Measurement of Inclusive ep Cross Sections at High Q2 at sqrt(s) = 225 and 252 GeV and of the Longitudinal Proton Structure Function FL at HERA

TL;DR

This paper reports measurements of inclusive deep inelastic scattering cross sections at high Q^2 at HERA, and uses these to extract the longitudinal proton structure function FL across a broad kinematic range.

Contribution

It provides new measurements at lower proton beam energies and combines them with existing data to determine the proton structure function FL.

Findings

Measured cross sections at two different proton energies.

Extracted the longitudinal structure function FL over a wide Q^2 range.

Enhanced understanding of proton structure at high energies.

Abstract

Inclusive ep double differential cross sections for neutral current deep inelastic scattering are measured with the H1 detector at HERA. The data were taken with a lepton beam energy of 27.6 GeV and two proton beam energies of Ep = 460 and 575 GeV corresponding to centre-of-mass energies of 225 and 252 GeV, respectively. The measurements cover the region of 6.5 *10^{-4}<=x<= 0.65 for 35<=Q^2<=800 GeV^2 up to y = 0.85. The measurements are used together with previously published H1 data at Ep = 920 GeV and lower Q2 data at Ep = 460, 575 and 920 GeV to extract the longitudinal proton structure function FL in the region 1.5<=Q^2 <=800 GeV^2.