On the possibility of measuring $F_L(x,Q^2)$ at HERA using radiative events

Abstract

It is shown that a significant measurement of the longitudinal structure function $F_L(x,Q^2)$ can be performed at HERA, for $Q^2=2Ge{V}^2$ and $Q^2=5Ge{V}^2$ and for x around $10^{-4}$, using radiative events with hard photon emission collinear to the incident lepton beam, under the present running conditions and with an integrated luminosity of 10 $p{b}^{-1}$. The influence of experimental conditions is discussed.

Comments: 12 pages (6 figures)