39 research outputs found

    Mass Splitting and Production of ÎŁc0\Sigma_c^0 and ÎŁc++\Sigma_c^{++} Measured in 500GeV500 {GeV} π−−\pi^- -N Interactions

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    From a sample of 2722±782722 \pm 78 Λc+\Lambda_c^+ decaying to the pK−π+pK^-\pi^+ final state, we have observed, in the hadroproduction experiment E791 at Fermilab, 143±20143 \pm 20 ÎŁc0\Sigma_c^0 and 122±18122 \pm 18 ÎŁc++\Sigma_c^{++} through their decays to Λc+π±\Lambda_c^+ \pi^{\pm}. The mass difference M(ÎŁc0)−M(Λc+M(\Sigma_c^0) - M(\Lambda_c^+) is measured to be (167.38±0.29±0.15)MeV(167.38\pm 0.29\pm 0.15) {MeV}; for M(ÎŁc++)−M(Λc+)M(\Sigma_c^{++}) - M(\Lambda_c^+), we find (167.76±0.29±0.15)MeV(167.76\pm 0.29\pm0.15) {MeV}. The rate of Λc+\Lambda_c^+ production from decays of the ÎŁc\Sigma_c triplet is (22\pm 2\pm 3) {%} of the total Λc+\Lambda_c^+ production assuming equal rate of production from all three, as measured for ÎŁc0\Sigma_c^0 and ÎŁc++\Sigma_c^{++}. We do not observe a statistically significant ÎŁc\Sigma_c baryon-antibaryon production asymmetry. The xFx_F and pt2p_t^2 spectra of Λc+\Lambda_c^+ from ÎŁc\Sigma_c decays are observed to be similar to those for all Λc+\Lambda_c^+'s produced.Comment: 15 pages, uuencoded postscript 3 figures uuencoded, tar-compressed fil

    Heavy quarkonium: progress, puzzles, and opportunities

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    A golden age for heavy quarkonium physics dawned a decade ago, initiated by the confluence of exciting advances in quantum chromodynamics (QCD) and an explosion of related experimental activity. The early years of this period were chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in 2004, which presented a comprehensive review of the status of the field at that time and provided specific recommendations for further progress. However, the broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles could only be partially anticipated. Since the release of the YR, the BESII program concluded only to give birth to BESIII; the BB-factories and CLEO-c flourished; quarkonium production and polarization measurements at HERA and the Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the deconfinement regime. All these experiments leave legacies of quality, precision, and unsolved mysteries for quarkonium physics, and therefore beg for continuing investigations. The plethora of newly-found quarkonium-like states unleashed a flood of theoretical investigations into new forms of matter such as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the spectroscopy, decays, production, and in-medium behavior of c\bar{c}, b\bar{b}, and b\bar{c} bound states have been shown to validate some theoretical approaches to QCD and highlight lack of quantitative success for others. The intriguing details of quarkonium suppression in heavy-ion collisions that have emerged from RHIC have elevated the importance of separating hot- and cold-nuclear-matter effects in quark-gluon plasma studies. This review systematically addresses all these matters and concludes by prioritizing directions for ongoing and future efforts.Comment: 182 pages, 112 figures. Editors: N. Brambilla, S. Eidelman, B. K. Heltsley, R. Vogt. Section Coordinators: G. T. Bodwin, E. Eichten, A. D. Frawley, A. B. Meyer, R. E. Mitchell, V. Papadimitriou, P. Petreczky, A. A. Petrov, P. Robbe, A. Vair

    Oncogenic Signaling Pathways in The Cancer Genome Atlas

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    Genetic alterations in signaling pathways that control cell-cycle progression, apoptosis, and cell growth are common hallmarks of cancer, but the extent, mechanisms, and co-occurrence of alterations in these pathways differ between individual tumors and tumor types. Using mutations, copy-number changes, mRNA expression, gene fusions and DNA methylation in 9,125 tumors profiled by The Cancer Genome Atlas (TCGA), we analyzed the mechanisms and patterns of somatic alterations in ten canonical pathways: cell cycle, Hippo, Myc, Notch, Nrf2, PI-3-Kinase/Akt, RTK-RAS, TGFb signaling, p53 and beta-catenin/Wnt. We charted the detailed landscape of pathway alterations in 33 cancer types, stratified into 64 subtypes, and identified patterns of co-occurrence and mutual exclusivity. Eighty-nine percent of tumors had at least one driver alteration in these one alteration potentially targetable by currently available drugs. Thirty percent of tumors had multiple targetable alterations, indicating opportunities for combination therapy

    Analysis and Design of Watermarking Algorithms for Improved Resistance to Compression

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    Analysis and Design of Secure Watermark-Based Authentication Systems

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    Fault Diagnosis in Discrete-Event Systems: Framework and Model Reduction

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    A state-based approach for on-line passive fault diagnosis in systems modelled as finite-state automata is presented. In this framework, the system and the diagnoser (the fault detection system) do not have to be initialized at the same time. Furthermore, no information about the state or even the condition (failure status) of the system before the initiation of diagnosis is required. The design of the fault detection system, in the worst case, has exponential time complexity. A model reduction scheme with polynomial time complexity is introduced to reduce the computational complexity of the design. 1 Introduction Fault detection systems are of paramount importance in aerospace, manufacturing and process industries. This is due to the crucial role they play in protecting life and property, and in increasing operational time and productivity. Solving diagnostic problems for complex systems is a complicated task requiring a reliable, systematic approach. As a result, fault diagnosis has..

    Supremum Operators and Computation of Supremal Elements in System Theory

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    . Constrained supremum and supremum operators are introduced to obtain a general procedure for computing supremal elements of upper semilattices. Examples of such elements include supremal (A; B)-invariant subspaces in linear system theory and supremal controllable sublanguages in discrete-event system theory. For some examples, we show that the algorithms available in the literature are special cases of our procedure. Our iterative algorithms may also provide more insight into applications; in the case of supremal controllable subpredicate, the algorithm enables us to derive a lookahead policy for supervisory control of discrete-event systems. Keywords. Discrete-event systems, linear systems, lattice theory, supervisory control, partition, supremal elements, supremum operators AMS subject classifications. 93B, 68Q20 1 Introduction In system theory, we sometimes encounter lattice structures [2], [5]. Examples are the lattice of equivalence relations in the theory of sequential machi..
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