ρ meson decay in 2 + 1 flavor lattice QCD.

We perform a lattice QCD study of the ρ meson decay from the Nf = 2 + 1 full QCD configurations generated with a renormalization group improved gauge action and a nonperturbatively O(a)-improved Wilson fermion action. The resonance parameters, the effective ρ → ππ coupling constant and the resonance mass, are estimated from the P-wave scattering phase shift for the isospin I = 1 two-pion system. The finite size formulas are employed to calculate the phase shift from the energy on the lattice. Our calculations are carried out at two quark masses, mπ = 410 MeV (mπ/mρ = 0.46) and mπ = 300 MeV (mπ/mρ = 0.35), on a 32³ x 64 (La = 2.9 fm) lattice at the lattice spacing a = 0.091 fm. We compare our results at these two quark masses with those given in the previous works using Nf = 2 full QCD configurations and the experiment. [ABSTRACT FROM AUTHOR]