2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/179664We determine the mass and decay constant of the $a_1$ meson using Monte Carlo simulation of lattice QCD. We find $M_{a_1} = 1250 \pm 80$ MeV and $f_{a_1} = 0.30 \pm 0.03 ~({\rm GeV})^2$, in good agreement with experiment.9 page uu-encoded compressed postscript file. version appearing in Phys. Rev. Lett. 74 (1995) 4596High Energy Physics - PhenomenologyHigh Energy Physics - Latticetext