English

Measurement of the Proton Structure Function F_L at Low x

High Energy Physics - Experiment 2012-08-27 v2

Abstract

A first measurement is reported of the longitudinal proton structure function F_L(x,Q^2) at the ep collider HERA. It is based on inclusive deep inelastic e^+p scattering cross section measurements with a positron beam energy of 27.5 GeV and proton beam energies of 920, 575 and 460 GeV. Employing the energy dependence of the cross section, F_L is measured in a range of squared four-momentum transfers 12 < Q^2 < 90 GeV^2 and low Bjorken x 0.00024 < x < 0.0036. The F_L values agree with higher order QCD calculations based on parton densities obtained using cross section data previously measured at HERA.

Keywords

Cite

@article{arxiv.0805.2809,
  title  = {Measurement of the Proton Structure Function F_L at Low x},
  author = {H1 Collaboration},
  journal= {arXiv preprint arXiv:0805.2809},
  year   = {2012}
}

Comments

16 pages, 6 figures, version accepted for publication in PLB, minor text changes