RBC-UKQCD

RBC-UKQCD
Name	RBC-UKQCD
Established	1990s
Focus	Lattice quantum chromodynamics, hadronic physics
Headquarters	United Kingdom; United States; Japan
Members	International collaboration of physicists

RBC-UKQCD is an international collaboration of theoretical physicists and computational scientists focused on lattice quantum chromodynamics and hadronic matrix elements. The collaboration combines expertise from institutions across the United Kingdom, the United States, Japan, Canada, Germany, Italy, Switzerland, France, Spain, Netherlands, and Australia to perform large-scale numerical simulations relevant to particle physics, nuclear physics, and tests of the Standard Model.

Background and Formation

The collaboration traces its lineage to groups active in lattice gauge theory at institutions such as Rutgers University, Brookhaven National Laboratory, University of Edinburgh, University of Glasgow, Columbia University, Riken, University of Tokyo, Brookhaven National Laboratory, Yukawa Institute for Theoretical Physics, University of Southampton, University of Liverpool, and University of Washington. It formed through links between the earlier RBC effort and the UKQCD consortium, merging traditions from researchers affiliated with laboratories like Fermilab, Argonne National Laboratory, SLAC National Accelerator Laboratory, Lawrence Berkeley National Laboratory, Los Alamos National Laboratory, TRIUMF, and universities including University of Cambridge, University of Oxford, University of Manchester, Imperial College London, University of California, Berkeley, Massachusetts Institute of Technology, Princeton University, Yale University, Harvard University, Stanford University, University of California, Santa Barbara, University of California, San Diego, University of Illinois Urbana-Champaign, University of Minnesota, University of Arizona, University of Colorado Boulder, McGill University, University of Toronto, Purdue University, Ohio State University, and University of Michigan. Early governance and scientific advisory roles often connected with agencies and institutions such as Science and Technology Facilities Council, National Science Foundation, Department of Energy (United States), Japan Society for the Promotion of Science, European Research Council, and national laboratories.

Research Focus and Methodologies

The collaboration concentrates on computing nonperturbative quantities in quantum chromodynamics using lattice discretizations and chiral fermion formulations associated with advances by researchers at Columbia University and Brookhaven National Laboratory. Key methodological pillars include simulations employing domain wall fermions, formulations connected to the Nielsen–Ninomiya theorem and approaches by groups at Yukawa Institute for Theoretical Physics, use of improved gauge actions from studies at University of Tokyo, and techniques for renormalization influenced by work at CERN, DESY, KEK, INFN, CERN Theory Division, Max Planck Institute for Physics, Institut de Physique Théorique, CEA Saclay, and CEA. Numerical algorithms and codebases reflect contributions from collaboratives at USQCD, QCDOC projects, and computational frameworks developed at IBM research centers, Intel Corporation research groups, and teams at NVIDIA. Statistical analysis methods draw on practices from researchers at Cambridge Philosophical Society, Royal Society, and methodology exchanges with groups at Stanford Linear Accelerator Center and International Centre for Theoretical Physics.

Major Collaborations and Projects

RBC-UKQCD participates in multi-institutional projects and joint ventures with experimental and theoretical programs linked to CERN, ATLAS experiment, CMS experiment, LHCb experiment, Belle II, KOTO experiment, NA62 experiment, J-PARC, Jefferson Lab, COMPASS experiment, HERMES, ALICE experiment, DUNE, Hyper-Kamiokande, IceCube Collaboration, MINERvA, T2K experiment, and national grid projects like PRACE, XSEDE, DiRAC, HPC Wales, NERSC, and TSUBAME. Internal projects have included flagship calculations of weak matrix elements, kaon mixing, CP violation parameters following theoretical programs inspired by analyses at CERN Theoretical Physics Department, inputs for global fits performed by groups at CKMfitter and UTFit, and participation in working groups associated with Particle Data Group, Flavour Lattice Averaging Group, European Strategy for Particle Physics, and collaborations with experimentalists at Bristol Particle Physics Group, Glasgow Particle Physics Group, Edinburgh High Energy Physics Group, and Liverpool High Energy Physics Group.

Key Results and Contributions

The collaboration has produced precision determinations of kaon mixing parameters, neutral kaon indirect CP violation measures, hadronic matrix elements for K→ππ decays, and form factors relevant to semileptonic decays; these results have been cited in global fits alongside inputs from CKMfitter and UTFit. Influential outputs include nonperturbative renormalization factors used by phenomenologists at CERN, lattice determinations of the kaon bag parameter paralleling analyses from BNL and FNAL/MILC collaborations, and nucleon structure studies informing neutrino interaction modeling relevant to DUNE and T2K. Publications have engaged with topics central to flavor physics programs at Belle II and LHCb and theoretical questions raised in reports from European Organization for Nuclear Research panels and advisory committees associated with Science and Technology Facilities Council.

Organizational Structure and Funding

The collaboration organizes via spokespersons, management boards, and topical working groups with membership from universities and national laboratories, reflecting governance models common at CERN and DOE-funded consortia. Funding streams have included grants and contracts from Science and Technology Facilities Council, National Science Foundation, Department of Energy (United States), Japan Society for the Promotion of Science, European Research Council, national funding bodies in Italy and Germany, and support from institutional computing allocations at laboratories such as Brookhaven National Laboratory, Lawrence Berkeley National Laboratory, Fermilab, and Riken. Collaboration meetings and workshops have been held at venues including CERN, Riken, Yukawa Institute for Theoretical Physics, Perimeter Institute, KITP, ICTP, Les Houches Summer School, and university hosts like University of Cambridge and Imperial College London.

Computational Resources and Facilities

Large-scale simulations rely on supercomputing resources and specialized hardware including QCD-dedicated machines influenced by the QCDOC architecture, clusters at Brookhaven National Laboratory, petascale systems at Argonne National Laboratory, allocations at Oak Ridge Leadership Computing Facility, time on NERSC machines, and GPU clusters provided through allocations with XSEDE and national HPC centers such as PRACE. Code and software infrastructure are developed collaboratively with contributions from USQCD Collaboration, porting efforts for CUDA and OpenCL ecosystems supported by vendors like NVIDIA and AMD, and performance tuning guided by research groups at Intel and IBM Research. Data produced are shared through community practices mirrored by repositories associated with HEPData and analysis frameworks used across collaborations at CERN and major university groups.

Category:Particle physics collaborations