Measurement of the longitudinal structure function of the proton, FL

TL;DR

This paper reports the first direct measurements of the proton's longitudinal structure function, FL, and also extracts F2 at high y without assumptions, providing new insights into proton structure and gluon density.

Contribution

It presents the first direct measurements of FL and a novel extraction of F2 at high y without prior assumptions, advancing understanding of proton structure.

Findings

First direct measurement of FL

Extraction of F2 at high y without assumptions

Enhanced understanding of gluon density in the proton

Abstract

The ZEUS and H1 collaborations have made the first direct measurements of the longitudinal proton structure function, FL, which is strongly correlated to the gluon density in the proton. The ZEUS collaboration have also extracted the structure function, F2, which, for the first time, has been done so at high y without any assumptions about FL.