Last updated: September 26 2007 10:09:56
Task 3.2 High Energy Physics Applications  

High Energy Physics Applications

One of the main challenges for High Energy Physics (HEP) is to answer long-standing questions about the fundamental particles of matter and the forces acting between them. The HEP area has a long tradition of high demanding applications and has leaded the development of Grid technologies since the very beginning. The HEP community has already proven its ability to profit from distributed computing and storage, and therefore not only to use, but also to lead the development of Grid technologies.

The EGEE project has identified HEP as one of the two specific areas where efforts on Grid technologies will be focused. Similarly, EELA has selected HEP applications as one of the areas where the project can be useful and show its capabilities.

The future LHC experiments will generate a vast amount of data, which need to be processed both on-line and off-line. On the other hand, the research on new and known physics is based on the comparison of data and MC events previously simulated. Typically large simulations of the production of new elementary particles in collisions in accelerators are required. The information recorded in the detector for a single collision is called an event, and its size may vary up to several hundreds of Mbytes, and includes a large number of measured and derived variables. Given the huge size of both samples (real and simulated data) and small ratio of the interesting events, special CPU intensive filtering techniques are needed as part of the analysis process. All the experiments have already developed grid-enabled software to cope with these requirements.

The HEP community is growing in Latin America with institutions from various Latin-American countries participating in Particle Physics experiments around the world, particularly the LHC at CERN, but also at DESY, at the Tevatron and in the Pierre Auger Observatory. Both UFRJ and UNAM already participate in LHC experiments (LHCb and ALICE) and have responsibilities demanding extensive use of computing and storage power. Around 120 Gb of the total LHCb production was done using the computers in Brazil. The UNAM is integrating its computing resources for ALICE into the Grid structure of the collaboration for participation in future MC production. Besides these batch oriented applications, some of the European partners (for example, CSIC) have participated in the CrossGrid project with a clear emphasis on interactivity in HEP applications as one of the cases included. UTFSM and UNLP have teams with a strong theoretical background and specialized on HEP applications. They had an extensive participation with some HEP applications under the AlphaGrid initiative, interconnected through GÉANT and ALICE networks, and are now partners of the ATLAS collaboration. The applications include computing on Quantum Chromo dynamics on lattices.

Given the existing collaborations of the partners, EELA has identified two kind of application in the HEP that can be deployed easily and reliably on the project infrastructure:

  • MC production: The LHC experiments are already producing MC events that will be further used in the analysis. MC calculations are an ideal Grid application because of the independence of the individual events. This has lead to an early, successful use of the Grid infrastructure for large scale MC production, as demonstrated by the success of the LHC data challenges. The EELA infrastructure will allow the integration of European and Latin American resources provided by the LHC collaborators on all three continents.

  • Interactive Analysis: Grid-aware applications using large, distributed databases for High-Energy Physics have to be set up and deployed. The challenges for this kind of applications are: seamless access to large, distributed databases in the grid environment, development of distributed data-mining techniques suited to the HEP field, and integration with a user-friendly interface, which could include specific portal and web tools. As indicated in the CERN LHC Computing Review Report, the development of interactive data analysis tools is the area where joint efforts among one or more experiments take place, resulting in common projects and products, might lead to cost savings, or decreased risks, or both.
The applications already selected to run on the EELA infrastructure are ALICE and LHCb, but ATLAS and CMS will hopefully follow soon. In addition, when the Auger Access Project will be ready, the Pierre Auger Experiment will be also an application to be included in EELA.
OBJECTIVES
The HEP area of the EELA project aims at extending the currently existing experience on both sides of the Atlantic Ocean to the rest of L.A., attracting new users in the area and facilitating the research on particle physics. The deployment of an interactive analysis Grid enabled application based on the CrossGrid experience together with the expansion of the MC simulation are the two main efforts in this area. EELA aims to set up a framework, where specialized groups of researchers can develop, test and deploy HEP applications by using a common infrastructure. This will improve the current exchanging of information and solutions between the groups.
EXPECTED RESULTS
  • The running of at least two EGEE HEP applications (one for ALICE and one for LHCb) in the EELA Pilot Testbed. These applications will be exploited in order to disseminate the Grid culture on the Latin American Partners (UNAM, UFRJ, UTFSM and UNLP) and to touch the feelings of the Latin-American Scien ce and Technology authorities.

