DØ (DZero) 2007

The DØ Experiment is a worldwide collaboration of scientists conducting research on the fundamental nature of matter. The experiment is located at the world’s premier high-energy accelerator, the Tevatron Collider at Fermilab in Batavia, IL. The research focuses on precise studies of interactions of protons and antiprotons at the highest available energies. It involves an intense search for subatomic clues that reveal the character of the building blocks of the universe.

In summer 2006, the DZero detector had a substantial upgrade, including the addition of new components. After any significant change to a detector, a precise calibration is required to properly quantify subsequent data. DZero’s recalibration, completed in January 2007, involved measuring, reconstructing and comparing millions of data events.

The events used in calibration do double duty: in order to be used in physics analyses, they must first be “reprocessed” using the new calibration values. In other words, during the calibration, this data was used to refine the reconstruction “recipe”; subsequently, this same (raw) data was reprocessed using the new-and-improved recipe.

The experiment itself also did double duty – DZero’s local computing farm was busy with incoming data and unable to accommodate all the needed calculations. Part of the needed computing power came from DZero’s internationally distributed computing resources, DZero-SAM, and the Worldwide Large Hadron Collider Computing Grid. However, the bulk of reprocessing took place on twelve shared Open Science Grid (OSG) sites via opportunistic access. On OSG, DZero sustained execution of over 1,000 simultaneous jobs, and consumed and produced hundreds of gigabytes of data.




Universidad de Buenos Aires

CBPF/LAFEX; Universidade do Estado do Rio de Janeiro; Universidade Estadual Paulista

McGill University; Simon Frazer University; University of Alberta; York University

IHEP, Beijing; University of Science and Technology of China

Universidad de Los Andes

Czech Republic:
Charles University/Center for Particle Physics, Prague; Czech Technical University; Czech Academy of Sciences/Institute of Physics

Universidad San Francisco de Quito

Centre de Physique des Particules de Marseille; DAPNIA/SPP, SACLAY; Institut de Physique Nucleaire de Lyon; IPHC Strasbourg; Laboratoire de I Accelerateur Lineaire; LPC, Univ Blaise Pascal, Clermont-Ferrand; LPNHE, Universites Paris VI and VII; LPSC, Grenoble

University of Wuppertal/Fachbereich Physik; Institut fuer Physik, Mainz; Ludwig-Maximilians-Universität München; Bonn University/Physikalisches Institut; Universitaet Freiburg/Physikalisches Institut; Rheinisch-Westfälische Technische Hochschule (Aachen); Ill. Phys. Institute

Delhi University; Panjab University; Tata Institute of Fundamental Research

University College Dublin

Korea University; Kyungsung University; Seoul National University; SungKyunKwan University


NIKHEF; Radboud University Nijmegen

Institute for High Energy Physics; Institute for Theoretical & Experimental Physics; Joint Institute for Nuclear Research; Moscow State University; Petersburg Nuclear Physics Institute

KTH – The Royal Institute of Technology; Lund University; Stockholm University; Uppsala University

Universität Zürich

Imperial College, London; Lancaster University; University of Manchester

Boston University; Brookhaven National Laboratory; Brown University; California State University, Fresno; Columbia University; FermiLab; Florida State University; Indiana University; Iowa State University; Kansas State University; Langston University; Lawrence Berkeley National Laboratory; Louisiana Tech University; Michigan State University; Northeastern University; Northern Illinois University; Northwestern University; Oklahoma State University; Princeton University; Purdue University; Purdue University Calumet; Rice University; Southern Methodist University; State University of New York, Buffalo; State University of New York, Stony Brook; Texas A&M University; University of Arizona; University of California, Davis; University of California, Riverside; University of Hawaii; University of Illinois at Chicago; University of Kansas; University of Maryland; University of Michigan; University of Mississippi; University of Nebraska; University of Notre Dame; University of Oklahoma; University of Rochester; University of Texas, Arlington; University of Virginia; University of Washington

Ho Chi Minh City Institute of Physics