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

Measurements of open charm production cross sections in deep-inelastic ep scattering at HERA from the H1 and ZEUS Collaborations are combined. Reduced cross sections sigma(c (c) over bar)(red) for charm production are obtained in the kinematic range of photon virtuality 2.5 LT = Q(2) LT = 2000 GeV2 and Bjorken scaling variable 3 . 10(-5) LT = x LT = 5 . 10(-2). The combination method accounts for the correlations of the systematic uncertainties among the different data sets. The combined charm data together with the combined inclusive deep-inelastic scattering cross sections from HERA are used as input for a detailed NLO QCD analysis to study the influence of different heavy flavour schemes on the parton distribution functions. The optimal values of the charm mass as a parameter in these different schemes are obtained. The implications on the NLO predictions for W-+/- and Z production cross sections at the LHC are investigated. Using the fixed flavour number scheme, the running mass of the charm quark is determined

Measurement of beauty photoproduction near threshold using di-electron events with the H1 detector at HERA

The cross section for ep -> eb (b) over barX in photoproduction is measured with the H1 detector at the ep-collider HERA. The decay channel b (b) over bar -> eeX' is selected by identifying the semi-electronic decays of the b-quarks. The total production cross section is measured in the kinematic range given by the photon virtuality Q(2) down to the threshold. The results are compared to next-to-leading-order QCD predictions

Determination of the Integrated Luminosity at HERA using Elastic QED Compton Events

24 pages, 3 tables, 7 figures, submitted to EPJC - See paper for full list of authorsA measurement of the integrated luminosity at the ep collider HERA is presented, exploiting the elastic QED Compton process ep \rightarrow ep. The electron and the photon are detected in the backward calorimeter of the H1 experiment. The integrated luminosity of the data recorded in 2003 to 2007 is determined with a precision of 2.3%. The measurement is found to be compatible with the corresponding result obtained using the Bethe-Heitler process

Combined Inclusive Diffractive Cross Sections Measured with Forward Proton Spectrometers in Deep Inelastic ep\it ep Scattering at HERA

A combination of the inclusive diffractive cross section measurements made by the H1 and ZEUS Collaborations at HERA is presented. The analysis uses samples of diffractive deep inelastic ep scattering data at a centre-of-mass energy √s= 318 Gev where leading protons are detected by dedicated spectrometers. Correlations of systematic uncertainties are taken into account, resulting in an improved precision of the cross section measurement which reaches 6 % for the most precise points. The combined data cover the range 2.5 < Q 2 < 200 GeV 2 in photon virtuality, 0.00035 < xP < 0.09 in proton fractional momentum loss, 0.09 <{pipe}t{pipe}< 0.55 GeV 2 in squared four-momentum transfer at the proton vertex and 0.0018 < β <0.816 in β=x/xP, where x is the Bjorken scaling variable. © 2012 The Author(s).0H1 and ZEUS CollaborationsSCOPUS: ar.jinfo:eu-repo/semantics/publishe