Convergence of the chiral expansion in two-flavor lattice QCD

Collaborations
Jun, 2008
10 pages
Published in:
  • Phys.Rev.Lett. 101 (2008) 202004
e-Print:
Report number:
  • KEK-CP-212,
  • NTUTH-08-505A,
  • UT-559,
  • YITP-08-38,
  • KEK-CP-212,NTUTH-08-505A,UT-559,YITP-08-38

Citations per year

200420092014201920230510152025
Abstract: (arXiv)
We test the convergence property of the chiral perturbation theory (ChPT) using a lattice QCD calculation of pion mass and decay constant with two dynamical quark flavors. The lattice calculation is performed using the overlap fermion formulation, which realizes exact chiral symmetry at finite lattice spacing. By comparing various expansion prescriptions, we find that the chiral expansion is well saturated at the next-to-leading order (NLO) for pions lighter than \sim450 MeV. Better convergence behavior is found in particular for a resummed expansion parameter ξ\xi, with which the lattice data in the pion mass region 290\sim750 MeV can be fitted well with the next-to-next-to-leading order (NNLO) formulae. We obtain the results in two-flavor QCD for the low energy constants lˉ3\bar{l}_3 and lˉ4\bar{l}_4 as well as the pion decay constant, the chiral condensate, and the average up and down quark mass.
Note:
  • 4pages, the version accepted in Phys. Rev. Lett
  • 12.38.Gc
  • 11.30.Rd
  • 12.39.Fe
  • 11.15.Ha
  • quantum chromodynamics
  • lattice field theory
  • flavor: 2
  • perturbation theory: chiral
  • pi: mass
  • pi: decay constant