USQCD BSM Collaboration

Project

The USQCD BSM Collaboration is composed of members of the USQCD Collaboration who are using lattice gauge theory to study physics beyond the standard model on leadership-class machines.

Our current project studies SU(3) lattice gauge theory with Nf=8 nearly massless fermions in the fundamental representation using the Highly Improved Staggered Quark (HISQ) action. Through the Innovative and Novel Computational Impact on Theory and Experiment (INCITE) program of the U.S. Department of Energy, we are currently generating 323x64 and 483x96 configurations on the Intrepid Blue Gene/P supercomputer at the Argonne Leadership Computing Facility. We plan to complete this project by generating 643x128 configurations.

These ensembles, featuring larger volumes and lighter masses than obtained previously, will be used to calculate many physically interesting quantities including the light hadron spectrum, static quark potential, Dirac eigenvalues, running gauge couplings, glueballs, precision electroweak observables, and the scale dependence of the chiral condensate relevant to the problem of flavor-changing neutral currents in technicolor theories.

Participants

  • T. Appelquist (Yale U.)
  • R. C. Brower (Boston U.)
  • S. M. Catterall (Syracuse U.)
  • M. Clark (NVIDIA)
  • J. T. Giedt (Rensselaer Polytechnic Institute)
  • K. M. Holland (U. of the Pacific)
  • J. G. Kuti (U. of California, San Diego)
  • H. Na (Argonne National Lab)
  • J. C. Osborn (Argonne National Lab)
  • D. Schaich (U. of Colorado, Boulder)
  • D. K. Sinclair (Argonne National Lab)
  • G. Voronov (Yale U.)
  • R. Babich (NVIDIA)
  • M. I. Buchoff (Lawrence Livermore National Lab)
  • M. Cheng (Boston U.)
  • G. T. Fleming (Yale U.)
  • A. Hasenfratz (U. of Colorado, Boulder)
  • J. E. Kiskis (U. of California, Davis)
  • M. F. Lin (Yale U.)
  • E. T. Neil (Fermi National Accelerator Lab)
  • C. Rebbi (Boston U.)
  • C. Schroeder (Lawrence Livermore National Lab)
  • P. M. Vranas (Lawrence Livermore National Lab)
  • O. Witzel (Boston U.)

Organization

Participants in the USQCD BSM Collaboration are asked to join the "latticebsm" email list managed by . We hold regular weekly conferences through EVO, currently scheduled for 11:00 Eastern every Wednesday. Informal notes from these meetings are distributed for those unable to participate, and additional information is often posted on the internal pages of this site.

Software

We used MIMD Lattice Computation (MILC) Collaboration software during the initial stages of our current project. Eight-fermion calculations require a much stronger bare coupling than lattice QCD, and we discovered that at such strong bare coupling the HISQ action as implemented in this software is much more computationally expensive than we anticipated. To address this, we have used the new QHMC (a.k.a. FUEL) framework to more easily explore, modify, evaluate and tune our algorithms. By combining several algorithmic improvements and optimizations, we have obtained roughly a factor of eight speedup on small lattice volumes, and we are currently carrying out the corresponding optimizations for our largest volumes. While QHMC is built on the standard USQCD software libraries, it remains under active development.

Data

Our primary production runs use overlapping ranges of fermion masses on 163x32, 243x48, 323x64 and 483x96 lattice volumes. (323x64 and 483x96 ensembles are not yet complete.) In addition, on other resources we are carrying out finite-temperature studies using a wider range of volumes. Our saved configurations are available to any USQCD Collaboration member .

Last modified 26 April 2012 by

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