https://doi.org/10.1140/epjc/s2006-02520-0
Theoretical Physics
Renormalization scale-fixing for complex scattering amplitudes
1
Stanford Linear Accelerator Center, Stanford University, Stanford, California, 94309, USA
2
Depto. Física Teórica I, Fac. Cc. Físicas, Universidad Complutense de Madrid, 28040, Madrid, Spain
* e-mail: sjbth@slac.stanford.edu
Received:
21
December
2005
Revised:
9
February
2006
Published online:
12
April
2006
We show how to fix the renormalization scale for hard-scattering exclusive processes such as deeply virtual meson electroproduction by applying the BLM prescription to the imaginary part of the scattering amplitude and employing a fixed-t dispersion relation to obtain the scale-fixed real part. In this way, we resolve the ambiguity in BLM renormalization scale-setting for complex scattering amplitudes. We illustrate this by computing the H generalized parton distribution at leading twist in an analytic quark-diquark model for the parton-proton scattering amplitude that can incorporate Regge exchange contributions characteristic of the deep inelastic structure functions.
© Springer-Verlag, 2006
