$J/ψ$ photoproduction at HERA
We revise and update an earlier model for $J/ψ$ photoproduction based on a dipole Pomeron exchange. We show that the H1 and ZEUS experimental data reported recently can be well fitted by a soft Pomeron alone.
hep-ph↗
arXiv subjects
L. Jenkovszky
Publications and source records attributed to L. Jenkovszky.
Duality in strong interactions
By introducing Q^2-dependence in resonance-reggeon "soft" dual models with nonlinear trajectories, they are extended to "hard" processes, sharing the property of parton-hadron duality. The resulting object is a two-component complex function of three variables - s,t and Q^2, reducing to classical dual models on the mass shell and to deep inelastic structure functions, or Compton scattering amplitudes - forward and non-forward - otherwise. As a consequence, the small- and large-x behavior of the structure functions is also related by duality. This duality relation holds for each o components (diffractive and non-diffractive for the amplitude or singlet and non-singlet for the structure) separately.
nucl-th↗
How fast do small x structure function rise ? A comparative analysis
We parametrize the small x, singlet component of the proton structure function F_2 by powers and logarithms of 1/x for discrete values of Q^2 between 0.2 and 2000 GeV^2, and compare these parametrizations by applying the criterion of minimal $χ^2$. The obtained values of the fitted parameters may be used to study the evolution of F_2 in Q^2 and/or in discriminating between dynamical models. A slowing-down in the increase of F_2 towards highest available values of Q^2 is revealed. The effect is quantified in terms of the derivative ${\frac{d\ell n F_2(x,Q^2)}{d\ell n (1/x)}}$.
hep-ph↗
Unitarity, (anti)shadowing and the black disc limit
By using realistic models for elastic hadron scattering we demonstrate that at present accelerator energies the $s$-channel unitarity bound is safe, not to be reached until $10^5$ GeV, while the black disc limit is saturated around 1 TeV. It will be followed by a larger transparency of the scattered particles near the center.
hep-ph↗
Approximate solution of the BFKL equation applicable at HERA
We suggest a formula interpolating between the known asymptotic regimes of the BFKL equation as the approximate solution of that equation. The parameters appearing in this interpolation are fitted to the data on deep inelastic scattering in a wide range of the kinematical variables. Care is taken of the large-$x$ domain as well, outside the HERA kinematical region. The boundaries and the interface between various dynamical regimes are also studied.
hep-ph↗
Interpolating between Soft and Hard Dynamics in Deep Inelastic Scattering
An explicit model for the proton structure function interpolating between low- (VMD and Regge behavior)and high-$Q^2$ (GLAP evolution) is suggested. The model is fitted to the experimental data in a wide range of the kinematical variables with emphasis on the low-$x$ HERA data. The boundaries, transition region and interface between various regimes are quantified.
hep-ph↗
The Pomeron in Elastic and Deep Inelastic Scattering
We discuss some properties of the Pomeron in high energy elastic hadron-hadron and deep inelastic lepton-hadron scattering. A number of issues concerning the nature and the origin of the Pomeron are briefly recalled here. The novelty in this paper resides essentially in its presentation; we strive at discussing all these various issues in the following unifying perspective : it is our contention that the Pomeron is one and the same in all reactions. Various examples will be provided illustrating why we do not believe that one should invoke additional tools to describe the data. For pedagogical convenience, we list below the topics to be covered in the following. -- 1. Introduction. How many Pomerons? -- 2. The Pomeron in the $S$-matrix theory -- 3. The Pomeron in QCD -- 4. The Pomeron in deep inelastic scattering -- 5. The Pomeron structure -- 6. (Temporary?) Conclusions
hep-ph↗
Two-Parametric Quantum-Deformed Dual Amplitude
From a 2-parametric deformation of the harmonic oscillator algebra we construct a 4-point dual amplitude with nonlinear trajectories. The earlier versions of the q-deformed dual models are reproduced as limiting cases of the present model.
hep-th↗