Hadronic Coupling Constants in Lattice QCD

Abstract

We calculate the hadronic coupling constants $g_{NN\pi}$ and $g_{\rho\pi\pi}$ in QCD, including dynamical quarks in the framework of staggered fermions in the lattice approach. For the nucleon--pion coupling we obtain $g_{NN\pi} = 13.8 \pm 5.8$, to be compared with the experimental value $13.13 \pm 0.07$. The $\rho\pi\pi$ coupling has been analysed for two different sets of operators with the averaged result $g_{\rho\pi\pi} = 4.2 \pm 1.9$ which is to be compared with the experimental value $6.06 \pm 0.01$.