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Chiral symmetry breaking in QCD with two light flavors
Georg P Engel1, Leonardo Giusti1, Stefano Lottini2
1Dipartimento di Fisica, Università di Milano-Bicocca, and INFN, Sezione di Milano-Bicocca, Piazza della Scienza 3, I-20126 Milano, Italy.
Physical Review Letters
|April 4, 2015
Summary
Spontaneous chiral symmetry breaking in Quantum Chromodynamics (QCD) is confirmed by low-mode condensation of the Dirac operator. This rate aligns with the Gell-Mann-Oakes-Renner relation, validating lattice QCD simulations.
Area of Science:
- * Theoretical Physics
- * Quantum Chromodynamics (QCD)
- * Hadron Spectroscopy
Background:
- * Spontaneous chiral symmetry breaking is a key feature of QCD.
- * This phenomenon is associated with the condensation of low-lying Dirac operator modes.
- * The rate of condensation is theoretically linked to meson properties.
Purpose of the Study:
- * To compute the spectral density of the Dirac operator and related meson properties.
- * To investigate the condensation of low quark modes in lattice QCD.
- * To verify the Banks-Casher mechanism and Gell-Mann-Oakes-Renner relation.
Main Methods:
- * Numerical simulations of lattice QCD using two light degenerate Wilson quarks.
- * Utilized CLS group lattices at lattice spacings of 0.05-0.08 fm.
- * Extrapolated results to the chiral and continuum limits for pseudoscalar meson masses down to 190 MeV.
Main Results:
- * Observed condensation of low quark modes in the continuum, consistent with the Banks-Casher mechanism.
- * The rate of condensation agrees with the Gell-Mann-Oakes-Renner relation.
- * Calculated renormalization-group-invariant ratios: [Σ(RGI)](1/3)/F=2.77(2)(4) and Λ(M̅S)/F=3.6(2).
Conclusions:
- * Lattice QCD simulations confirm spontaneous chiral symmetry breaking via low-mode condensation.
- * The findings support fundamental QCD relations like Banks-Casher and Gell-Mann-Oakes-Renner.
- * Derived values for key QCD condensates and constants, providing precise benchmarks.
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