Light meson spectrum with $N_f=2+1$ dynamical overlap fermions

Abstract

We report on a numerical simulation with 2+1 dynamical flavors of overlap fermions. We calculate pseudo-scalar masses and decay constants on a 16 3 × 48 × (0.11 fm) 4 lattice at five different up and down quark masses and two strange quark masses. The lightest pion mass corresponds to ≈ 310 MeV. We also study the validity of the chiral perturbation theory using the results of the numerical simulation with two dynamical flavors and conclude that the one-loop formulae cannot be directly applied in the strange quark mass region. We therefore extrapolate our 2+1-flavor results to the chiral limit by fitting the data to the two-loop formulae of the chiral perturbation theory.

Physics results from dynamical overlap fermion simulations

“…We are currently extending the NNLO analysis to the partially quenched data in two-flavor QCD and to the 2+1-flavor QCD data [4].…”

“…The relation between the θ and Q vacuums can be extended to any physical quantities. For example, for a (CP-even) two-point function, one can express it in a given topological charge Q in terms of its counterpart in the θ (=0) vacuum G(0) and its second and fourth derivatives G (2) (0) and G (4) (0) as [20,21]…”

“…The present talk discusses about the physics applications from the project in some detail. For individual contributions, see their own write-ups [2,3,4,5,6,7,8].…”

Applications of chiral perturbation theory to lattice QCD

“…88 For an early attempt to fit N f = 2 + 1 full-QCD overlap results to O(p 6 ) ChPT including two-loop nonanalytic terms, see Ref. [91].…”

Topological susceptibilty in (2+1)-flavor lattice QCD with overlap fermion

“…In order to convert Σ to that in the MS scheme, we calculate the renormalization factor Z MS m (2 GeV) using the non-perturbative renormalization technique through the RI/MOM scheme. Our result is Z MS m ({mathrm2 GeV ) = 0.833(8) [14]. With a −1 = 1833(12) MeV determined with r 0 = 0.49 fm [12], the value of Σ is transcribed to…”