I=2 pion scattering length with the Wilson fermion

Abstract

The calculation of the 1=2 pion scattering length in quenched lattice QCD is reexamined. The calculation is carried out with the Wilson fermion action employing Lüscher's finite size scaling method at β=5.9, 6.1, and 6.3 corresponding to the range of lattice spacing a∼0.12- 0.07 fm. We obtain in the continuum limit a0/ m π= - 2.09(35) 1/GeV2, which is consistent with the prediction of chiral perturbation theory a 0/mπ= - 2.265(51)1/GeV2. © 2002 The American Physical Society.