ISOLATED PROMPT PHOTON PRODUCTION IN HADRONIC FINAL-STATES OF E(-) ANNIHILATION()E()

We provide complete analytic expressions for the isolated prompt photo n production cross section in e(+)e(-) annihilation reactions through one-loop order in quantum chromodynamics (QCD) perturbation theory. Fu nctional dependences on the isolation cone size delta and isolation en ergy parameter epsilon are derived. The energy dependence as well as t he full angular dependence pf the cross section on theta(gamma) are di splayed, where theta(gamma) specifies the direction of the photon with respect to the e(+)e(-) collision axis. We point out that conventiona l perturbative QCD factorization breaks down for isolated photon produ ction in e(+)e(-) annihilation reactions in a specific region of phase space. We discuss the implications of this breakdown for the extracti on of fragmentation functions from e(+)e(-) annihilation data and for computations of prompt photon production in hadron-hadron reactions.