1,788 research outputs found

    Dynamic virtualization of AliEn grid jobs using the Vmbatch system

    Get PDF
    The Vmbatch system is shown to be a robust and reliable system for running batch jobs inside virtual machines. The system has been developed as a lightweight tool to establish and clean up virtual machines for CernVM processing of ALICE grid jobs. It can work with a stock guest image and interfaces with the Torque batch system. With the use of virtualization, the system can create a homogeneous execution environment for grid jobs that can be expanded dynamically upon availability of generic computing resources

    The ALICE Grid Workflow for LHC Run 3

    Get PDF
    In preparation for LHC Run 3 and 4 the ALICE Collaboration has moved to a new Grid middleware, JAliEn, and workflow management system. The migration was dictated by the substantially higher requirements on the Grid infrastructure in terms of payload complexity, increased number of jobs and managed data volume, all of which required a complete rewrite of the middleware using modern software languages and technologies. Through containerisation, self-contained binaries, managed by the JAliEn middleware, we provide a uniform execution environment across sites and various architectures, including accelerators. The model and implementation have proven their scalability and can be easily deployed across sites with minimal intervention. This contribution outlines the architecture of the new Grid workflow as deployed in production and the workflow process. Specifically shown is how core components are moved and bootstrapped through CVMFS, enabling the middleware to run anywhere fully independent of the host system. Furthermore, we examine how new middleware releases, containers and their runtimes are centrally maintained and easily deployed across the Grid, also by the means of a common build system

    Job splitting on the ALICE grid, introducing the new job optimizer for the ALICE grid middleware

    Get PDF
    This contribution introduces the job optimizer service for the nextgeneration ALICE Grid middleware, JAliEn (Java Alice Environment). It is a continuous service running on central machines and is essentially responsible for splitting jobs into subjobs, to then be distributed and executed on the ALICE grid. There are several ways of creating subjobs based on various strategies relevant to the aim of any particular grid job. Therefore a user has to explicitly declare that a job is to be split, and also define the strategy to be used. The new job optimizer service aims to retain the old ALICE grid middleware functionalities from the user’s point of view while increasing the performance and throughput. One aspect of increasing performance is looking at how the job optimizer interacts with the job queue database. A different way of describing subjobs in the database is presented, to minimize resource usage. There is also a focus on limiting communications with the database, as this is already a congested area. Furthermore, a new solution to splitting based on the locality of job input data will be presented, aiming to split into subjobs more efficiently, therefore making better use of resources on the grid to further increase throughput. Added options for the user regarding splitting by locality, such as setting a minimum limit for a subjob size, will also be explored

    Gluino Production in Electron-Positron Annihilation

    Get PDF
    We discuss the pair production of gluinos in electron-positron annihilation at LEP, in a model with soft supersymmetry breaking, allowing for mixing between the squarks. In much of the parameter space of the Minimal Supersymmetric Model (MSSM) the cross section corresponds to a ZZ branching ratio above 10−510^{-5}, even up to 10−410^{-4}. A non-observation of gluinos at this level restricts the allowed MSSM parameter space. In particular, it leads to lower bounds on the soft mass parameters in the squark sector.Comment: 24 pages LATEX plus 10 pages of figures (not included, available on request). Full postscript version available by anonymous ftp at node VSFYS1.FI.UIB.NO in subdirectory OSLAND, file BERGEN94-10.PS), Bergen Scientific/Technical Report No. 1994-1

    Measurement of quarkonium production at forward rapidity in pp collisions at √s=7 TeV

    Get PDF
    The inclusive production cross sections at forward rapidity of J/ψ , ψ(2S) , Υ (1S) and Υ (2S) are measured in pp collisions at s√=7 TeV with the ALICE detector at the LHC. The analysis is based on a data sample corresponding to an integrated luminosity of 1.35 pb‾¹ . Quarkonia are reconstructed in the dimuon-decay channel and the signal yields are evaluated by fitting the μ+μ− invariant mass distributions. The differential production cross sections are measured as a function of the transverse momentum pT and rapidity y , over the ranges 0<pT<20 GeV/c for J/ψ , 0<pT<12 GeV/c for all other resonances and for \(2.5 . The measured cross sections integrated over pT and y , and assuming unpolarized quarkonia, are: σJ/ψ=6.69±0.04±0.63 μ b, σψ(2S)=1.13±0.07±0.19 μ b, σΥ(1S)=54.2±5.0±6.7 nb and σΥ(2S)=18.4±3.7±2.9 nb, where the first uncertainty is statistical and the second one is systematic. The results are compared to measurements performed by other LHC experiments and to theoretical models

    Event-by-event mean pT fluctuations in pp and Pb–Pb collisions at the LHC

    Get PDF
    Event-by-event fluctuations of the mean transverse momentum of charged particles produced in pp collisions at TeX TeX 0.9, 2.76 and 7 TeV, and Pb–Pb collisions at TeX TeX 2.76 TeV are studied as a function of the charged-particle multiplicity using the ALICE detector at the LHC. Dynamical fluctuations indicative of correlated particle emission are observed in all systems. The results in pp collisions show little dependence on collision energy. The Monte Carlo event generators PYTHIA and PHOJET are in qualitative agreement with the data. Peripheral Pb–Pb data exhibit a similar multiplicity dependence as that observed in pp. In central Pb–Pb, the results deviate from this trend, featuring a significant reduction of the fluctuation strength. The results in Pb–Pb are in qualitative agreement with previous measurements in Au–Au at lower collision energies and with expectations from models that incorporate collective phenomena

