Inclusive Deep Inelastic Scattering at High Q2 with Longitudinally Polarised Lepton Beams at HERA

TL;DR

This paper reports precise measurements of deep inelastic scattering cross sections at HERA with polarized lepton beams, providing new insights into proton structure functions and testing the Standard Model at high momentum transfers.

Contribution

It presents the first measurement of the neutral current parity violating structure function F_2^gammaZ and combines polarized data with previous unpolarized data to refine proton structure functions.

Findings

Measured differential cross sections over a wide Q2 and x range.

First measurement of the structure function F_2^gammaZ.

Polarization dependence of charged current cross section observed.

Abstract

Inclusive e\pmp single and double differential cross sections for neutral and charged current deep inelastic scattering processes are measured with the H1 detector at HERA. The data were taken at a centre-of-mass energy of \surds = 319GeV with a total integrated luminosity of 333.7 pb-1 shared between two lepton beam charges and two longitudinal lepton polarisation modes. The differential cross sections are measured in the range of negative fourmomentum transfer squared, Q2, between 60 and 50 000GeV2, and Bjorken x between 0.0008 and 0.65. The measurements are combined with earlier published unpolarised H1 data to improve statistical precision and used to determine the structure function xF_3^gammaZ. A measurement of the neutral current parity violating structure function F_2^gammaZ is presented for the first time. The polarisation dependence of the charged current total cross section is also measured. The new measurements are well described by a next-to-leading order QCD fit based on all published H1 inclusive cross section data which are used to extract the parton distribution functions of the proton.