On determination of the large-$\frac{1}{x}$ gluon distribution at HERA

Abstract

We discuss corrections to the Leading-Log$Q^2$ relationships between the gluon density $g(x,Q^2)$ and $F_L(x,Q^2),\partial F_T(x,Q^2)/\partial \log Q^2$ in the HERA range of large $\frac{1}{x}$. We find that the above quantities probe the gluon density $g(x,Q_{T,L}^2)$ at $Q_{T,L}^2=C_{T,L}{Q}^2$, with the $Q^2$-rescaling factors $C_T\approx 2.2$ and $C_L\approx 0.42$. The possibility of treating charm as an active flavour is critically re-examined.

Comments: 12 pages, 4 figures upon the request from kph154@zam001.zam.kfa-juelich.de, Jülich preprint KFA-IKP(TH)-1994-12. Some misprints and ordering of references corrected