Related papers: PDF Fits at HERA
Recent structure function results from the H1 and ZEUS Collaborations are presented. The data cover a wide kinematic range of squared four-momentum transfers Q^2, from 0.2 GeV^2 to 30000 GeV^2, and Bjorken x between 5*10^-6 and 0.65. Data…
We calculate the cross section of charm photoproduction at HERA collider in the framework of the kt-factorization QCD approach. Our analysis cover the inclusive charm production as well as charm and associated jet production processes. Both…
The xFitter project (former HERAFitter project) is an open-source package that provides a framework for the determination of the parton distribution functions (PDFs) of the proton for many different kinds of analyses in Quantum…
We have presented the results of our next-to-next-to-leading order (NNLO) QCD analysis of nuclear parton distribution functions (nuclear PDFs) [Phys. Rev. D 93 (2016) 014026, arXiv:1601.00939 [hep-ph]] using all available neutral current…
Experiments at the LHC are collecting a wealth of data with an unprecedented level of precision. As a consequence, the theoretical error is now starting to lag behind the experimental one, and a ceaseless effort is required to reduce the…
Since its start of data taking, the LHC has provided an impressive wealth of information on the quark and gluon structure of the proton. Indeed, modern global analyses of parton distribution functions (PDFs) include a wide range of LHC…
The H1 and ZEUS experiments are measuring diffractive interactions in ep collisions at HERA. Performing QCD fits of these data with NLO DGLAP, diffractive parton distribution functions can be calculated. These diffractive PDFs can be used…
Nuclear parton distribution functions (nPDFs) can be determined in a global QCD analysis using a wide range of experimental data. In addition to older fixed-target deep inelastic scattering and Drell-Yan (DY) dilepton production data,…
We provide an assessment of the impact of parton distributions on the determination of LHC processes, and of the accuracy with which parton distributions (PDFs) can be extracted from data, in particular from current and forthcoming HERA…
HERAFitter is an open-source package that provides a framework for the determination of the parton distribution functions (PDFs) of the proton and for many different kinds of analyses in Quantum Chromodynamics (QCD). It encodes results from…
We provide an updated recommendation for the usage of sets of parton distribution functions (PDFs) and the assessment of PDF and PDF+$\alpha_s$ uncertainties suitable for applications at the LHC Run II. We review developments since the…
The interest into parton distribution functions (PDFs) and fragmentation functions (FFs) in current high energy physics research is twofold. On the one hand, they are fundamental objects to conduct precision phenomenology studies, e.g. at…
The kinematic region covered by the LHC experiments probes low values of Bjorken-$x$. At the scale relevant for $W$ and $Z$ production the central rapidity region covers $10^{-3} < x < 10^{-1}$. This means that it is the HERA data which…
We discuss implementation of the LHC experimental data sets in the new CT18 global analysis of quantum chromodynamics (QCD) at the next-to-next-leading order of the QCD coupling strength. New methodological developments in the fitting…
Recent results from the HERA ep collider are reviewed in these proceedings. The results are from measurements that probe QCD at high-energy scales, as defined by $Q^2$, the four-momentum-transfer squared of the collisions. These…
We determine the strong coupling alpha_s from a next-to-leading order analysis of processes used for the NNPDF2.1 parton determination, which includes data from neutral and charged current deep-inelastic scattering, Drell-Yan and inclusive…
The precision measurements of the strong coupling constant, alphas, and its energy-scale dependence carried out at HERA by the H1 and ZEUS Collaborations are reviewed. An average value of alphas(Mz) = 0.1186 +- 0.0011 (exp.) +- 0.0050 (th.)…
The accurate determination of the Parton Distribution Functions (PDFs) of the proton is an essential ingredient of the Large Hadron Collider (LHC) program. PDF uncertainties impact a wide range of processes, from Higgs boson…
Parton Density Functions (PDFs) and their uncertainties are extremely important topics for both the Tevatron and the LHC. Experiments at the Tevatron can enhance this knowledge not only by constraining the PDF fits, but also by developing…
Inclusive charm meson production cross sections in the deep inelastic scattering and photoproduction regimes are compared with QCD leading and next-to-leading (NLO) calculations. The NLO predictions are significantly below the data in some…