Topological susceptibility with the improved Asqtad action

Claude Bernard, Thomas DeGrand, Anna Hasenfratz, Carleton DeTar, James Osborn, Steven Gottlieb, Eric Gregory, William D Toussaint, Alistair Hart, Urs M. Heller, James Hetrick, Robert L. Sugar

Research output: Contribution to journalArticle

35 Citations (Scopus)

Abstract

Chiral perturbation theory predicts that in quantum chromodynamics light dynamical quarks suppress the topological (instanton) susceptibility. We investigate this suppression through direct numerical simulation using the Asqtad improved lattice fermion action. This action holds promise for carrying out nonperturbative simulations over a range of quark masses for which chiral perturbation theory is expected to converge. To test the effectiveness of the action in capturing instanton physics, we measure the topological susceptibility as a function of quark masses with 2 + 1 dynamical flavors. Our results, when extrapolated to zero lattice spacing, are consistent with predictions of leading order chiral perturbation theory. Included in' our study is a comparison of three methods for analyzing the topological susceptibility: (1) the Boulder hypercubic blocking technique with the Boulder topological charge operator, (2) the more traditional Wilson cooling method with the twisted plaquette topological charge operator and (3) the improved cooling method of de Forcrand, Perez, and Stamatescu and their improved topological charge operator. We show in one comparison at nonzero lattice spacing that the largest difference between methods (1) and (2) can be attributed to the operator, rather than the smoothing method.

Original languageEnglish (US)
Article number114501
JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
Volume68
Issue number11
DOIs
StatePublished - 2003

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magnetic permeability
operators
perturbation theory
quarks
instantons
spacing
cooling
direct numerical simulation
smoothing
quantum chromodynamics
fermions
retarding
physics
predictions
simulation

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

Cite this

Bernard, C., DeGrand, T., Hasenfratz, A., DeTar, C., Osborn, J., Gottlieb, S., ... Sugar, R. L. (2003). Topological susceptibility with the improved Asqtad action. Physical Review D - Particles, Fields, Gravitation and Cosmology, 68(11), [114501]. https://doi.org/10.1103/PhysRevD.68.114501

Topological susceptibility with the improved Asqtad action. / Bernard, Claude; DeGrand, Thomas; Hasenfratz, Anna; DeTar, Carleton; Osborn, James; Gottlieb, Steven; Gregory, Eric; Toussaint, William D; Hart, Alistair; Heller, Urs M.; Hetrick, James; Sugar, Robert L.

In: Physical Review D - Particles, Fields, Gravitation and Cosmology, Vol. 68, No. 11, 114501, 2003.

Research output: Contribution to journalArticle

Bernard, C, DeGrand, T, Hasenfratz, A, DeTar, C, Osborn, J, Gottlieb, S, Gregory, E, Toussaint, WD, Hart, A, Heller, UM, Hetrick, J & Sugar, RL 2003, 'Topological susceptibility with the improved Asqtad action', Physical Review D - Particles, Fields, Gravitation and Cosmology, vol. 68, no. 11, 114501. https://doi.org/10.1103/PhysRevD.68.114501
Bernard, Claude ; DeGrand, Thomas ; Hasenfratz, Anna ; DeTar, Carleton ; Osborn, James ; Gottlieb, Steven ; Gregory, Eric ; Toussaint, William D ; Hart, Alistair ; Heller, Urs M. ; Hetrick, James ; Sugar, Robert L. / Topological susceptibility with the improved Asqtad action. In: Physical Review D - Particles, Fields, Gravitation and Cosmology. 2003 ; Vol. 68, No. 11.
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