Combination and QCD analysis of charm and beauty production cross section measurements in deep inelastic $ep$ scattering at HERA

Oleksandr Zenaiev

doi:10.22323/1.340.0449

Abstract

Measurements of open charm and beauty production cross sections in deep inelastic $ep$ scattering at HERA from the H1 and ZEUS Collaborations are combined and reduced cross sections are obtained. The combination method accounts for the correlations of the statistical and systematic uncertainties among the different datasets. Perturbative QCD calculations are compared to the combined data. A next-to-leading order QCD analysis is performed using these data together with the combined inclusive deep inelastic scattering cross sections from HERA. The running charm- and beauty-quark masses are determined.

Highlights

Measurements of open charm and beauty production in deep inelastic electron–proton scattering (DIS) at HERA provide important input for stringent tests of QCD. This analysis [1] is an extension of the previous H1 and ZEUS combination [2] of charm measurements in DIS [3, 4, 5, 6, 7, 8, 9, 10] with new charm and beauty data [11, 12, 13, 14, 15, 3]
The reduced cross sections are determined at common points from the visible cross sections, defined as the D, μ, e- or jet-production cross sections in a particular kinematic range, using theoretical predictions obtained with the HVQDIS programme [17] and extended with fragmentation models to provide hadron level cross sections as described elsewhere [2, 18]
The combined beauty and charm data are included in a QCD analysis at NLO, performed using XFITTER [21], together with the combined HERA inclusive DIS data [16]

Summary

Introduction

Measurements of open charm and beauty production in deep inelastic electron–proton scattering (DIS) at HERA provide important input for stringent tests of QCD. This analysis [1] is an extension of the previous H1 and ZEUS combination [2] of charm measurements in DIS [3, 4, 5, 6, 7, 8, 9, 10] with new charm and beauty data [11, 12, 13, 14, 15, 3]. The reduced charm, σrcecd , and beauty, σrbebd , cross sections are combined to create one consistent set of charm and beauty cross sections in the kinematic range of photon virtuality 2.5 ≤ Q2 ≤ 2000 GeV2 and Bjorken scaling variable 3 × 10−5 ≤ xBj ≤ 5 × 10−2: σrQedQ

Results

Conclusion