Radiative Corrections to the Photon + 1 Jet Rate at LEP

Abstract

We present the results of a calculation of the rate for the annihilation of an $e^{+}{e}^{-}$ pair into a jet containing an energetic photon and a single further jet at order $\alpha {\alpha }_s$. By comparing these results with the existing data on the photon + 1 jet rate from the ALEPH Collaboration, we make a first determination of the process independent quark-to-photon fragmentation function $D_{q\to \gamma }(z,{\mu }_F)$ at order $\alpha {\alpha }_s$. We also compare our prediction for the inclusive photon energy spectrum with the recent OPAL measurement.

Comments: 13 pages, LaTeX, 6 figures included; Discussion on resummation approaches and comparison to recent OPAL data on inclusive photon energy spectrum added; to appear in Phys.Lett.B