相关论文: QCD: Quantum Chromodynamic Diffraction
Parton distribution and correlation functions describe the relation between a hadron and the quarks and gluons (or collectively, the partons) within it, and carry rich information on hadron's partonic structure that cannot be calculated by…
Elements of the pomeron phenomenology within the Regge pole exchange picture are recalled. This includes discussion of the high energy behaviour of total cross-sections, the triple pomeron limit of the diffractive dissociation and the…
Parton distribution functions (DFs) are defining expressions of hadron structure. Exploiting the role of effective charges in quantum chromodynamics, an algebraic scheme is described which, given any hadron's valence parton DFs at the…
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…
Deep-inelastic diffractive scaling provides fundamental insight into the QCD pomeron. It is argued that single gluon domination of the structure function, together with the well-known Regge pole property, determines that the pomeron carries…
Jet production in electron-proton collisions at HERA provides a unique testing ground for Quantum Chromodynamics (QCD). Apart from the determination of the strong coupling constant $\alpha_s$, ep jet data may especially be used to gain…
We develop the pQCD description of the diffraction dissociation (DD) of longitudinal photons. We demonstrate that the longitudinal diffractive structure function does not factor into the flux of pomerons and the partonic structure function…
The theoretical framework for a next-to-leading order QCD analysis of the spin-dependent parton densities Delta f^{gamma}(x,Q^2) of the longitudinally polarized photon and of its structure function g_1^{gamma}(x,Q^2) is reviewed in some…
The QCD structure of the electroweak bosons is reviewed and the lepton structure function is defined and calculated. The leading order splitting functions of electron into quarks are extracted, showing an important contribution from…
New results on charm and beauty electroproduction from the H1 and ZEUS Collaborations at the ep collider HERA are presented. Differential cross sections are compared to a next-to-leading order QCD calculation. The heavy quark contributions,…
I investigate the theoretical uncertainties on the predictions for the longitudinal structure function. I compare the predictions using fixed-order perturbative QCD, higher twist corrections, small-x resummations and the dipole picture. I…
We discuss the observed scaling of the small-x diffractive and total deep-inelastic structure functions at HERA. We argue that the parton interpretation of Buchm\"uller and Hebecker can be understood within QCD as the appearance of the…
We study both polarized and unpolarized proton structure functions in the kinematical region of large Bjorken x and four-momentum transfer of few GeV^2. In this region the phenomenon of parton-hadron duality takes place between the smooth…
This contribution reviews the main achievements in inclusive measurements made by the H1 and ZEUS collaborations during the first phase of HERA data taking. The QCD analysis of these data by both collaborations are described. The case for a…
Deep-inelastic production of heavy quarks at HERA, especially charm, is an excellent signal to measure the gluon distribution in the proton at small $x$ values. By measuring various differential distributions of the heavy quarks this…
This paper presents the first analysis of diffractive photon dissociation events in deep inelastic positron-proton scattering at HERA in which the proton in the final state is detected and its momentum measured. The events are selected by…
In this talk, I focus on the quark-gluon structure of hadrons probed using high-energy hadron beams. I start with a brief review on recent major achievements in measuring parton distributions of the nucleon, pion, and kaon, with hadron…
A review of HERA measurements of structure functions, fragmentation functions and forward jet production is presented.
Measurements of the diffractive structure function $F_2^{D(3)}(x_{\PO}, \beta, Q^2)$, describing the process $ep \to eXY$, are presented in the two kinematic regions $0.4 \leq Q^2 \leq 5$, ${\rm GeV}^2$, $0.001 \leq \beta \leq 0.65$, and…
We present a novel analysis of diffractive DIS data, in which the input parton distributions of the Pomeron are parameterised using perturbative QCD expressions. In addition to the usual two-gluon model for the perturbative Pomeron, we…