TheηNNcoupling constant

Abstract

We derive the light cone QCD sum rule for the $\ensuremath{\eta}\mathrm{NN}$ coupling constant ${g}_{\ensuremath{\eta}\mathrm{NN}}.$ The contribution from the excited states and the continuum is subtracted cleanly through the double Borel transform with respect to the two external momenta, ${p}_{1}^{2}{,p}_{2}^{2}=(p\ensuremath{-}{q)}^{2}.$ Our result is ${\ensuremath{\alpha}}_{\ensuremath{\eta}\mathrm{NN}}=(0.3\ifmmode\pm\else\textpm\fi{}0.15),$ which favors small values used in the literature.