How to measure the intercept of the BFKL pomeron at HERA

Abstract

Determination of the intercept of the BFKL pomeron is one of the pressing issues in the high energy physics. Earlier we have shown that, at the dipole size $r=r_{\Delta }=(0.1-0.2)$f, the dipole cross section $\sigma (x,r)$ which is a solution of the generalized BFKL equation, exhibits a precocious asymptotic behavior $\sigma (x,r)\propto {\left(\frac{1}{x}\right)}^{{\Delta }_{\text{Pom}}}$. In this paper we discuss how measuring $F_L(x,Q^2)$ and $\partial F_T(x,Q^2)/\partial \log Q^2$ at $Q^2=(10-40)$GeV${}^2$ and $Q^2=(2-10)$GeV${}^2$, respectively, one can probe $\sigma (x,r_{\Delta })$ and directly determine the intercept ${\Delta }_{\text{Pom}}$ of the BFKL pomeron in the HERA experiments.

Comments: 10 pages, 2 figures upon the request from kph154@zam001.zam.kfa-juelich.de, Juelich preprint KFA-IKP(Th)-1994-10, 28 February 1994