18,491 research outputs found

    Exotic hadron spectroscopy at the LHCb experiment

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    The LHCb experiment is designed to study the decays and properties of heavy flavoured hadrons produced in the forward region from proton-proton collisions at the CERN Large Hadron Collider. During Run 1, it has recorded the world's largest data sample of beauty and charm hadrons, enabling precise studies into the spectroscopy of such particles, including discoveries of new states and measurements of their masses, widths and quantum numbers. An overview of recent LHCb results in the area of exotic hadron spectroscopy is presented, focussing on the discovery of the first pentaquark states in the Λb0→J/ψpK−\Lambda_b^0 \to J/\psi p K^- channel and a search for them in the related Λb0→J/ψpπ−\Lambda_b^0 \to J/\psi p\pi^- mode. The LHCb non-confirmation of the D0 tetraquark candidate in the Bs0π+B_s^0\pi^+ invariant mass spectrum is presented.Comment: 4 pages, 8 figures, proceedings for Rencontres de Blois 201

    Multiplicities in ultrarelativistic proton-(anti)proton collisions and negative binomial distribution fits

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    Likelihood ratio tests are performed for the hypothesis that charged-particle multiplicities measured in proton-(anti)proton collisions at s\sqrt{s} = 0.9 and 2.36 TeV are distributed according to the negative binomial form. Results indicate that the hypothesis should be rejected in the all cases of ALICE-LHC measurements in the limited pseudo-rapidity windows, whereas should be accepted in the corresponding cases of UA5 data. Possible explanations of that and of the disagreement with the least-squares fitting method are given.Comment: 14 pages, clarified version, reference added. To appear in International Journal of Modern Physics

    Success Strategies Being Implemented in Fresh Milk Supply Chains

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    Deregulation of the Australian dairy industry, and ensuing supermarket strategies are transforming the fresh milk supply chains. Factors such as increasing consumer awareness, concerns about food safety and environment, innovation, supply chain integration and rationalisation of supply base are adding momentum to this transformation. Milk processors in response to changing market expectations are getting proactive in their relationship with retailers across all aspects of business, innovating to generate sufficient returns from proprietary brands and strategically orienting themselves to develop a mixed customer portfolio and appropriate management structures to service that portfolio. Milk producers are expanding businesses to achieve production and cost efficiencies and strengthening contractual relationships on input and output side for a greater security.Livestock Production/Industries,

    Discovery potential for the Standard Model Higgs at ATLAS

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    The potential of the ATLAS experiment to discover or exclude the Standard Model Higgs boson is reviewed. Several important decay channels are considered, and more will be included in the future. The statistical treatment used here to combine the channels relies on a large sample approximation that is expected to be valid for an integrated luminosity of at least 2 fb−1. Results are presented for the expected statistical significance of discovery and expected exclusion limits

    Topics in statistical data analysis for high-energy physics

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    These lectures concern two topics that are becoming increasingly important in the analysis of High Energy Physics (HEP) data: Bayesian statistics and multivariate methods. In the Bayesian approach we extend the interpretation of probability to cover not only the frequency of repeatable outcomes but also to include a degree of belief. In this way we are able to associate probability with a hypothesis and thus to answer directly questions that cannot be addressed easily with traditional frequentist methods. In multivariate analysis we try to exploit as much information as possible from the characteristics that we measure for each event to distinguish between event types. In particular we will look at a method that has gained popularity in HEP in recent years: the boosted decision tree (BDT).Comment: 22 pages, Lectures given at the 2009 European School of High-Energy Physics, Bautzen, Germany, 14-27 Jun 200

