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Title: Lattice QCD Thermodynamics First 5000 Trajectories

Abstract

These results represent the first LQCD analysis for approximately 5000 trajectories with each of the p4rhmc and milc codes, with some of the lower temperature runs having fewer. Both runs were for lattice dimensions of 32{sup 3}x8. Some 32{sup 4} T=0 jobs were also run for p4rhmc. The p4 calculation was performed with v2.0 QMP{_}MPI.X (semi-optimized p4 code using qmp over mpi) and milc version of the su3 rhmc susc eos executable dated Mar 1, 2007 on ubgl in the /usr/gapps/hip/qcd/milc/bin subdirectory (svn revision 28). As with previous runs, calculations were performed along lines of constant physics, with the light quark masses 2-3 times their physics values and the strange quark mass set by m{sub ud} = 0.1m{sub s}. Job submissions were performed using a new subSet.pl job submission script that locates current jobs and submits additional jobs with the same beta value as pending. Note that after reaching a limit of about 35 jobs subsequent submissions are delayed and will not be submitted directly from that state. The job submission script was used to submit revised versions of the milc and p4rhmc csh scripts. Initial thermalized lattices for each code were also for milc (taken from the firstPhys runs),more » but the p4rhmc runs include thermalization. The only modifications for running on BG/L were to the directory names and the mT parameter which determines job durations (24 hrs on BG/L vs. 4 hrs on ubgl). All finite temperature jobs were submitted to the 512 node partitions, and all T=0 runs were submitted to 2048 node partitions. The set of runs was plagued by filesystem errors on lscratch1 and lscratcH{sub 2}. Many jobs had to be reset (deleting the most recent output file for milc and/or lattice for p4) and resubmitted. The analysis was performed with a new set of scripts that produced a more condensed output for scanning. All scans were verified with checksums, which have been retained in the output along with the line numbers. All lattices, log files, and job submission scripts have been archived to permanent storage in the 5k subdirectory for subsequent analysis.« less

Authors:
;
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
909918
Report Number(s):
UCRL-TR-229427
TRN: US0704010
DOE Contract Number:
W-7405-ENG-48
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 73 NUCLEAR PHYSICS AND RADIATION PHYSICS; DIMENSIONS; MODIFICATIONS; PHYSICS; QUANTUM CHROMODYNAMICS; QUARKS; STORAGE; THERMALIZATION; THERMODYNAMICS; TRAJECTORIES; LATTICE FIELD THEORY

Citation Formats

Soltz, R, and Gupta, R. Lattice QCD Thermodynamics First 5000 Trajectories. United States: N. p., 2007. Web. doi:10.2172/909918.
Soltz, R, & Gupta, R. Lattice QCD Thermodynamics First 5000 Trajectories. United States. doi:10.2172/909918.
Soltz, R, and Gupta, R. Thu . "Lattice QCD Thermodynamics First 5000 Trajectories". United States. doi:10.2172/909918. https://www.osti.gov/servlets/purl/909918.
@article{osti_909918,
title = {Lattice QCD Thermodynamics First 5000 Trajectories},
author = {Soltz, R and Gupta, R},
abstractNote = {These results represent the first LQCD analysis for approximately 5000 trajectories with each of the p4rhmc and milc codes, with some of the lower temperature runs having fewer. Both runs were for lattice dimensions of 32{sup 3}x8. Some 32{sup 4} T=0 jobs were also run for p4rhmc. The p4 calculation was performed with v2.0 QMP{_}MPI.X (semi-optimized p4 code using qmp over mpi) and milc version of the su3 rhmc susc eos executable dated Mar 1, 2007 on ubgl in the /usr/gapps/hip/qcd/milc/bin subdirectory (svn revision 28). As with previous runs, calculations were performed along lines of constant physics, with the light quark masses 2-3 times their physics values and the strange quark mass set by m{sub ud} = 0.1m{sub s}. Job submissions were performed using a new subSet.pl job submission script that locates current jobs and submits additional jobs with the same beta value as pending. Note that after reaching a limit of about 35 jobs subsequent submissions are delayed and will not be submitted directly from that state. The job submission script was used to submit revised versions of the milc and p4rhmc csh scripts. Initial thermalized lattices for each code were also for milc (taken from the firstPhys runs), but the p4rhmc runs include thermalization. The only modifications for running on BG/L were to the directory names and the mT parameter which determines job durations (24 hrs on BG/L vs. 4 hrs on ubgl). All finite temperature jobs were submitted to the 512 node partitions, and all T=0 runs were submitted to 2048 node partitions. The set of runs was plagued by filesystem errors on lscratch1 and lscratcH{sub 2}. Many jobs had to be reset (deleting the most recent output file for milc and/or lattice for p4) and resubmitted. The analysis was performed with a new set of scripts that produced a more condensed output for scanning. All scans were verified with checksums, which have been retained in the output along with the line numbers. All lattices, log files, and job submission scripts have been archived to permanent storage in the 5k subdirectory for subsequent analysis.},
doi = {10.2172/909918},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Mar 15 00:00:00 EDT 2007},
month = {Thu Mar 15 00:00:00 EDT 2007}
}

