Elastic I=3/2 p-wave nucleon-pion scattering amplitude and the Δ(1232) resonance from Nf=2+1 lattice QCD

摘要

We present the first direct determination of meson-baryon resonance parameters from a scattering amplitude calculated using lattice QCD. In particular, we calculate the elastic I=3/2, p-wave nucleon-pion amplitude on a single ensemble of Nf=2+1 Wilson-clover fermions with mπ=280??MeV and mK=460??MeV. At these quark masses, the Δ(1232) resonance pole is found close to the N?π threshold and a Breit-Wigner fit to the amplitude gives gΔNπBW=19.0(4.7) in agreement with phenomenological determinations.