    UPAYA MENINGKATKAN MOTIVASI BELAJAR SISWA MELALUI MEDIA GAME EDUCATION DALAM PEMBELAJARAN IPS DI MTs HASBUR RACHMAN ALIF DESA LENGKONG WETAN KABUPATEN MAJALENGKA

    Get PDF
    ASEP SAMSUL MA'ARIF : Berdasarkan Observasiawal di kelas VII MTs Hasbur Rachman Alif terlihat proses pembelajaran IPS masih menggunakan media spidol dan papan tulis. Sehingga banyak siswa yang kurang memperhatikan guru pada saat proses pembelajaran., Hal ini berakibat pada kejenuhan dan kebosanan yang berdampak pada hasil belajar siswa yang kurang dari KKM yang diterapkan di MTs Hasbur Rachman Alif yakni 70. Tujuan penelitian ini untuk mengetahui bagaimana penerapan pembelajaran dengan menggunakan media Game Education pada mata pelajaran IPS Terpadu, aktivitas siswa dan kinerja guru dengan pembelajaran dengan menggunakan media Game Education, dan mengetahui motivasi belajar siswa sebelum dan setelah diterapkannya pembelajaran dengan menggunakan media Game education pada mata pelajaran IPS Terpadu di MTs Hasbur Rachman Alif. Pembelajaran dengan menggunakan media Game Education menekankan motivasi siswa untuk berpikir kritis dan menuangkan. Hal ini memudahkan siswa untuk mengakses materi IPS yang banyak dimanapun, serta mempemudah daya ingat siswa tentang apayatgtelah didapatkan selama proses pembelajaran. Penelitian ini menggunakan Penelitian Tindakan Kelas (pTK) yang dilaksanakan selama tiga siklus. Teknik Pengumpulan data menggunakan observasi, tes, dan dokumentasi. Subjek penelitian ini adalah siswa kelas VII MTs Hasbur Rachman Alif sebanyak 31 siswa yang terdiri dari 18 siswa laki-laki dan 13 siswa perempuan. Pembelajaran dengan menggunakan media Game Education dapat meningkatkan motivasi belajar siswa hal ini terlihat dari hasil tes yang telah dilakukan selama tiga siklus, dimana pada pratindakan (pretes) nilai sebesar 65,25 dan ketuntasan belajar 25 yo, siklus I nilai rata-rata sebesar 76,75 dan ketuntasan_ belajar siswa sebesar 65,5%o siklus II nilai rata-rata siswa 85,75 dan nilai ketuntasan belajar sebesar 90% siklus III dengan nilai rata-rata 92,25 dan ketuntasan belajar mengalami peningkatanya itu 97,5yo. Dengan demikian dapat disimpulkan bahwa pembelajaran dengan menggunakan media Game Education merupakan salah satu upaya untuk meningkatkan hasil belajar siswa pada mata pelajaran IPS Terpadu di MTs Hasbur Rachman Alif. Kata Kunci: Game Education, MotivasiBelajar, PTK

    Suppression of ψ(2S) production in p-Pb collisions at √sNN=5.02 TeV .

    Get PDF
    The ALICE Collaboration has studied the inclusive production of the charmonium state ψ(2S) in proton-lead (p-Pb) collisions at the nucleon-nucleon centre of mass energy √sNN = 5.02TeV at the CERN LHC. The measurement was performed at forward (2.03 < ycms < 3.53) and backward (−4.46 < ycms < −2.96) centre of mass rapidities, studying the decays into muon pairs. In this paper, we present the inclusive production cross sections σ (2S), both integrated and as a function of the transverse momentum pT, for the two ycms domains. The results are compared to those obtained for the 1S vector state (J/ψ), by showing the ratios between the production cross sections, as well as the double ratios [σ (2S)/σJ/ ]pPb/[σ (2S)/σJ/ ]pp between p-Pb and proton-proton collisions. Finally, the nuclear modification factor for inclusive ψ(2S) is evaluated and compared to the measurement of the same quantity for J/ψ and to theoretical models including parton shadowing and coherent energy loss mechanisms. The results show a significantly larger suppression of the ψ(2S) compared to that measured for J/ψ and to models. These observations represent a clear indication for sizeable final state effects on ψ(2S) production

    Measurement of the Cross Section for Electromagnetic Dissociation with Neutron Emission in Pb-Pb Collisions at √sNN = 2.76 TeV

    Get PDF
    The first measurement of neutron emission in electromagnetic dissociation of 208Pb nuclei at the LHC is presented. The measurement is performed using the neutron Zero Degree Calorimeters of the ALICE experiment, which detect neutral particles close to beam rapidity. The measured cross sections of single and mutual electromagnetic dissociation of Pb nuclei at √sNN = 2.76 TeV with neutron emission are σ_single EMD = 187.2±0.2 (stat.) +13.8−12.0 (syst.) b and σ_mutual EMD = 6.2 ± 0.1 (stat.) ±0.4 (syst.) b respectively. The experimental results are compared to the predictions from a relativistic electromagnetic dissociation model.publishedVersio
    • …
    corecore