On the mechanism of open-flavor strong decays

Open-flavor strong decays are mediated by $q\overline{q}$ pair production, which is known to occur dominantly with ${}_{}{}^3{}_{}{}^{}P_0^{}{}_{}{}^{}$ quantum numbers. The relation of the phenomenological ${}_{}{}^3{}_{}{}^{}P_0^{}{}_{}{}^{}$ model of these decays to "microscopic" QCD decay mechanisms has never been established clearly. In this paper we investigate $q\overline{q}$ meson decay amplitudes assuming pair production from the scalar confining interaction ($\mathrm{sKS}$) and from one gluon exchange (OGE). $\mathrm{sKS}$ pair production predicts decay amplitudes of approximately the correct magnitude and $\frac{D}{S}$ amplitude ratios in $b_1\to \omega \pi$ and $a_1\to \rho \pi$ which are close to experiment. The OGE decay amplitude is found to be subdominant in most cases, a notable exception being ${}_{}{}^3{}_{}{}^{}P_0^{}{}_{}{}^{}\to {}_{}{}^1{}_{}{}^{}S_0^{}{}_{}{}^{}+{}_{}{}^1{}_{}{}^{}S_0^{}{}_{}{}^{}$. The full $\mathrm{sKs}$ + OGE amplitudes differ significantly from ${}_{}{}^3{}_{}{}^{}P_0^{}{}_{}{}^{}$ model predictions in some channels and can be distinguished experimentally, for example, through an accurate comparison of the $\frac{D}{S}$ amplitude ratios in $b_1\to \omega \pi$ and $a_1\to \rho \pi$.