Zusammenfassung
We carry out the first complete calculation of kinematic power corrections similar to t/Q(2) and similar to m(2)/Q(2) to several key observables in deeply virtual Compton scattering. The issue of convention dependence of the leading twist approximation is discussed in detail. In addition, we work out representations for the higher twist corrections in terms of double distributions, Mellin-Barnes ...
Zusammenfassung
We carry out the first complete calculation of kinematic power corrections similar to t/Q(2) and similar to m(2)/Q(2) to several key observables in deeply virtual Compton scattering. The issue of convention dependence of the leading twist approximation is discussed in detail. In addition, we work out representations for the higher twist corrections in terms of double distributions, Mellin-Barnes integrals and also within a dissipative framework. This study removes an important source of uncertainties in the QCD predictions for intermediate photon virtualities Q2 similar to 1-5 GeV2 that are accessible in the existing and planned experiments. In particular the finite-t corrections are significant and must be taken into account in the data analysis.
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