22 research outputs found

    A Flexible and Secure Deployment Framework for Distributed Applications

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    This paper describes an implemented system which is designed to support the deployment of applications offering distributed services, comprising a number of distributed components. This is achieved by creating high level placement and topology descriptions which drive tools that deploy applications consisting of components running on multiple hosts. The system addresses issues of heterogeneity by providing abstractions over host-specific attributes yielding a homogeneous run-time environment into which components may be deployed. The run-time environments provide secure binding mechanisms that permit deployed components to bind to stored data and services on the hosts on which they are running.Comment: 2nd International Working Conference on Component Deployment (CD 2004), Edinburgh, Scotlan

    An information flow architecture for Global Smart Spaces

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    In this paper we describe an architecture which: Permits the deployment and execution of components in appropriate geographical locations. Provides security mechanisms that prevent misuse of the architecture. Supports a programming model that is familiar to application programmers. Permits installed components to share data. Permits the deployed components to communicate via communication channels. Provides evolution mechanisms permitting the dynamic rearrangement of inter-connection topologies the components that they connect. Supports the specification and deployment of distributed component deployments.Preprin

    An information flow architecture for Global Smart Spaces

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    In this paper we describe an architecture which: Permits the deployment and execution of components in appropriate geographical locations. Provides security mechanisms that prevent misuse of the architecture. Supports a programming model that is familiar to application programmers. Permits installed components to share data. Permits the deployed components to communicate via communication channels. Provides evolution mechanisms permitting the dynamic rearrangement of inter-connection topologies the components that they connect. Supports the specification and deployment of distributed component deployments

    Spanish Shorter-than-Short Fiction: Subverting Tradition

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    Enhanced deuteron coalescence probability in jets

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    The transverse-momentum (pT) spectra and coalescence parameters B2 of (anti)deuterons are measured in pp collisions at s√=13 TeV for the first time in and out of jets. In this measurement, the direction of the leading particle with the highest pT in the event (pleadT>5 GeV/c) is used as an approximation for the jet axis. The event is consequently divided into three azimuthal regions and the jet signal is obtained as the difference between the Toward region, that contains jet fragmentation products in addition to the underlying event (UE), and the Transverse region, which is dominated by the UE. The coalescence parameter in the jet is found to be approximately a factor of 10 larger than that in the underlying event. This experimental observation is consistent with the coalescence picture and can be attributed to the smaller average phase-space distance between nucleons inside the jet cone as compared to the underlying event. The results presented in this Letter are compared to predictions from a simple nucleon coalescence model, where the phase space distributions of nucleons are generated using PYTHIA 8 with the Monash 2013 tuning, and to predictions from a deuteron production model based on ordinary nuclear reactions with parametrized energy-dependent cross sections tuned on data. The latter model is implemented in PYTHIA 8.3. Both models reproduce the observed large difference between in-jet and out-of-jet coalescence parameters, although the almost flat trend of the BJet2 is not reproduced by the models, which instead give a decreasing trend

    Neutron emission in ultraperipheral Pb-Pb collisions at sNN\sqrt {s_{NN}} = 5.02 TeV

