A combination is presented of the inclusive deep inelastic cross sections measured by the H1 and ZEUS Collaborations in neutral and charged current unpolarised e ± p scattering at HERA during the period 1994-2000. The data span six orders of magnitude in negative four-momentum-transfer squared, Q 2 , and in Bjorken x. The combination method used takes the correlations of systematic uncertainties into account, resulting in an improved accuracy. The combined data are the sole input in a NLO QCD analysis which determines a new set of parton distributions, HERAPDF1.0, with small experimental uncertainties. This set includes an estimate of the model and parametrisation uncertainties of the fit result.

20 pagesInternational audienceWe provide a concise overview on transverse momentum dependent (TMD) parton distribution functions, their application to topical issues in high-energy physics phenomenology, and their theoretical connections with QCD resummation, evolution and factorization theorems. We illustrate the use of TMDs via examples of multi-scale problems in hadronic collisions. These include transverse momentum q_T spectra of Higgs and vector bosons for low q_T, and azimuthal correlations in the production of multiple jets associated with heavy bosons at large jet masses. We discuss computational tools for TMDs, and present an application of a new tool, TMDlib, to parton density fits and parameterizations

Predictions for charged hadron, identified light hadron, quarkonium, photon, jet and gauge bosons in p+ Pb collisions at [Formula: see text] are compiled and compared. When test run data are available, they are compared to the model predictions.

At the Large Hadron Collider (LHC) it will become possible for the first time to investigate experimentally the forward region in hadron-hadron collisions via high-p T processes. In the LHC forward kinematics QCD logarithmic corrections in the hard transverse momentum and in the large rapidity interval may both be quantitatively significant. We analyze the hadroproduction of forward jets in the framework of QCD high-energy factorization, which allows one to resum consistently both kinds of corrections to higher orders in QCD perturbation theory. We compute the short-distance matrix elements needed to evaluate the factorization formula at fully exclusive level. We discuss numerically dynamical features of multi-gluon emission at large angle encoded in the factorizing high-energy amplitudes.

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