  • The exploration of at least one enhanced interactive analysis application.

  • The integration of the European and Latin American HEP communities, fostering the already existing collaborations between Latin-American groups and the LHC programme at CERN.

  • The establishment of an expert group with EGEE know-how in Latin America in order to develop EGEE aware applications shared between Latin America and Europe.


ALICE (A Large Ion Collider Experiment)

Hosted at CERN, the ALICE collaboration is building a dedicated heavy-ion detector to exploit the unique physics potential of nucleus-nucleus interactions at LHC energies. The aim is to study the physics of strongly interacting matter at extreme energy densities, where the formation of a new phase of matter, the quark-gluon plasma, is expected. It uses the EGEE Baseline Services for workload management, reliable file transfer (FTS), LCG File Catalogue (LFC) and Storage Resource Manager (SRM) within the framework of so-called VO-boxes, provided at sites for delivering application-dependent services. Overall ALICE reported a stable set of central services for production including the ALICE-specific VO-Box software. To provide a stable and evolutionary platform and a user entry point into the Grid world, ALICE has developed the AliEn (AliCE Environment) framework with the aim of offering to the ALICE user community transparent access to computing resources distributed worldwide. The system is built around Open Source components and uses the Web Services model and standard network protocols. It implements a distributed computing environment that has been used to carry out the production of Monte Carlo data at over 30 sites in four continents.

LHCb (Large Hadron Collider beauty experiment)

The aim of the LHCb experiment is to full investigate the CP violation in the Bd and Bs systems to possibly renew the physics beyond the standard model. It is a specialized experiment that makes use of the fact that mesons that contain a b-quark will be copiously produced at the LHC. It turns out that these mesons are most likely to be produced close to the incoming beams' direction. In this way, the LHCb detector is designed to catch these low-angle particles.
The LHCb application for simulation (GAUSS), digitalization (BOOLE), reconstruction (BRUNEL) and analysis (DaVinci) are build upon a common software framework called Gaudi. They share a common Event Model that is used for data persistence throughtout the LCG pool software. The use of a LCG Grid will perform distributed analysis of the simulated data. A number of central services were deployed whose key services are: A production database where all prepared jobs to be run are stored; A Workload Management System that dispatches jobs to all the sites according to a "pull" paradigm; Monitoring and Accounting services that are necessary to follow the progress of the Data Challenge and allow the breakdown of resources used; and, A Bookkeeping service and the AliEn File Catalog (FC) to keep track of all datasets produced during the Data Challenge.

FUTURE APPLICATIONS

EELA is promoting the inclusion of new HEP applications according to the increasing number of communities in both Latin America and Europe interested in joining it. Thus, the favourite candidate experiments are:

- ATLAS, a general-purpose experiment for recording proton-proton collisions at the LHC with a detector design that has been optimized to cover the largest possible range of LHC physics;

- CMS (Compact Muon Solenoid), a detector for the search of the SM Higgs boson allowing the detection of a wide range of possible signatures from alternative electro-weak symmetry breaking mechanisms too; and - The Pierre Auger project, where the study of the universe's highest energy particles, which shower down on Earth in the form of cosmic rays is made in an international facility sited in Argentina.
These experiments are expected to join EELA very soon.

References

- CERN, European Organization for Nuclear Research

- LHC, http://lhc.web.cern.ch/lhc/

- The ALICE experiment, http://aliceinfo.cern.ch/index.html

- ATLAS, http://atlas.web.cern.ch/Atlas/index.html

- CMS, http://cmsinfo.cern.ch/Welcome.html/

- LCG, http://lcg.web.cern.ch/LCG/

- AliEn, http://alien.cern.ch/

- AliEn, http://glite.web.cern.ch/glite/alien/

- ARDA, http://lcg.web.cern.ch/LCG/peb/arda/Default.htm

- PROOF, M. Ballintijn, R. Brun, F. Rademakers with PROOF, Proc. of TUCT004.