    Collective Bargaining in the Public Sector : Prince Edward Island

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    Les gens sont de plus en plus opposĂ©s aux grĂšves qui, dans le secteur public, semblent toucher davantage la population que les participants eux-mĂȘmes. Ainsi, les comparaisons entre les taux de salaire qui sont payĂ©s dans les secteurs public et privĂ© suscitent de plus en plus de critiques Ă  mesure que les niveaux de traitement des employĂ©s du secteur public atteignent et dĂ©passent ceux du secteur privĂ©. L'un et l'autre doivent relever le dĂ©fi en trouvant la solution opportune.La faiblesse du rĂ©gime de nĂ©gociation collective dans le secteur public, qu'il s'agisse du gouvernement fĂ©dĂ©ral, des provinces ou des municipalitĂ©s, rĂ©side dans l'impuissance Ă  reconnaĂźtre que le secteur public diffĂšre du secteur privĂ©. Le ConseilĂ©conomique du Canada a constatĂ© que tant les nĂ©gociateurs des organismes publics eux-mĂȘmes que ceux de leurs employĂ©s sont soumis au mĂȘme type de contraintes que celles que la concurrence des marchĂ©s fait peser sur les nĂ©gociations collectives dans le recteur privĂ©. Les gouvernements dĂ©tiennent un pouvoir de taxer illimitĂ© et les syndicats des employĂ©s des services publics sont en mesure, du moins dans les secteurs-clĂ©s, de disloquer la vie Ă©conomique, ce qui leur permet potentiellement d'obtenir de avantages inĂ©quitables sur le secteur privĂ© qui forme plus de quatre-vingts pour cent de la main-d'oeuvre et qui fournit la grande partie des impĂŽts sur les revenus qui alimentent les bordereaux de paie de l'État.La nouvelle rĂ©glementation du gouvernement de l'Ăźle du Prince-Édouard en matiĂšre de nĂ©gociations collectives pour ce qui concerne les enseignants et les fonctionnaires s'inspire de critĂšres suggĂ©rĂ©s par le Conseil Ă©conomique et qui existent depuis longtemps dans la fonction publique en Grande-Bretagne, en Nouvelle-ZĂ©lande ainsi que dans le Tennessee Valley Act, etc. Les nĂ©gociateurs et les arbitres doivent Ă©tablir les taux de salaire des employĂ©s du secteur public de façon Ă  les ajuster aux taux qui sont payĂ©s par les « bons » employeurs du secteur privĂ©. L'Ăźle du Prince-Edouard dĂ©finit le « bon employeur » en parlant « des employeurs qui paient les meilleurs salaires » dans l'Ăźle. Si l'on tient compte des taux de salaire payĂ©s par les autres gouvernements des Maritimes, on tiendra Ă©galement compte des diffĂ©rences Ă©conomiques entre les provinces, tel le revenu disponible, par exemple, ainsi que d'autres facteurs comme la nĂ©cessitĂ© d'avoir un personnel compĂ©tent.De pareils critĂšres modifient le concept de la force qui existe dans le secteur privĂ© en limitant beaucoup les divergences possibles dans les nĂ©gociations. Ainsi, la cueillette en commun et l'Ă©change des donnĂ©es entre les parties devient chose possible. Le recours Ă  ces critĂšres rend plus praticable l'acceptation du mĂ©canisme de l'arbitrage dans les diffĂ©rends, puisque l'arbitre est, lui aussi, obligĂ© de s'en tenir Ă  ces critĂšres. La grĂšve devient ainsi un moyen inopportun et inutile de rĂ©soudre les diffĂ©rends dans les services publics lorsqu'il existe de meilleures façons de les rĂ©soudre.Le rĂ©gime apparaĂźtra ainsi Ă©quitable tant aux employĂ©s des services publics qu'aux contribuables, ce qui est important pour les hommes politiques, car le gouvernement peut ainsi avoir sa part de travailleurs compĂ©tents et ceux-ci ĂȘtre en mesure de voir Ă©voluer leurs traitements selon les changements qui se produisent dans le secteur privĂ©.Le rĂ©gime de nĂ©gociation du gouvernement fĂ©dĂ©ral a cessĂ© de s'inspirer du type de nĂ©gociation britannique en 1966 en optant pour le concept de la force et en nĂ©gligeant de dĂ©finir ce qu'il entendait par le « bon » employeur du secteur privĂ©.L'Ăźle du Prince-Edouard a aussi copiĂ© le fort efficace systĂšme de consultation instituĂ©e en Grande-Bretagne en vue de rĂ©soudre les questions relatives aux conditions de travail par l'Ă©tablissement de conseils consultatifs mixtes tant au niveau du gouvernement lui-mĂȘme que des diffĂ©rents ministĂšres.Un rĂ©gime d'arbitrage fondĂ© sur des « comparaisons Ă©quitables » peut aussi s'appliquer dans les entreprises d'intĂ©rĂȘt public, comme les chemins de fer, par exemple, et dans les municipalitĂ©s ainsi que partout oĂč les entreprises subviennent Ă  leurs besoins Ă  mĂȘme les impĂŽts des contribuables.The author reports on Prince Edward Island's attempt to solve some of the key issues of public sector bargaining through Us recent collective bargaining regulations for teachers and the public service

    Charged particle multiplicity and momenta in e+e−→We^{+}e^{-} \to W-pair decays at 189 GeV

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    The charged particle multiplicity of W-pair decays is measured with the ALEPH detector at LEP at a cms energy of 189GeV. This is motivated by the study of possible colour reconnection effects in W-pairs where both decay hadronically. The average charged multiplicity of WW>qqqq is compared with predictions of fragmentation models tuned to measurements performed at the Z peak and with measured multiplicities in WW>qqlv events. It is compatible, both with models without implementation of colour reconnection, and with the models including colour reconnection that are studied here

    A FAMILY OF CATION ATPASE-LIKE MOLECULES FROM PLASMODIUM-FALCIPARUM

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    Abstract. We report the nucleotide and derived amino acid sequence of the ATPase 1 gene from Plasmodium falciparum. The amino acid sequence shares homology with the family of "P-type cation transloeating ATPases in conserved regions important for nucleotide binding, conformational change, or phosphorylation. The gene, which is present on chromosome 5, has a product longer than any other reported for a P-type ATPase. Interstrain analysis from 12 parasite isolates by the polymerase chain reaction reveals that a 330-bp nucleotide sequence encoding three cytoplasmic regions conserved in cation ATPases (regions a-c) is of constant length. By contrast, another 360-bp sequence which is one of four regions we refer to as

    Highlights from LHCb

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    The recent highlights from LHCb in soft QCD and Heavy Ion physics are presented. This includes measurements from collisions of proton and lead [see formula in PDF] ion beams with other beams as well as noble gas targets. An outlook on future analyses of [see formula in PDF] collisions is presented

    Deviation from one-dimensionality in stationary properties and collisional dynamics of matter-wave solitons

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    By means of analytical and numerical methods, we study how the residual three-dimensionality affects dynamics of solitons in an attractive Bose-Einstein condensate loaded into a cigar-shaped trap. Based on an effective 1D Gross-Pitaevskii equation that includes an additional quintic self-focusing term, generated by the tight transverse confinement, we find a family of exact one-soliton solutions and demonstrate stability of the entire family, despite the possibility of collapse in the 1D equation with the quintic self-focusing nonlinearity. Simulating collisions between two solitons in the same setting, we find a critical velocity, VcV_{c}, below which merger of identical in-phase solitons is observed. Dependence of VcV_{c} on the strength of the transverse confinement and number of atoms in the solitons is predicted by means of the perturbation theory and investigated in direct simulations. Symmetry breaking in collisions of identical solitons with a nonzero phase difference is also shown in simulations and qualitatively explained by means of an analytical approximation.Comment: 10 pages, 7 figure
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