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    In ultraperipheral collisions (UPCs) of relativistic nuclei without overlap of nuclear densities, the two nuclei are excited by the Lorentz-contracted Coulomb fields of their collision partners. In these UPCs, the typical nuclear excitation energy is below a few tens of MeV, and a small number of nucleons are emitted in electromagnetic dissociation (EMD) of primary nuclei, in contrast to complete nuclear fragmentation in hadronic interactions. The cross sections of emission of given numbers of neutrons in UPCs of 208^{208}Pb nuclei at sNN=5.02\sqrt{s_{\mathrm{NN}}}=5.02~TeV were measured with the neutron zero degree calorimeters (ZDCs) of the ALICE detector at the LHC, exploiting a similar technique to that used in previous studies performed at sNN=2.76\sqrt{s_{\mathrm{NN}}}=2.76~TeV. In addition, the cross sections for the exclusive emission of 1, 2, 3, 4 and 5 forward neutrons in the EMD, not accompanied by the emission of forward protons, and thus mostly corresponding to the production of 207,206,205,204,203^{207,206,205,204,203}Pb, respectively, were measured for the first time. The predictions from the available models describe the measured cross sections well. These cross sections can be used for evaluating the impact of secondary nuclei on the LHC components, in particular, on superconducting magnets, and also provide useful input for the design of the Future Circular Collider (FCC-hh).In ultraperipheral collisions (UPCs) of relativistic nuclei without overlap of nuclear densities, the two nuclei are excited by the Lorentz-contracted Coulomb fields of their collision partners. In these UPCs, the typical nuclear excitation energy is below a few tens of MeV, and a small number of nucleons are emitted in electromagnetic dissociation (EMD) of primary nuclei, in contrast to complete nuclear fragmentation in hadronic interactions. The cross sections of emission of given numbers of neutrons in UPCs of Pb208 nuclei at sNN=5.02 TeV were measured with the neutron zero degree calorimeters (ZDCs) of the ALICE detector at the LHC, exploiting a similar technique to that used in previous studies performed at sNN=2.76 TeV. In addition, the cross sections for the exclusive emission of one, two, three, four, and five forward neutrons in the EMD, not accompanied by the emission of forward protons, and thus mostly corresponding to the production of Pb207,206,205,204,203, respectively, were measured for the first time. The predictions from the available models describe the measured cross sections well. These cross sections can be used for evaluating the impact of secondary nuclei on the LHC components, in particular, on superconducting magnets, and also provide useful input for the design of the Future Circular Collider (FCC-hh).In ultraperipheral collisions (UPCs) of relativistic nuclei without overlap of nuclear densities, the two nuclei are excited by the Lorentz-contracted Coulomb fields of their collision partners. In these UPCs, the typical nuclear excitation energy is below a few tens of MeV, and a small number of nucleons are emitted in electromagnetic dissociation (EMD) of primary nuclei, in contrast to complete nuclear fragmentation in hadronic interactions. The cross sections of emission of given numbers of neutrons in UPCs of 208^{208}Pb nuclei at sNN=5.02\sqrt{s_{\mathrm{NN}}}=5.02 TeV were measured with the neutron zero degree calorimeters (ZDCs) of the ALICE detector at the LHC, exploiting a similar technique to that used in previous studies performed at sNN=2.76\sqrt{s_{\mathrm{NN}}}=2.76 TeV. In addition, the cross sections for the exclusive emission of one, two, three, four, and five forward neutrons in the EMD, not accompanied by the emission of forward protons, and thus mostly corresponding to the production of 207,206,205,204,203^{207,206,205,204,203}Pb, respectively, were measured for the first time. The predictions from the available models describe the measured cross sections well. These cross sections can be used for evaluating the impact of secondary nuclei on the LHC components, in particular, on superconducting magnets, and also provide useful input for the design of the Future Circular Collider (FCC-hh)

    First measurement of Λc+\Lambda_\mathrm{c}^{+} production down to pT=0p_\mathrm{T} = 0 in pp and p-Pb collisions at sNN=5.02\sqrt{s_\mathrm{NN}} = 5.02 TeV

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    The production of prompt Λc+{\mathrm {\Lambda_{c}^{+}}} baryons has been measured at midrapidity in the transverse momentum interval 0 Λc+ baryons has been measured at midrapidity in the transverse momentum interval 0<pT<1 GeV/c for the first time, in pp and p–Pb collisions at a center-of-mass energy per nucleon-nucleon collision sNN=5.02TeV. The measurement was performed in the decay channel Λc+→pKS0 by applying new decay reconstruction techniques using a Kalman-Filter vertexing algorithm and adopting a machine-learning approach for the candidate selection. The pT-integrated Λc+ production cross sections in both collision systems were determined and used along with the measured yields in Pb–Pb collisions to compute the pT-integrated nuclear modification factors RpPb and RAA of Λc+ baryons, which are compared to model calculations that consider nuclear modification of the parton distribution functions. The Λc+/D0 baryon-to-meson yield ratio is reported for pp and p–Pb collisions. Comparisons with models that include modified hadronization processes are presented, and the implications of the results on the understanding of charm hadronization in hadronic collisions are discussed. A significant (3.7σ) modification of the mean transverse momentum of Λc+ baryons is seen in p–Pb collisions with respect to pp collisions, while the pT-integrated Λc+/D0 yield ratio was found to be consistent between the two collision systems within the uncertainties.The production of prompt \mathrm {\Lambda_{c}^{+}}baryonshasbeenmeasuredatmidrapidityinthetransversemomentuminterval baryons has been measured at midrapidity in the transverse momentum interval 0<p_{\rm T}<1GeV/ GeV/cforthefirsttime,inppandpPbcollisionsatacentreofmassenergypernucleonnucleoncollision for the first time, in pp and p-Pb collisions at a centre-of-mass energy per nucleon-nucleon collision \sqrt{s_\mathrm{NN}} = 5.02TeV.Themeasurementwasperformedinthedecaychannel TeV. The measurement was performed in the decay channel {\rm \Lambda_{c}^{+}\to p K^{0}_{S}}byapplyingnewdecayreconstructiontechniquesusingaKalmanFiltervertexingalgorithmandadoptingamachinelearningapproachforthecandidateselection.The by applying new decay reconstruction techniques using a Kalman-Filter vertexing algorithm and adopting a machine-learning approach for the candidate selection. The p_{\rm T}integrated-integrated \mathrm {\Lambda_{c}^{+}}productioncrosssectionsinbothcollisionsystemsweredeterminedandusedalongwiththemeasuredyieldsinPbPbcollisionstocomputethe production cross sections in both collision systems were determined and used along with the measured yields in Pb-Pb collisions to compute the p_{\rm T}integratednuclearmodificationfactors-integrated nuclear modification factors R_{\rm pPb}and and R_\mathrm{AA}of of \mathrm{\Lambda_{c}^{+}}baryons,whicharecomparedtomodelcalculationsthatconsidernuclearmodificationofthepartondistributionfunctions.The baryons, which are compared to model calculations that consider nuclear modification of the parton distribution functions. The \mathrm{\Lambda_{c}^{+}/D^0}baryontomesonyieldratioisreportedforppandpPbcollisions.Comparisonswithmodelsthatincludemodifiedhadronisationprocessesarepresented,andtheimplicationsoftheresultsontheunderstandingofcharmhadronisationinhadroniccollisionsarediscussed.Asignificant( baryon-to-meson yield ratio is reported for pp and p-Pb collisions. Comparisons with models that include modified hadronisation processes are presented, and the implications of the results on the understanding of charm hadronisation in hadronic collisions are discussed. A significant (3.7\sigma)modificationofthemeantransversemomentumof) modification of the mean transverse momentum of \mathrm {\Lambda_{c}^{+}}baryonsisseeninpPbcollisionswithrespecttoppcollisions,whilethe baryons is seen in p-Pb collisions with respect to pp collisions, while the p_{\rm T}integrated-integrated \mathrm{\Lambda_{c}^{+}/D^0}$ yield ratio was found to be consistent between the two collision systems within the uncertainties

