Sigma Signal for Hybrid Baryon Decay

Abstract

We develop an ansatze of the sigma enhancement of the I=0, L=0 $π$-$π$ scattering amplitude as arising from a low-energy glueball pole. Using this picture we estimate the $π^0π^0$ to $π^0$ branching ratio for the decays of the Roper resonance, which we previously found to be a hybrid in our QCD sum rule calculation. We find that the sigma decay might be a good signal for gluonic components of hadrons.