Eur. Phys. J. C 18, 593-599
DOI: 10.1007/s100520100552

Photon structure functions beyond the SUSY threshold

D.A. Ross and L.J. Weston

Department of Physics and Astronomy, University of Southampton, Southampton S017 1BJ, UK

(Received: 25 August 2000 / Revised version: 1 November 2000 / Published online: 21 December 2000 -© Springer-Verlag 2000)

Abstract
We evolve virtual photon parton densities up to the SUSY threshold and higher using coupled inhomogeneous DGLAP differential equations. Reliable input parameterizations were available from the c-quark threshold. Limited P² (target photon virtuality) dependence is observed. The difference to the photon structure function is shown to be significant with the introduction of SUSY dependent splitting functions. A negligible difference is observed by letting the gluino mass enter after the squark mass. An effort is made to include the squark threshold effect in such a way that both the renormalization group equations are satisfied and the perturbative calculation is reproduced.

© Società Italiana di Fisica, Springer-Verlag 2001