Charge asymmetry ine+e−→γ+hadrons: New tests of the quark-parton model and fractional charge

Abstract

We consider the process $e^{+}{e}^{-}\to \gamma +h+X$, where $h$ is a hadron and $\gamma$ is a hard photon, and show how it can be used to test the quark-parton model. Detailed formulas are given for the cross sections, which in the quark-parton model are products of cross sections for $e^{+}{e}^{-}\to \gamma \mu \overline{\mu }$ and quark breakup functions. We focus on the asymmetry between $h$ and $\overline{h}$ production, and display sum rules and ratio tests which measure the quark charge, the quark Compton amplitude, and the large-$x$ behavior of the quark breakup function. The asymmetry is calculated for the muon case, and is about 100% for the forward direction.