United States of America

Number of CERN users

1915 (January 2016)

CERN contact

E. Tsesmelis

Participation in CERN Experiments


Participation in CERN Accelerator Projects

LHC, CLIC/CTF3, LINAC4, New inner triplet for sLHC Phase I (NIT), sLHC Phase II studies

WLCG Participation

Tier-1 centres, Tier-2 centres

Collaborating Institutes

° University of Alabama
° State University of New York at Albany
° Argonne National Laboratory
° University of Arizona
° Auburn University
° Baylor University
° University of Cincinnati
° University of California Berkeley
° Lawrence Berkeley National Lab. (LBNL) Berkeley
° Boston University
° Brandeis University
° Brookhaven National Lab. (BNL), Upton
° Brown University
° SUNY Buffalo
° California Polytechnic State University
° California Institute of Technology
° Carnegie Mellon University
° Case Western University, Cleveland
° University of Chicago
° Chicago State University
° University of Colorado Boulder
° Columbia University
° Cornell University
° Creighton University
° Southern Methodist University, Dallas
° UC Davis
° Northern Illinois University, Dekalb
° Duke University, Durham
° George Mason University, Fairfax
° Fairfield University
° Fermi National Accelerator Laboratory
° University of Florida
° Florida Institute of Technology
° Florida Int. University
° Florida State University
° Hampton University
° Harvard University
° University of Houston
° University of Illinois at Chicago
° University of Indiana, Bloomington
° University of Iowa
° Iowa State University, Ames
° University of California, Irvine
° Johns Hopkins University
° Jefferson NL
° University of Kansas
° Kansas State University
° UC Los Angeles
° Livermore NL
° Louisiana Tech University
° University of Maryland
° University of Massachusetts , Amherst
° Massachusetts Institute of Technology (MIT), Cambridge
° University of Michigan, Ann Arbor
° Michigan State University
° University of Minnesota
° University of Mississipi
° University of Missouri-Rolla
° University of New Mexico, Albuquerque
° New York University
° Northeastern University
° Northwestern University
° University of Notre Dame
° Oak Ridge National Laboratory
° Ohio State University, Columbus
° OSC Ohio Supercomputer Center, Columbus (Associate ALICE)
° University of Oklahoma
° Oklahoma State University
° University of Oregon, Eugene
° University of Pennsylvania
° Penn State University
° University of Pittsburgh
° Princeton University
° University of Puerto Rico
° Purdue University
° Purdue University Calumet
° Rice University
° UC Riverside
° University of Rochester
° Rockefeller University
° Rutgers
° UC San Diego
° UC Santa Barbara
° UC Santa Cruz
° State Universtiy New York, Stony Brook
° University of Syracuse
° University of Washington, Seattle
° SLAC, Stanford
° University of Tennessee
° Texas A&M University
° Texas Tech. University
° University of Texas, Dallas
° University of Texas, Arlington
° University of Texas, Austin
° Tufts University, Medford
° University of Illinois, Urbana
° Vanderbilt University
° University of Virginia
° Wayne State University
° University of Wisconsin, Madison
° Yale University, New Haven

(Only Institutes having signed a Memorandum of Understanding with CERN are listed here. For all participating institutes, refer to the CERN greybook)

US physicists have been participating in a wide range of experiments at CERN for over 30 years, from the ISR through SPS fixed-target experiments, all the LEP experiments (L3, ALEPH, OPAL, DELPHI), heavy-ion experiments (NA45, NA49) and ISOLDE. Following the demise of the Superconducting Super Collider (SSC) in 1993, many US physicists joined ATLAS and CMS, and some have also joined ALICE and LHCb.

The US has made contributions to the LHC accelerator construction, coordinated by Fermi National Accelerator Laboratory (FNAL) and Brookhaven National Laboratory (BNL), under an Implementation Protocol that expired in 2007. The US also set up the LHC Accelerator Research Program (LARP) to support LHC commissioning, including both beam monitors and human resources, and R&D on magnets for a possible LHC upgrade. The USA is a special Observer State, with the right to attend restricted Council sessions for discussions of LHC matters.

The US contributions to ATLAS and CMS have been substantial. They were funded jointly by the Department of Energy (DOE) and the National Science Foundation (NSF) under an Implementation Protocol agreed in 1996 and finalized in 1997. The US user community has expanded, as attention has shifted away from their domestic programme with the completions of the CLEO, BABAR and soon the Tevatron experiments, and new groups have joined ATLAS and particularly CMS. Moreover the US is involved in smaller experiments such as LHCf, ACE, ALPHA, CAST, CLOUD, COMPASS, NA61, NA62, nTOF and TOTEM.

The US has also contributed to the development of the WLCG and operates two Tier-1 Centres and 14 Tier-2 Centres.

Groups from the SLAC National Accelerator Laboratory and Northwestern University already participate in the CLIC R&D programme, and the DOE has undertaken to strengthen this activity. There is also a US participation in LINAC4.