相关论文: The Two Pomerons

Non-linear effects in hadronic interactions are treated by means of enhanced pomeron diagrams, assuming that pomeron-pomeron coupling is dominated by soft partonic processes. It is shown that the approach allows to resolve a seeming…

We discuss whether the diffractive structure functions defined by current experiments at HERA are indeed probing the partonic structure function of the pomeron. We observe that the {\it pseudorapidity} cuts commonly employed require that…

In this paper, we investigate the stability properties of soft gluons in SIBYLL 2.1 with reference to its original version 1.7 that corresponds to hadronic hard interactions. In order to investigate the stability structures, we classify the…

Hadron spectroscopy has received revitalised interest due to the discovery of states with unexpected properties. Discussed are the recent findings at BABAR, CLEO, BELLE and BES. A detailed report is given on the many experiments reporting…

HERA, the electron-proton collider, enables to probe the proton with a high resolving power due to the deep inelastic scattering reactions at high $Q^2$ values. In the low $Q^2$ region, one can study the properties of the photon. The large…

Benefiting from the high statistics from $e^+e^-$ experiments at the $Z^0$ resonance, it is possible to impose strong two-jet cuts on the data without losing the statistical significance. In these events perturbative activity is suppressed…

A selection of results from the H1 and ZEUS experiments at HERA are reviewed, particularly in the area of deep inelastic scattering and diffraction. Quantum chromodynamics gives a good explanation of these data down to surprisingly low…

We introduce soft colour interactions as a novel mechanism to understand the observed events with large rapidity gaps in $ep$ collisions at HERA. Colour exchanges between produced partons and colour-charges in the proton remnant modifies…

The long standing mystery of smallness of diffractive dissociation of hadrons to large effective masses (the Pomeron-proton cross section is only 2 mb) witnesses that the gluonic clouds of valence quarks are so small (r_0=0.3fm) that soft…

The formation of hadrons is a fundamental process in nature that can be investigated at particle colliders. As several recent findings demonstrate, with $\mathrm{e^+e^-}$ collisions as a "vacuum-like" reference at one extreme, and central…

We revisit diffractive and exclusive W production at hadron colliders in different models for soft colour exchanges. The process pp to p[WX]p, and in particular a W charge asymmetry, has been suggested as a way to discriminate diffractive…

Two-photon exchange contributions to elastic electron-scattering are reviewed. The apparent discrepancy in the extraction of elastic nucleon form factors between unpolarized Rosenbluth and polarization transfer experiments is discussed, as…

Hadron production in single and central diffraction dissociation is studied in a model which includes soft hadron interaction as controlled by a supercritical pomeron parametrization and hard diffraction. Within this model, particle…

In this talk I give a short review of theoretical results on the properties of hadrons in cold, equilibrium nuclear matter. I then discuss the observable consequences of any changes of these properties inside the medium in actual…

Measurements of diffractive phenomena observed at HERA and the Tevatron are reviewed. A short introduction to the theoretical background is presented where colour singlet exchange reactions are discussed and the diffractive contribution and…

Using the analytical expression for transverse momentum dependent (TMD) gluon density in a proton, a self-consistent simultaneous description of low $Q^2$ data on proton structure function $F_2(x,Q^2)$, reduced cross section for the…

Results of experiments probing the structure of the pomeron at hadron colliders and at HERA are reviewed. By renormalizing the pomeron flux factor in diffraction dissociation as dictated by unitarity, a picture emerges from the data in…

We present experimental evidences for the existence of a semi-hard scale in light hadrons. This includes the suppression of gluon radiation that is seen in high mass hadron diffraction; the weak energy dependence of hadronic total cross…

The tensor-pomeron model is applied to low-x deep-inelastic lepton-nucleon scattering and photoproduction. We consider c.m. energies in the range 6 - 318 GeV and Q^2 < 50 GeV^2. In addition to the soft tensor pomeron, which has proven quite…

I review various theoretical questions that arise from data from HERA and the Tevatron, and which are relevant for the LHC. They range from soft physics, such as the total cross section, to hard physics, such as Higgs production. In…