    Measurement of the lifetime and Λ\Lambda separation energy of Λ3H^{3}_{\Lambda}\mathrm H

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    The most precise measurements to date of the Λ3H^{3}_{\Lambda}\mathrm H lifetime τ\tau and Λ\Lambda separation energy BΛ{\rm B}_{\Lambda} are obtained using the data sample of Pb-Pb collisions at sNN=\sqrt{s_{\mathrm{NN}}}= 5.02 TeV collected by ALICE at the LHC. The Λ3H^{3}_{\Lambda}\mathrm H is reconstructed via its charged two-body mesonic decay channel (Λ3H^{3}_{\Lambda}\mathrm{H} \rightarrow 3^3He + π\pi^- and the charge-conjugate process). The measured values τ=[253±11 (stat.)±6 (syst.)]\tau = [253 \pm 11 \text{ (stat.)} \pm 6 \text{ (syst.)}] ps and BΛ=[72±63 (stat.)±36 (syst.)]{\rm B}_{\Lambda}= [72 \pm 63 \text{ (stat.)} \pm 36 \text{ (syst.)}] keV are compatible with predictions from effective field theories and conclusively confirm that the Λ3H^{3}_{\Lambda}\mathrm H is a weakly-bound system.The most precise measurements to date of the HΛ3 lifetime τ and Λ separation energy BΛ are obtained using the data sample of Pb-Pb collisions at sNN=5.02  TeV collected by ALICE at the LHC. The HΛ3 is reconstructed via its charged two-body mesonic decay channel (HΛ3→He3+π- and the charge-conjugate process). The measured values τ=[253±11(stat)±6(syst)]  ps and BΛ=[102±63(stat)±67(syst)]  keV are compatible with predictions from effective field theories and confirm that the HΛ3 structure is consistent with a weakly bound system.The most precise measurements to date of the Λ3H^{3}_{\Lambda}\mathrm H lifetime τ\tau and Λ\Lambda separation energy BΛ{\rm B}_{\Lambda} are obtained using the data sample of Pb-Pb collisions at sNN=\sqrt{s_{\mathrm{NN}}}= 5.02 TeV collected by ALICE at the LHC. The Λ3H^{3}_{\Lambda}\mathrm H is reconstructed via its charged two-body mesonic decay channel (Λ3H^{3}_{\Lambda}\mathrm{H} \rightarrow3^3He + π\pi^- and the charge-conjugate process). The measured values τ=[253±11 (stat.)±6 (syst.)]\tau = [253 \pm 11 \text{ (stat.)} \pm 6 \text{ (syst.)}] ps and BΛ=[102±63 (stat.)±67 (syst.)]{\rm B}_{\Lambda}= [102 \pm 63 \text{ (stat.)} \pm 67 \text{ (syst.)}] keV are compatible with predictions from effective field theories and confirm that the Λ3H^{3}_{\Lambda}\mathrm H structure is consistent with a weakly-bound system
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