Related papers: Experimental approaches to low x at HERA
Heavy meson production in reactions with nuclei is an active new frontier to understand QCD dynamics and the process of hadronization in nuclear matter. Measurements in various colliding systems at RHIC and LHC, including Pb-Pb, Xe-Xe, O-O,…
New Results on the measurement of the proton structure function F_2(x,Q^2) are reported for momentum transfers squared Q^2 >= 1.5 GeV^2 and Bjorken x >= 3.5 10^{-5} using data collected by the HERA experiments H1 and ZEUS in 1994. F_2…
I review the status of perturbative QCD calculations for jet production in eP-scattering at HERA. I will discuss possibilities of combining fixed order, especially higher order, calculations and parton showers.
The HERA diffractive structure function data are interpreted in terms of `diffractive parton distributions' which satisfy DGLAP evolution. These distributions are modeled assuming that the scattering takes place off a colour singlet…
The cross section of diffractive deep-inelastic scattering ep \rightarrow eXp is measured, where the system X contains at least two jets and the leading final state proton is detected in the H1 Forward Proton Spectrometer. The measurement…
This presentation reports recent results from the hadronic final state in DIS at HERA. Forward jet and $\pi^0$ production have been measured by the H1 experiment. The forward jet production cross section shows significant deviation from the…
Selected recent data from collider experiments pertaining to the understanding of QCD at low Bjorken-x are reviewed. The status of QCD and Regge factorisation in hard diffractive interactions is discussed in terms of data from HERA and the…
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…
Jet-energy loss is an important sign of the creation of Quark-Gluon Plasma in heavy-ion collisions. High transverse momentum ($p_T$) partons are produced at the moment of initial hard scattering and are modified as a result of their…
The production of jets is studied in collisions of virtual photons, specifically for applications at HERA. Photon flux factors are convoluted with matrix elements involving either direct or resolved photons and, for the latter, with parton…
Use of HERA jet production cross sections can extend our knowledge of the gluon parton distribution function and yield accurate measurements of $\alpha_s(M_Z)$ in addition to illustrating the running of $\alpha_s$ with scale.
A review is presented on studies of high $E_T$ jet production and production of photon, $W$ and $Z$ associated with jets from the HERA and Tevatron experiments. Such studies have been used to examine the Standard Model (SM) in the area of…
Between 1992 and 2007, the HERA accelerator provided $ep$ collisions at center of mass energies beyond $300 \ {\rm GeV}$ at the interaction points of the H1 and ZEUS experiments. Interesting results to emerge relate to the newly accessed…
We study the evolution of parton distributions down to low scales by considering several of their Mellin moments. For the initial conditions, we use a broad array of current parton density fits. Confirming earlier findings in the…
We recall our recent description of quark parton densities of the proton at $Q^2=4 GeV^2$ in terms of Fermi-Dirac distributions parametrized with very few free parameters. We have also proposed some simple assumptions to relate unpolarized…
As the signature manifestation of QCD in high energy nuclear collisions jet production provides essential tests of that theory. But event-wise jet reconstruction can be complex and susceptible to measurement bias. And QCD theory in the form…
The cross section for producing three high transverse energy jets with a three-jet invariant mass of M_3J > 50 GeV has been measured in photoproduction at HERA. The angular distribution of the three jets is presented and found to be…
An overview of recent results from the H1 and ZEUS collaborations on vector meson production in electron-proton collisions at HERA is given. For diffractive vector meson production the energy dependence is discussed. The dependences on…
Internal jet structure in dijet production in deep-inelastic scattering is measured with the H1 detector at HERA. Jets with transverse energies ET,Breit > 5 GeV are selected in the Breit frame employing k_perp and cone jet algorithms. In…
The inclusive photoproduction of D\ast mesons and of D\ast-tagged dijets is investigated with the H1 detector at the ep collider HERA. The kinematic region covers small photon virtualities Q2 < 2 GeV2 and photon-proton centre-of-mass…