A Measurement of the Proton Structure Function $F_{\!2}(x,Q^2)$

TL;DR

This paper reports measurements of the proton structure function $F_2(x,Q^2)$ over a broad range of $Q^2$ and $x$, confirming its increase at low $x$ and analyzing the diffractive contribution using deep inelastic events with large rapidity gaps.

Contribution

First measurement of $F_2$ over this kinematic range with detailed analysis of its $Q^2$ and $x$ dependence and the diffractive component using HERA data.

Findings

$F_2$ increases significantly as $x$ decreases.

$Q^2$ dependence is approximately logarithmic.

Diffractive contribution to $F_2$ measured using rapidity gap events.

Abstract

A measurement of the proton structure function $F_{\!2}(x,Q^2)$ is reported for momentum transfer squared $Q^2$ between 4.5 $GeV^2$ and 1600 $GeV^2$ and for Bjorken $x$ between $1.8\cdot10^{-4}$ and 0.13 using data collected by the HERA experiment H1 in 1993. It is observed that $F_{\!2}$ increases significantly with decreasing $x$, confirming our previous measurement made with one tenth of the data available in this analysis. The $Q^2$ dependence is approximately logarithmic over the full kinematic range covered. The subsample of deep inelastic events with a large pseudo-rapidity gap in the hadronic energy flow close to the proton remnant is used to measure the "diffractive" contribution to $F_{\!2}$.