Related papers: Experimental approaches to low x at HERA
We investigate the Q2 evolution of parton distributions at small x values, recently obtained in the case of soft initial conditions. The results are in excellent agreement with deep inelastic scattering experimental data from HERA.
In order to probe the dynamics of parton evolution in deep inelastic scattering at small x, high-p_T particles produced centrally in pseudorapidity are studied. In the BFKL mechanism gluon radiation is expected to be more abundant than for…
In this talk I review the low x QCD experimental results from HERA and their theoretical underpinnings. In particular, I discuss the structure function $F_2$, large rapidity gap events, pomeron structure functions and $J/\psi$ production.
We discuss the inclusive jet production at HERA in the next-to-leading logarithm approximation. Theoretical uncertainties are considered in some details. We show the importance of the jet rapidity distribution to constrain the parton…
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…
This talk is a rather sceptical review of our knowledge and understanding of deep inelastic scattering at low x (high energy). We show that the well known success of the DGLAP evolution equations in describing of experimental HERA data…
It is reported on an analysis of Phi-meson electroproduction at small Bjorken-x within the handbag approach. The amplitudes factorize into generalized parton distributions and a partonic subprocess, electroproduction off gluons. Cross…
This article describes different approaches to investigate the behavior of parton evolution in the proton by exploiting various aspects of the hadronic final state produced in Deep Inelastic Scattering Events at HERA.
Two-jet production in deep-inelastic electron-proton scattering has been studied for $160<Q^2<1280$~GeV$^2$, $0.01<x<0.1$ and $0.04<y<0.95$ with the ZEUS detector at HERA. The kinematic properties of the jets and the jet production rates…
We estimate the cross-section and asymmetry relevant for the production of forward jets in polarised deep inelastic scattering in the region of small values of $x$ which can be probed at possible polarised HERA measurements. The kinematical…
Recent results from the ep (electron-proton) collider HERA are presented. Jet production and diffraction type reactions allow tests of predictions of Quantum Chromodynamics (QCD). Jet measurements are used to improve the combined H1-ZEUS…
It has been found that recent results on forward jet production from deep inelastic scattering can neither be reproduced by models which are based on leading order alpha_s QCD matrix elements and parton showers nor by next-to-leading order…
The photoproduction of Drell-Yan lepton pairs at HERA is studied. We show that in the backward rapidity region the cross section is strongly sensitive to the small-$x$ behaviour of the quark distributions in the proton, and that with…
We investigate the Q^2 evolution of parton distributions at small x values, recently obtained in the case of soft initial conditions. The results are in excellent agreement with deep inelastic scattering experimental data from HERA.
We present a global fit to HERA data on the reduced cross section measured in electron-proton collisions in the region of small Bjorken-$x$: $x\le x_0=10^{-2}$ and moderate to high values of the virtuality $Q^2<Q^2_{max}=650$ GeV$^2$. The…
Two-jet cross sections in deep inelastic scattering at HERA are calculated in next-to-leading order. The QCD corrections are implemented in a new $ep\rightarrow n$ jets event generator, MEPJET, which allows to analyze arbitrary jet…
I review recent developments in the study of the low-x partonic content of protons and nuclei, with a focus on the latter, as one expects possible deviations from linear QCD evolution to be most pronounced in that case. I give examples of…
Dijet production in DIS is an important laboratory for testing our understanding of perturbative QCD. Flexible NLO Monte Carlo programs allow to investigate general jet definition schemes. For forward jet production at $p_{Tj} \approx Q$…
The transition between photoproduction and deep-inelastic scattering is investigated in jet production at the HERA ep collider, using data collected by the H1 experiment. Measurements of the differential inclusive jet cross-sections…
Measurements of the hadronic final state at HERA are reviewed, which aim at the investigation of the parton dynamics of the proton at small Bjorken x.