Fermilab Lattice and MILC Collaborations

Fermilab Lattice and MILC Collaborations

The Fermilab Lattice and MILC Collaborations are collaborative consortia of researchers from institutions such as Fermilab, Brookhaven National Laboratory, Argonne National Laboratory, Lawrence Berkeley National Laboratory, Los Alamos National Laboratory and universities like University of Illinois at Urbana–Champaign, Columbia University, University of Washington, and University of Colorado Boulder. The groups have contributed to lattice gauge theory calculations informing experiments at facilities including Large Hadron Collider, SLAC National Accelerator Laboratory, KEK, and J-PARC. Their work is cited alongside results from collaborations such as HPQCD Collaboration, RBC and UKQCD Collaborations, ETM Collaboration, CLS Consortium, and ALPHA Collaboration.

History and Collaboration Structure

The origins trace to methodological developments at Fermilab and the longstanding MILC (MIMD Lattice Computation) effort originating from University of Illinois at Urbana–Champaign and collaborators from Rutgers University, University of Arizona, University of California, Santa Barbara, and University of Utah. Early influences include numerical work from Kenneth G. Wilson and initiatives at Brookhaven National Laboratory and Los Alamos National Laboratory that informed software frameworks such as the MILC code and community libraries adopted by groups like USQCD. Organizationally, governance has resembled consortia models used by CERN experiments and by collaborations such as DZero, CDF, BaBar, and Belle in coordinating analysis, led by principal investigators affiliated with institutions including Indiana University and University of California, Berkeley.

Research Focus and Key Results

Research concentrates on ab initio calculations in Quantum Chromodynamics using lattice discretizations to compute hadronic matrix elements, decay constants, and scattering amplitudes relevant to flavor physics programs at Belle II, LHCb, CMS, and ATLAS. Notable outputs include determinations of the CKM matrix elements that intersect with global fits from groups like UTfit and the CKMfitter Group, Standard Model tests tied to muon g-2 tensions reported by Muon g-2 Experiment at Fermilab and precision inputs for neutrinoless double beta decay matrix elements used by GERDA and CUORE. Results have influenced interpretations of anomalies discussed at conferences such as ICHEP, Moriond, Lattice Conference, and Rencontres de Blois, and are compared with phenomenology from groups at Princeton University, Massachusetts Institute of Technology, Harvard University, and Stanford University.

Computational Methods and Lattice Techniques

Methodologies employ improved staggered fermions, domain-wall fermions, and HISQ actions developed with input from theorists at Columbia University and Yale University, leveraging solver algorithms pioneered in collaborations with NVIDIA GPU efforts and supercomputing centers like Argonne Leadership Computing Facility, Oak Ridge Leadership Computing Facility, National Energy Research Scientific Computing Center, and Texas Advanced Computing Center. Techniques incorporate gauge ensembles generated with algorithms related to Hybrid Monte Carlo used in projects influenced by work at University of Edinburgh and Swansea University, and use perturbative matching approaches connecting to continuum schemes like MS-bar used in calculations by groups at CERN and DESY. Software stacks interoperate with community projects like QUDA and standards from MPI and libraries supported by DOE Office of Science initiatives.

Major Projects and Publications

Major projects include large-scale ensembles of gauge configurations whose results appear in peer-reviewed journals alongside analyses from Physical Review Letters, Physical Review D, Journal of High Energy Physics, and conference proceedings for Lattice 20XX series. High-impact publications have addressed meson decay constants relevant to B meson and D meson phenomenology, quark-mass determinations cross-checked with global analyses by Particle Data Group, and contributions to nucleon structure relevant for neutrino oscillation experiments at NOvA and DUNE. Collaborative papers often list coauthors from University of Glasgow, University of Southampton, University of Cambridge, Imperial College London, Trinity College Dublin, University of Toronto, and McGill University.

Funding, Partnerships, and Infrastructure

Funding has come from agencies such as the U.S. Department of Energy, National Science Foundation, and institutional grants from laboratories including Fermilab and Brookhaven National Laboratory, alongside European partners funded by European Research Council awards and national agencies like STFC and CNRS. Partnerships extend to hardware vendors including Intel, AMD, and NVIDIA for co-design efforts, and to supercomputing centers such as NERSC, OLCF, and ARL-supported facilities. Infrastructure relies on data management practices compatible with repositories used by collaborations like HEPData and computational frameworks coordinated with initiatives at USQCD and transnational projects organized through meetings at KITP and ICTP.

Category:Lattice quantum chromodynamics