https://doi.org/10.1140/epjc/s10052-013-2534-3
Regular Article - Theoretical Physics
Treatment of the infrared contribution: NLO QED evolution as a pedagogic example
1
Institute for Particle Physics Phenomenology, University of Durham, DH1 3LE, Durham, UK
2
Instituto de Física, Universidade de São Paulo, C.P. 66318, 05315-970, São Paulo, Brazil
3
Petersburg Nuclear Physics Institute, NRC Kurchatov Institute, Gatchina, 188300, St. Petersburg, Russia
* e-mail: ego@if.usp.br
Received:
1
July
2013
Published online:
27
August
2013
We show that the conventional prescription used for DGLAP parton evolution at NLO has an inconsistent treatment of the contribution from the infrared (IR) region. We illustrate the problem by studying the simple example of QED evolution, treating the electron and photon as partons. The deficiency is not present in a physical approach which removes the IR divergency and allows calculation in the normal 4-dimensional space.
© Springer-Verlag Berlin Heidelberg and Società Italiana di Fisica, 2013
