FNAL Lattice and MILC collaborations

FNAL Lattice and MILC collaborations
Name	FNAL Lattice and MILC collaborations
Formation	1990s–2000s
Headquarters	Fermilab, University of Illinois at Urbana–Champaign
Fields	Particle physics, High-energy physics, Quantum chromodynamics
Members	researchers from Fermilab, MILC Collaboration, University of Washington, Columbia University, Massachusetts Institute of Technology

FNAL Lattice and MILC collaborations The FNAL Lattice and MILC collaborations are cooperative research programs linking Fermilab lattice efforts with the MILC Collaboration community to advance numerical studies of Quantum chromodynamics and hadronic matrix elements. The partnerships involve researchers from institutions such as University of Illinois at Urbana–Champaign, University of Washington, Columbia University, Massachusetts Institute of Technology, and Brookhaven National Laboratory, working on problems relevant to experiments at Fermilab, CERN, Belle II, and J-PARC. These collaborations connect to projects supported by agencies like the U.S. Department of Energy, the National Science Foundation, the Science and Technology Facilities Council, and international programs at TRIUMF and RIKEN.

History and formation

The origins trace to lattice QCD developments in the 1990s and 2000s when groups at Fermilab and the MILC codebase contributors at University of Illinois at Urbana–Champaign coordinated with teams from Columbia University, University of Washington, Brookhaven National Laboratory, and Stony Brook University. Early interactions involved comparisons with results from collaborations such as HPQCD, RBC/UKQCD, ALPHA Collaboration, JLQCD, and CP-PACS, and engagement with experimental inputs from CDF, DØ, and BaBar. Formalized joint efforts emerged around shared use of the asqtad action, collaborations on staggered fermions methodology, and cross-validation with studies from European Twisted Mass Collaboration and ETM Collaboration.

Research goals and methodology

Primary goals include precision determinations of hadron spectra, decay constants, form factors, and weak matrix elements to support flavor physics programs at Fermilab, CERN, KEK, and Belle II. Methodologies combine algorithmic advances from groups like Lüscher-inspired finite-volume techniques, implementation of improved actions such as Highly Improved Staggered Quarks, and nonperturbative renormalization strategies used by ALPHA Collaboration and RBC/UKQCD. The collaborations employ cross-checks against results from HPQCD, Fermilab Lattice and MILC's contemporaries, comparisons with perturbative calculations by Brodsky-style approaches, and engagement with phenomenology from Flavor Lattice Averaging Group and CKMfitter.

Key results and contributions

Notable contributions include high-precision calculations of the B meson decay constants f_B and f_{B_s}, semileptonic form factors for B→πℓν and D→Kℓν decays, and hadronic matrix elements entering determinations of the CKM matrix elements |V_cb| and |V_ub|. These results interfaced with global fits by CKMfitter and UTfit and informed interpretations of measurements from LHCb, Belle II, BaBar, and CLEO-c. The collaborations produced benchmark ensembles that complemented gauge configurations from RBC/UKQCD, JLQCD, and ETM Collaboration, and motivated theoretical advances linked to work by Symanzik, Sheikholeslami–Wohlert, and Wilson.

Computing infrastructure and software

Computing relied on high-performance systems at Fermilab, national computing centers like NERSC, ALCF, and OLCF, and institutional clusters at University of Illinois at Urbana–Champaign and Columbia University. Software stacks integrated the MILC code with solvers inspired by Lüscher techniques, multigrid algorithms from Brannick-style developments, and workflow tools used at Argonne National Laboratory and Brookhaven National Laboratory. Data management aligned with protocols from Open Science Grid and job scheduling systems employed at XSEDE and PRACE facilities.

Collaboration structure and funding

Organizationally, work is coordinated through principal investigators at Fermilab, co-leads from University of Illinois at Urbana–Champaign and partner institutions such as Columbia University, Massachusetts Institute of Technology, University of Washington, and Yale University. Funding streams include awards from the U.S. Department of Energy, grants from the National Science Foundation, support from DOE Office of Science program offices, and collaborations with international funders like STFC and national agencies at Japan Society for the Promotion of Science and Natural Sciences and Engineering Research Council of Canada. Governance mirrors models used by HPQCD and RBC/UKQCD with working groups for spectra, heavy-quark physics, and algorithm development.

Major publications and impact

Major publications appeared in journals such as Physical Review Letters, Physical Review D, Journal of High Energy Physics, and Physics Letters B, and were cited by phenomenology reviews from Particle Data Group and global fit analyses by CKMfitter and UTfit. Results influenced experimental strategies at LHCb, Belle II, and Fermilab’s neutrino and flavor programs, and were discussed at conferences like Moriond, Lattice Conference, ICHEP, and EPS-HEP. The collaborations’ ensembles and codes have been reused by groups including HPQCD, RBC/UKQCD, ETM Collaboration, and JLQCD.

Outreach and training initiatives

Training efforts include mentoring graduate students and postdoctoral researchers from University of Illinois at Urbana–Champaign, Columbia University, Massachusetts Institute of Technology, University of Washington, and Yale University, organizing tutorials at the Lattice Conference and workshops at Fermilab and Brookhaven National Laboratory, and contributing to summer schools such as Les Houches Summer School and Saas-Fee Advanced Course. Outreach activities include public lectures at Fermilab and collaborative presentations at meetings hosted by APS and IHEP.

Category:Lattice quantum chromodynamics collaborations