Reaction rate, weak corrections, and background ine+e−→π0γ,ηγ

Abstract

The ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}\ensuremath{\gamma}$,$\ensuremath{\eta}\ensuremath{\gamma}$ cross sections at high energies are computed on the basis of resonance-pole and quark-loop approximations. A sizable difference is found between the results of these two models; this makes the measurement one of importance especially for detection of charmed, and heavier, quarks. The effects of beam polarization are included, as are the weak (neutral-current) corrections. The weak corrections are, in most weak-interaction models, relatively small. The $3\ensuremath{\gamma}$ background is also computed including the effects of beam polarization. It is large and there does not seem to be an easy way of using beam-polarization effects to suppress it.