Renormalization scale-fixing for complex scattering amplitudes
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: email@example.com
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