A Direct Determination of the Gluon Density in the Proton at Low x

TL;DR

This paper presents a direct measurement of the gluon density in the proton at low x using multi-jet events from boson-gluon fusion, revealing a significant increase in gluon density as x decreases.

Contribution

It provides the first direct determination of the gluon density in a previously inaccessible low-x region using deep-inelastic scattering data.

Findings

Gluon density increases significantly as x decreases.

Measurement covers fractional momentum range $1.9 imes 10^{-3}$ to 0.18.

Results enhance understanding of proton structure at low x.

Abstract

A leading order determination of the gluon density in the proton has been performed in the fractional momentum range $1.9 \cdot 10^{-3} < x_{g/p} < 0.18$ by measuring multi-jet events from boson-gluon fusion in deep-inelastic scattering with the H1 detector at the electron-proton collider HERA. This direct determination of the gluon density was performed in a kinematic region previously not accessible. The data show a considerable increase of the gluon density with decreasing fractional momenta of the gluons.