Related papers: Pomerons
A brief review on the Dipole Pomeron model is given. The model not only describes data on hadron-hadron interactions, but also allows to describe data on the proton structure function with a $Q^2$ independent intercept. Moreover the chosen…
The Donnachie-Landshoff fit of total cross sections has now become a standard reference for models of total, elastic and diffractive cross-sections. Adopting their philosophy that simple-pole exchanges should account for all data to present…
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…
We review the evidence for the presence of a hard singularity in soft forward amplitudes, and give an estimate of its trajectory and couplings.
We recall the main properties of inclusive particle distributions expected for Pomeron-proton and Pomeron-Pomeron interactions. Due to the small size of the Pomeron we expect larger transverse momenta of secondaries and a smaller…
We show that the introduction of an additional, hard, singularity in soft forward amplitudes enables one to improve considerably the fits using a simple-pole structure for the soft pomeron.
At present there is no correct theory of evolution of F_2(x,Q^2) at small x. It is a mixture of hard and soft pomeron exchange and perturbative QCD very successfully describes the evolution of the hard-pomeron component. This allows the…
The paper presents the $QCD$ description of the hard and semihard processes in the framework of the Wilson operator product expansion. The smooth transition between the cases of the soft and hard Pomerons is obtained.
We consider simple-pole descriptions of soft elastic scattering at small $t$ and $s$, and allow for the presence of a hard pomeron. We have built and analyzed an exhaustive dataset and we show that simple poles provide an excellent…
The hard pomeron first came to light in deep inelastic lepton scattering, but evidence that it contributes also to soft hadronic collisions is reinforced by the fact that it seems to obey a factorisation similar to that of other Regge…
Using the largest data set available, we determine the best values that the data at t=0 (total cross sections and real parts of the hadronic amplitudes) give for the intercepts and couplings of the soft pomeron and of the rho/omega and a/f…
We develop a formalism where the hard and soft pomeron contributions to high energy scattering arise as leading Regge poles of a single kernel in holographic QCD. The kernel is obtained using effective field theory inspired by Regge theory…
The equation for two reggeized gluons with a running QCD coupling constant, proposed earlier on the basis of the bootstrap condition, is investigated by the variational technique in the vacuum channel. The pomeron intercept and slope are…
The low energy $J/\psi$ photoproduction cross-section has been studied on the basis of the Pomeron model. To incorporate the discrepancy between experimental data and the predictionns by the conventional models, i.e. the sum of the soft…
QCD predicts the existence of the perturbative Pomeron and of the Odderon. But both of them appear to be rather difficult to observe experimentally. We describe the experimental status of these two objects, discuss possible reasons for…
In this paper an attempt is made to find an interface of the perturbative BFKL Pomeron with the non-perturbative Pomeron originating from non-perturbative QCD phenomena such as QCD instantons and/or scale anomaly. The main idea is that the…
The introduction of a hard singularity in fits to total cross sections and to the ratio of real to imaginary parts enables to reproduce perfectly the data for sqrt(s)< 100 GeV using only simple-pole parametrisations, both for the soft and…
By using an extended Regge parametrization and taking into account the discrepancies in the high-energy pp and p(bar)p total cross section data, in both accelerator and cosmic-ray regions, we estimate extrema bounds for the soft Pomeron…
Coherence phenomena, the increase with energy of coherence length and the non-universality of parton structure of the effective Pomeron are explained. New hard phenomena directly calculable in QCD such as diffractive electroproduction of…
The proton size, specifically its charge radius, was thought known to about 1% accuracy. Now a new method probing the proton with muons instead of electrons finds a radius about 4% smaller, and to boot gives an uncertainty limit of about…