Technical Report:

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  • This is a re-analysis of the Lattice QCD Thermodynamics p4rhcm new beta analysis (UCRL-TR-230742) with approximately 10k trajectories per beta point, rerun with thermalization cut at 1000, and a block size of 500. Some diagnostic text has been omitted to reduce the number of pages.
  • We apply methods developed by Lovelace, Lipatov, and Kirschner to evaluate the leading Regge trajectories {alpha}(t) with the quantum numbers of nonexotic quark-antiquark mesons at N{sub e} = {infinity} in the limit t {yields} {minus}{infinity} where renormalization group improved perturbation theory should be valid. We discuss the compatibility of nonlinear trajectories with narrow resonance approximations.
  • We apply methods developed by Lovelace, Lipatov, and Kirschner to evaluate the leading Regge trajectories {alpha}(t) with the quantum numbers of nonexotic quark-antiquark mesons at N{sub e} = {infinity} in the limit t {yields} {minus}{infinity} where renormalization group improved perturbation theory should be valid. We discuss the compatibility of nonlinear trajectories with narrow resonance approximations.
  • Nuclear physics entails the study of the properties and interactions of hadrons, such as the proton and neutron, and atomic nuclei and it is central to our understanding of our world at the smallest scales. The underlying basis for nuclear physics is provided by the Standard Model of particle physics which describes how matter interacts through the strong, electromagnetic and weak (electroweak) forces. This theory was developed in the 1970s and provides an extremely successful description of our world at the most fundamental level to which it has been probed. The Standard Model has been, and continues to be, subjectmore » to stringent tests at particle accelerators around the world, so far passing without blemish. However, at the relatively low energies that are relevant for nuclear physics, calculations involving the strong interaction, governed by the equations of Quantum Chromodynamics (QCD), are enormously challenging, and to date, the only systematic way to perform them is numerically, using a framework known as lattice QCD (LQCD). In this approach, one discretizes space-time and numerically solves the equations of QCD on a space-time lattice; for realistic calculations, this requires highly optimized algorithms and cutting-edge high performance computing (HPC) resources. Progress over the project period is discussed in detail in the following subsections« less
  • Trajectories of paramagnetic particles in regular infinite rectangular and rhombic lattices of parallel magnetized fibers have been calculated. The mathematical model for this analysis accounts for both the collective magnetic and the collective fluid effects of all the fibers in the lattice in the potential flow regime. The viscous force on the particles is taken to be the Stokes force, and diffusion and particle inertia are assumed to be negligible. The particle capture cross section for a fiber in a lattice is found to be significantly different from the isolated fiber cross section for closely packed fibers. However, they becomemore » equal as the filter porosity approaches unity. It is seen that channels form, allowing particles to pass through the filter. These channels persist for arbitrarily large porosity, but can be made as narrow as desired by increasing the ratio of magnetic to viscous forces.« less