- GAUSS, http://lhcb-comp.web.cern.ch/lhcb-comp/Simulation/default.htm

- BOOLE, http://lhcb-comp.web.cern.ch/lhcb-comp/Digitization/default.htm

- BRUNEL, http://cern.ch/lhcb-comp/Reconstruction/default.htm

- DaVinci, http://lhcb-comp.web.cern.ch/lhcb-comp/Analysis/default.htm

- Gaudi, http://cern.ch/proj-gaudi/welcome.html

- DIRAC, http://lhcb-comp.web.cern.ch/lhcb-comp/DIRAC/DPI/docs/DIRAC_PI_v1.doc

- HELEN, http://omnis.if.ufrj.br/~helen/HELEN_finalproject.doc

Dissemination Activities

    • Two Information Sheets
    • Madrid (Spain), EELA KoM and 1st Workshop, 1-2 February 2006
      • A presentation of the EELA HEP Applications
    • Madrid (Spain), ALICE-CIEMAT Meeting, 4 May 2006
      • A presentation of the status of the EELA HEP Applications
    • Itacuruçá (Brazil), EELA 3rd Workshop, 24-25 June 2006
      • A presentation of the status of the EELA HEP Applications
    • Santiago (Chile), 1st EELA Conference, 4-5 September 2006
      • A presentation of the status of the EELA HEP Applications
    • Geneva (Switzerland), EGEE06 Conference, 25-29 September 2006
      • A presentation of the deployment of the EELA Applications in the SEE-GRID Regional Grids Workshop
    • Granada (Spain), Jornadas Técnicas RedIRIS 2006 y XXII Grupos de Trabajo, 13-17 November 2006
      • A presentation of the EELA Applications
    • Lima (Peru), EELA 4th Workshop, 11-12 January 2007
      • A presentation of the status of the EELA HEP Applications
    • Abarca, et al. Building a Network in Latin America: e-Infrastructure and Applications. Proceedings of the Spanish Conference on e-Science Grid Computing 1, 83-96 (2007)
    • Bogotá (Colombia), EELA 5th Workshop, 5 March 2007
      • A presentation of the status of the EELA Applications
    • La Plata (Argentina), EELA 6th Workshop, 29-30 March 2007
      • A presentation of the status of the EELA Applications
    • Manchester (UK), EGEE User Forum, 9-11 May 2007
      • A presentation of BiG
      • A presentation of the EELA applications
    • Maputo (Mozambique), IST-Africa, 9-11 May 2007
      • A presentation of the EELA applications
      • Paper in Proceedings of IST-Africa Conference
    • Santiago de Compostela (Spain), IBERGRID Conference, 14-16 May 2007
      • A presentation of the EELA applications
      • Paper in Proceedings of IBERGRID Conference 1, 29-35 (2007)
    • Rio de Janeiro (Brazil), LAGrid Conference, 14-17 May 2007
      • A presentation of the the status of the EELA applications
      • Paper in Proceedings of the LAGrid conference
    • Varadero (Cuba), EELA Workshop, 29-30 May 2007
      • A presentation of the status of the EELA Applications
    • Paper in Proceedings of the NETTAB Conference 7, 145-156 (2007)
      • Rio de Janeiro (Brazil), XXVII Congresso de la SBC, 30 Jun-06 Jul 2007
    • Victoria (Canada), CHEP Conference, 2-7 September 2007
      • A presentation of the status of the EELA HEP Applications
    • Budapest (Hungary), EGEE Conference, 1-5 October 2007
      • A presentation of the status of the EELA applications
    • La Antigua (Guatemala), 7th EELA Workshop, 17 Oct 2007
      • A presentation of the status of the EELA applications
    • Mexico City (Mexico), 8th EELA Workshop, 22 Oct 2007
      • A presentation of the status of the EELA applications


    Links to slides presented in conferences, papers, posters, etc. can be found here:

    - WP3 DOCUMENTS


-
EELA DOCUMENTS
PARTICIPANTS