Pinning down the Glue in the Proton

A. D. Martin; R. G. Roberts; W. J. Stirling

doi:10.1016/0370-2693(95)00646-3

paper

Pinning down the Glue in the Proton

arXiv:hep-ph/9502336 · doi:10.1016/0370-2693(95)00646-3

Abstract

The latest measurements of $F_{2}$ at HERA allow for a {\it combination} of gluon and sea quark distributions at small $x$ that is significantly different from those of existing parton sets. We perform a new global fit to deep-inelastic and related data. We find a gluon distribution which is larger for $x \lapproxeq 0.01$, and smaller for $x \sim 0.1$ , and a flatter input sea quark distribution than those obtained in our most recent global analysis. The new fit also gives $α_{s} (M_{Z}^{2}) = 0.114$ . We study other experimental information available for the gluon including, in particular, the constraints coming from fixed-target and collider prompt $γ$ production data.

8 pages, LATEX, 6 figs available as .uu file