Portal de Periódicos da CAPES

π K scattering in full QCD with domain-wall valence quarks

2006; American Physical Society; Volume: 74; Issue: 11 Linguagem: Inglês

10.1103/physrevd.74.114503

1550-7998

Silas R. Beane, Paulo F. Bedaque, Thomas Luu, Kostas Orginos, Elisabetta Pallante, A. Parreño, Martin J. Savage,

High-Energy Particle Collisions Research

We calculate the ${\ensuremath{\pi}}^{+}{K}^{+}$ scattering length in fully-dynamical lattice QCD with domain-wall valence quarks on MILC lattices with rooted staggered sea-quarks at a lattice spacing of $b=0.125\text{ }\text{ }\mathrm{fm}$, lattice spatial size of $L=2.5\text{ }\text{ }\mathrm{fm}$ and at pion masses of ${m}_{\ensuremath{\pi}}\ensuremath{\sim}290$, 350, 490 and 600 MeV. The lattice data, analyzed at next-to-leading order in chiral perturbation theory, allows an extraction of the full $\ensuremath{\pi}K$ scattering amplitude at threshold. Extrapolating to the physical point gives ${m}_{\ensuremath{\pi}}{a}_{3/2}=\ensuremath{-}0.0574\ifmmode\pm\else\textpm\fi{}{0.0016}_{\ensuremath{-}0.0058}^{+0.0024}$ and ${m}_{\ensuremath{\pi}}{a}_{1/2}=0.1725\ifmmode\pm\else\textpm\fi{}{0.0017}_{\ensuremath{-}0.0156}^{+0.0023}$ for the $I=3/2$ and $I=1/2$ scattering lengths, respectively, where the first error is statistical and the second error is an estimate of the systematic due to truncation of the chiral expansion.