Abstract
We argue that the use of the universal unintegrated gluon distribution and the [Formula presented] (or high energy) factorization theorem provides the natural framework for describing observables at small [Formula presented] We introduce a coupled pair of evolution equations for the unintegrated gluon distribution and the sea quark distribution which incorporate both the resummed leading [Formula presented] BFKL contributions and the resummed leading [Formula presented] GLAP contributions. We solve these unified equations in the perturbative QCD domain using simple parametric forms of the nonperturbative part of the integrated distributions. With only two (physically motivated) input parameters we find that this [Formula presented] factorization approach gives an excellent description of the measurements of [Formula presented] at DESY HERA. In this way the unified evolution equations allow us to determine the gluon and sea quark distributions and, moreover, to see the [Formula presented] domain where the resummed [Formula presented] effects become significant. We use [Formula presented] factorization to predict the longitudinal structure function [Formula presented] and the charm component of [Formula presented]
Original language | English (US) |
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Pages (from-to) | 3991-4006 |
Number of pages | 16 |
Journal | Physical Review D - Particles, Fields, Gravitation and Cosmology |
Volume | 56 |
Issue number | 7 |
DOIs | |
State | Published - 1997 |
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics
- Physics and Astronomy (miscellaneous)