I=2 Pion Scattering Length with the Wilson Fermion

Abstract

The calculation of the I=2 pion scattering length in quenched lattice QCD is revisited. The calculation is carried out with the Wilson fermion action employing Lüscher's finite size scaling method at ${\hat{I}}^2=5.9$, 6.1, and 6.3 corresponding to the range of lattice spacing $a\simeq 0.12-0.07$ fm. We obtain in the continuum limit $a_0{m}_{\ddot{I}}€=-0.0410(69)$, which is consistent with the prediction of chiral perturbation theory $a_0{m}_{\ddot{I}}€=-0.0444(10)$.

LaTeX, 14 pages, 5 eps figures, uses revtex and epsfig