi K*0 with the following branching fractions: BR(B- -> phi K-)=(5.5 +2.1-1.8 +- 0.6) x 10^{-6} and BR(B0 -> phi K*0)=(11.5 +4.5-3.7 +1.8-1.7) x 10^{-6}. We also see evidence for the decays B0 -> phi K0 and B- -> phi K*-. However, since the statistical significance is not overwhelming for these modes we determine upper limits of <12.3 x 10^{-6} and <22.5 x 10^{-6} (90% C.L.) respectively.Comment: 9 pages postscript, also available through http://w4.lns.cornell.edu/public/CLN

    Evidence of New States Decaying into Ξc′π\Xi^{\prime}_{c}\pi

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    Using 13.7 fb−1fb^{-1} of data recorded by the CLEO detector at CESR, we report evidence for two new charmed baryons: one decaying into Ξc0′π+\Xi_c^{0 \prime}\pi^+ with the subsequent decay Ξc0′→Ξc0γ\Xi_c^{0 \prime} \to \Xi_c^0 \gamma, and its isospin partner decaying into Ξc+′π−\Xi_c^{+ \prime} \pi^- followed by Ξc+′→Ξc+γ\Xi_c^{+\prime} \to \Xi_c^+\gamma. We measure the following mass differences for the two states: M(Ξc0γπ+)−M(Ξc0)M(\Xi_c^0 \gamma \pi^+)-M(\Xi_c^0)=318.2+-1.3+-2.9 MeV, and M(Ξc+γπ−)−M(Ξc+)M(\Xi_c^+ \gamma \pi^-)-M(\Xi_c^+)=324.0+-1.3+-3.0 MeV. We interpret these new states as the JP=1/2−Ξc1J^P = 1/2^- \Xi_{c1} particles, the charmed-strange analogs of the Λc1+(2593)\Lambda_{c1}^+(2593).Comment: 10 pages postscript, also available through http://w4.lns.cornell.edu/public/CLN

    First Observation of B -> D(*) rho', rho' -> omega pi-

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    We report on the observation of B-> D(*) pi+ pi- pi- pi^o decays. The branching ratios for D*+ and D*o are (1.72+/-0.14+/-0.24)% and (1.80+/-0.24+/-0.27)%, respectively. Each final state has a D* omega pi- component, with branching ratios (0.29+/-0.03+/-0.04)% and (0.45+/-0.10+/-0.07)% for the D*+ and D*o modes, respectively. We also observe B -> D omega pi- decays. The branching ratios for D+ and Do are (0.28+/-0.05+/-0.04)% and (0.41+/-0.07+/-0.06)%, respectively. A spin parity analysis of the D omega pi- final state prefers a wide 1^- resonance. A fit to the omega pi- mass spectrum finds a central mass of (1349+/-25^{+10}_{-5}) MeV and width of (547+/-86^{+46}_{-45}) MeV. We identify this object as the rho(1450) or the \rho'.Comment: 42 pages postscript, also available through http://w4.lns.cornell.edu/public/CLNS, To Appear in PR

    Search for the Decay Υ(1S)→γη′\Upsilon(1S)\to \gamma\eta^{'}

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    We report on a search for the radiative decay U(1S) -> gamma + eta' in 61.3 pb^-1 of data taken with the CLEO II detector at the Cornell Electron Storage Ring. Three decay chains were investigated, all involving eta' -> pi+ pi- + eta, followed by eta -> gamma + gamma, eta -> pi0 + pi0 + pi0, or eta -> pi+ + pi- + pi0. We find no candidate events in any of the three cases and set a combined upper limit of 1.6 x 10^-5 at 90% C.L., significantly smaller than the previous limit. We compare our result to other radiative U(1S) decays, to radiative J/psi decays, and to theoretical predictions.Comment: 9 pages postscript, also available through http://w4.lns.cornell.edu/public/CLNS, submitted to PR

    First observations of separated atmospheric nu_mu and bar{nu-mu} events in the MINOS detector

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    The complete 5.4 kton MINOS far detector has been taking data since the beginning of August 2003 at a depth of 2070 meters water-equivalent in the Soudan mine, Minnesota. This paper presents the first MINOS observations of nuµ and [overline nu ]µ charged-current atmospheric neutrino interactions based on an exposure of 418 days. The ratio of upward- to downward-going events in the data is compared to the Monte Carlo expectation in the absence of neutrino oscillations, giving Rup/downdata/Rup/downMC=0.62-0.14+0.19(stat.)±0.02(sys.). An extended maximum likelihood analysis of the observed L/E distributions excludes the null hypothesis of no neutrino oscillations at the 98% confidence level. Using the curvature of the observed muons in the 1.3 T MINOS magnetic field nuµ and [overline nu ]µ interactions are separated. The ratio of [overline nu ]µ to nuµ events in the data is compared to the Monte Carlo expectation assuming neutrinos and antineutrinos oscillate in the same manner, giving R[overline nu ][sub mu]/nu[sub mu]data/R[overline nu ][sub mu]/nu[sub mu]MC=0.96-0.27+0.38(stat.)±0.15(sys.), where the errors are the statistical and systematic uncertainties. Although the statistics are limited, this is the first direct observation of atmospheric neutrino interactions separately for nuµ and [overline nu ]µ

    Cardiac telocytes — their junctions and functional implications

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    Telocytes (TCs) form a cardiac network of interstitial cells. Our previous studies have shown that TCs are involved in heterocellular contacts with cardiomyocytes and cardiac stem/progenitor cells. In addition, TCs frequently establish ‘stromal synapses’ with several types of immunoreactive cells in various organs (www.telocytes.com). Using electron microscopy (EM) and electron microscope tomography (ET), we further investigated the interstitial cell network of TCs and found that TCs form ‘atypical’ junctions with virtually all types of cells in the human heart. EM and ET showed different junction types connecting TCs in a network (puncta adhaerentia minima, processus adhaerentes and manubria adhaerentia). The connections between TCs and cardiomyocytes are ‘dot’ junctions with nanocontacts or asymmetric junctions. Junctions between stem cells and TCs are either ‘stromal synapses’ or adhaerens junctions. An unexpected finding was that TCs have direct cell–cell (nano)contacts with Schwann cells, endothelial cells and pericytes. Therefore, ultrastructural analysis proved that the cardiac TC network could integrate the overall ‘information’ from vascular system (endothelial cells and pericytes), nervous system (Schwann cells), immune system (macrophages, mast cells), interstitium (fibroblasts, extracellular matrix), stem cells/progenitors and working cardiomyocytes. Generally, heterocellular contacts occur by means of minute junctions (point contacts, nanocontacts and planar contacts) and the mean intermembrane distance is within the macromolecular interaction range (10–30 nm). In conclusion, TCs make a network in the myocardial interstitium, which is involved in the long-distance intercellular signaling coordination. This integrated interstitial system appears to be composed of large homotropic zones (TC–TC junctions) and limited (distinct) heterotropic zones (heterocellular junctions of TCs)
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