Isolated and non-isolated photon rates at LEP
Abstract
Description
We present the results of the calculation of the `photon' +~1 jet rate at ${\cal O}(αα_{s})$ for LEP energies. By comparing these results with the data from the ALEPH Collaboration we make a next-to-leading order determination of the quark-to-photon fragmentation function $D_{q\to γ}(z,μ_{F})$ at ${\cal O}(αα_{s})$. The predictions obtained using this fragmentation function for the isolated rate, defined as the `photon' +~1 jet rate for $z>0.95$, are found in good agreement with the ALEPH data. The next-to-leading order corrections are moderate demonstrating the perturbative stability of this particular isolated photon definition. We have also computed the inclusive photon energy distribution and found good agreement with the OPAL data.
7 pages, LaTeX, 4 Postscript figures included, Talk presented at the Zeuthen Workshop on Elementary Particle Theory ``Loops and Legs in Gauge Theories" Rheinsberg, Germany, April 19-24,1998
7 pages, LaTeX, 4 Postscript figures included, Talk presented at the Zeuthen Workshop on Elementary Particle Theory ``Loops and Legs in Gauge Theories" Rheinsberg, Germany, April 19-24,1998