USQCD — LLMpedia

USQCD
Name	USQCD Collaboration
Formation	2000s
Type	Scientific collaboration
Purpose	Lattice quantum chromodynamics research
Headquarters	United States
Region served	International
Parent organization	Department of Energy (DOE)

Contents

USQCD USQCD is a United States-based consortium for lattice quantum chromodynamics research that coordinates computational resources, software, and scientific programs across national laboratories and universities. The collaboration connects researchers working at national laboratories such as Fermilab, Brookhaven National Laboratory, Argonne National Laboratory, Lawrence Berkeley National Laboratory, and Oak Ridge National Laboratory with university groups at institutions like MIT, Caltech, University of Chicago, Columbia University, and University of Washington. USQCD integrates efforts with funding agencies including the United States Department of Energy and agencies such as the National Science Foundation to support simulations on leadership-class facilities like Summit (supercomputer), Sierra (supercomputer), and Perlmutter.

Overview

USQCD organizes lattice gauge theory projects that address problems in particle physics, nuclear physics, and computational science by coordinating activities among researchers at laboratories such as Thomas Jefferson National Accelerator Facility and universities such as University of California, Berkeley, University of Colorado Boulder, University of Illinois Urbana-Champaign, Yale University, and University of California, San Diego. The collaboration develops community software stacks used on machines procured through programs like the Department of Energy Office of Science initiatives and runs code optimized for architectures from vendors such as NVIDIA, Intel Corporation, AMD, and IBM. USQCD members publish results in journals associated with organizations such as the American Physical Society, Physical Review Letters, and Journal of High Energy Physics.

The formation of the collaboration followed developments in lattice gauge theory at institutions like Brookhaven National Laboratory and Fermilab in the late 20th and early 21st centuries, influenced by pioneering work by scientists affiliated with Brookhaven, Los Alamos National Laboratory, and university groups at University of Cambridge and Harvard University. Early projects paralleled large-scale simulations at centers such as National Energy Research Scientific Computing Center and Oak Ridge Leadership Computing Facility. USQCD's development reflected trends in community software projects exemplified by efforts at CERN and collaborative models used by experiments like ATLAS and CMS.

USQCD operates with governance structures that include executive committees and working groups connecting principal investigators at labs including Brookhaven National Laboratory, Fermilab, Argonne National Laboratory, and universities such as University of Arizona and Rutgers University. Funding flows from agencies such as the United States Department of Energy and the National Science Foundation and is administered through programs similar to allocations at facilities like Oak Ridge National Laboratory and Argonne National Laboratory leadership computing. Project reviews involve panels with representatives from institutions like Lawrence Livermore National Laboratory, Sandia National Laboratories, and academic partners at Princeton University and Massachusetts Institute of Technology.

USQCD pursues precision calculations of hadronic matrix elements relevant to experiments at facilities like Fermilab, CERN, Jefferson Lab, Belle II, and LHCb. Research targets include determinations of parameters for the Cabibbo–Kobayashi–Maskawa matrix relevant to flavor physics studied at BaBar and BESIII, nonperturbative inputs for neutrino scattering relevant to DUNE (experiment), and calculations of nucleon structure for comparisons with measurements at Jefferson Lab and JLab Hall A. Programs address topics connected to theoretical frameworks developed by figures associated with Nobel Prize in Physics winners and groups from Institute for Advanced Study, Perimeter Institute, and CERN Theory Division.

USQCD users run code on supercomputers such as Summit (supercomputer), Sierra (supercomputer), Perlmutter, and earlier platforms like Titan (supercomputer) and Blue Gene/Q. The collaboration develops software components that interoperate with middleware and resource managers used at centers including National Energy Research Scientific Computing Center, Argonne Leadership Computing Facility, and Oak Ridge Leadership Computing Facility. USQCD codes are tuned for accelerators produced by NVIDIA, AMD, and vector processors designed by IBM and leverage libraries similar to those from OpenMP, MPI, and vendor toolchains from Intel Corporation and Cray Research.

USQCD collaborates with international lattice groups at institutions such as CERN, Institute of Particle Physics Phenomenology, Riken, University of Edinburgh, Humboldt University of Berlin, University of Southampton, Trinity College Dublin, and KEK. Partnerships extend to experimental collaborations at Fermilab, CERN, Belle II, and theoretical centers including Perimeter Institute, Institute for Advanced Study, and SLAC National Accelerator Laboratory. USQCD interacts with software consortia and standards bodies like OpenMP, MPI, and HPC vendors including NVIDIA and Intel Corporation to optimize codes for leadership systems.

USQCD contributions include high-precision determinations of hadron masses and decay constants used by experiments such as LHCb and Belle II, calculations informing CKM unitarity tests relevant to BaBar and Belle, and nucleon matrix element computations that impact interpreting results from DUNE and MINERvA. The collaboration has advanced software used across the community akin to major projects at CERN and demonstrated scalable performance on systems like Summit (supercomputer) and Sierra (supercomputer), supporting physics results published in outlets associated with American Physical Society and collaborations with groups at Institute of Physics. Major technical milestones paralleled developments at centers such as National Energy Research Scientific Computing Center and Oak Ridge National Laboratory.