6533b7d3fe1ef96bd1260b79
RESEARCH PRODUCT
Low-energy couplings of QCD from current correlators near the chiral limit
Mikko LaineLeonardo GiustiPilar HernándezPeter WeiszHartmut Wittigsubject
QuarkNuclear and High Energy PhysicsChiral perturbation theoryCurrent (mathematics)High Energy Physics::LatticeFOS: Physical sciencesQuenched approximationStatistical fluctuationsDirac operatorsymbols.namesakechiral Lagrangianslattice QCDHigh Energy Physics - Phenomenology (hep-ph)High Energy Physics - Latticelattice gauge field theoriesPhysicsQuantum chromodynamicsHigh Energy Physics - Lattice (hep-lat)FísicaFermionQCDFIS/02 - FISICA TEORICA MODELLI E METODI MATEMATICIHigh Energy Physics - PhenomenologyLattice gauge theoryQuantum electrodynamicssymbolsdescription
We investigate a new numerical procedure to compute fermionic correlation functions at very small quark masses. Large statistical fluctuations, due to the presence of local ``bumps'' in the wave functions associated with the low-lying eigenmodes of the Dirac operator, are reduced by an exact low-mode averaging. To demonstrate the feasibility of the technique, we compute the two-point correlator of the left-handed vector current with Neuberger fermions in the quenched approximation, for lattices with a linear extent of L~1.5 fm, a lattice spacing a~0.09 fm, and quark masses down to the epsilon-regime. By matching the results with the corresponding (quenched) chiral perturbation theory expressions, an estimate of (quenched) low-energy constants can be obtained. We find agreement between the quenched values of F extrapolated from the p-regime and extracted in the epsilon-regime.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2004-02-03 |