arXiv subjects

L. L. Jenkovszky

Publications and source records attributed to L. L. Jenkovszky.

At least 37 records · Page 2Linked to original sources

arXiv2003

A Kinematically Complete Analysis of the CLAS data on the Proton Structure Function $F_2$ in a Regge-Dual model

The recently measured inclusive electron-proton cross section in the nucleon resonance region, performed with the CLAS detector at the Thomas Jefferson Laboratory, has provided new data for the nucleon structure function $F_2$ with previously unavailable precision. In this paper we propose a description of these experimental data based on a Regge-dual model for $F_2$. The basic inputs in the model are nonlinear complex Regge trajectories producing both isobar resonances and a smooth background. The model is tested against the experimental data, and the $Q^2-$ dependence of the moments is calculated. The fitted model for the structure function (inclusive cross section) is a limiting case of the more general scattering amplitude equally applicable to deeply virtual Compton scattering (DVCS). The connection between the two is discussed.

hep-ph↗

arXiv2003

Generalized distribution amplitudes: new tools to study hadrons' structure and interactions

A non-perturbative approach to Generalized Parton Distributions, and to Deeply Virtual Compton Scattering in particular, based on off mass shell extension of dual amplitudes with Mandelstam analyticity (DAMA) is developed with the spin and helicity structure as well as the threshold behavior accounted for. The model is tested against the data on deep inelastic electron-proton scattering from JLab.

hep-ph↗

arXiv2003

Ultra-high energy neutrino-nucleon interactions

Ultra-high energy ($E_ν>10^8 $ GeV) neutrino-nucleon total cross sections $σ^{νN}$ are estimated from a soft non-perturbative model complemented by an approximate QCD evolution, explicitly calculated. The resulting asymptotic energy behavior of the neutrino-nucleon charged-current total cross section is derived analytically and predictions concerning the observation of ultra-high energy neutrinos in future experiments are presented.

hep-ph↗

arXiv2003

The Pomeron in Exclusive $J/ψ$ Vector Meson Production

An earlier developed model for vector meson photoproduction, based on a dipole Pomeron exchange, is extended to electroproduction. Universality of the non linear Pomeron trajectory is tested by fitting the model to ZEUS and H1 data as well as to CDF data on $\bar pp$ elastic scattering

hep-ph↗

arXiv2003

The Pomeron In Exclusive Vector Meson Production

hep-ph↗

arXiv2002

Low-energy diffraction; a direct-channel point of view: the background

We argue that at low-energies, typical of the resonance region, the contribution from direct-channel exotic trajectories replaces the Pomeron exchange, typical of high energies. A dual model realizing this idea is suggested. While at high energies it matches the Regge pole behavior, dominated by a Pomeron exchange, at low energies it produces a smooth, structureless behavior of the total cross section determined by a direct-channel nonlinear exotic trajectory, dual to the Pomeron exchange.

hep-ph↗

arXiv2002

Can supercooling explain the HBT puzzle?

Possible hadronization of supercooled QGP, created in heavy ion collisions at RHIC and SPS, is discussed within a Bjorken hydrodynamic model. Such a hadronization is expected to be a very fast shock-like process, what, if hadronization coincides or shortly followed by freeze out, could explain a part of the HBT puzzle, i.e. the flash-like particle emission ($R_{out}/R_{side}\approx 1$). HBT data also show that the expansion time before freeze out is very short ($\sim 6-10 fm/c$). In this work we discuss question of supercooled QGP and the timescale of the reaction.

hep-ph↗

arXiv2002

On the Distribution of Secondaries at High Energies

We show within a geometrical model developed in earlier papers that multiplicity distributions are cut off at large multiplicities. The position and motion of the cut-off point is related to geometrical- and KNO scaling and their violation, in particular by the rise of the ratio $σ_{el}/σ_{t}.$ At the LHC energies a change of the regime, connected with the transition from shadowing to antishadowing is expected.

hep-ph↗

arXiv2002

Explicit model realizing parton-hadron duality

An explicit model realizing parton-hadron duality and fitting the data is suggested. Complex nonlinear Regge trajectories are important ingredients of the model. The inclusion of $Δ$ and $N^*$ trajectories should account for all resonances in the direct channel. The exotic trajectory is responsible for the smooth background.

hep-ph↗

arXiv2001

Dual Properties of the Structure Functions

By using the concept of duality between direct channel resonances and Regge exchanges we relate the small- and large-$x$ behavior of the structure functions. We show that even a single resonance exhibits Bjorken scaling at large $Q^2$.

hep-ph↗

arXiv2000

Analytic model of Regge trajectories

A model for a Regge trajectory compatible with the threshold behavior required by unitarity and asymptotics in agreement with analyticity constraints is given in explicit form. The model is confronted in the time-like region with widths and masses of the mesonic resonances and, in the space-like region, the $ρ$ trajectory is compared with predictions derived from $π-N$ charge-exchange reaction. Breaking of the exchange degeneracy is studied in the model and its effect on both the masses and widths is determined.

hep-ph↗

arXiv2000

Finite sum of gluon ladders and high energy cross sections

A model for the Pomeron at $t=0$ is suggested. It is based on the idea of a finite sum of ladder diagrams in QCD. Accordingly, the number of $s$-channel gluon rungs and correspondingly the powers of logarithms in the forward scattering amplitude depends on the phase space (energy) available, i.e. as energy increases, progressively new prongs with additional gluon rungs in the $s$-channel open. Explicit expressions for the total cross section involving two and three rungs or, alternatively, three and four prongs (with $\ln^2(s)$ and $\ln^3(s)$ as highest terms, respectively) are fitted to the proton-proton and proton-antiproton total cross section data in the accelerator region. Both QCD calculation and fits to the data indicate fast convergence of the series. In the fit, two terms (a constant and a logarithmically rising one) almost saturate the whole series, the $\ln^2(s)$ term being small and the next one, $\ln^3(s)$, negligible. Theoretical predictions for the photon-photon total cross section are also given.

hep-ph↗

arXiv2000

The Pomeron as a Finite Sum of Gluon Ladder

A model for the Pomeron at t=0 is suggested. It is based on the idea of a finite sum of ladder diagrams in QCD. Accordingly, the number of s-channel gluon rungs and correspondingly the powers of logarithms in the forward scattering amplitude depends on the phase space (energy) available, i.e. as energy increases, progressively new prongs with additional gluon rungs in the s-channel open. Explicit expressions for the total cross section involving two and three rungs or, alternatively, three and four prongs (with $\ln^2(s)$ and $\ln^3(s)$ as highest terms) is fitted to the proton-proton and proton-antiproton total cross section data in the accelerator region.

hep-ph↗

arXiv1999

Analytic Model of a Regge Trajectory in the Space-like and Time-like Regions

A model for a Regge trajectory compatible with the threshold behavior required by unitarity and asymptotics in agreement with Mandelstam analyticity is analyzed and confronted with the experimental data on the spectrum of the $ρ$ trajectory as well as those on the $π^- p\to π^0 n$ charge-exchange reaction. The fitted trajectory deviates considerably from a linear one both in the space-like and time-like regions, matching nicely between the two.

hep-ph↗

arXiv1999

Triple Pomeron and Proton Diffraction Dissociation

We consider proton diffraction dissociation in the dipole Pomeron model, where the Pomeron is represented by a double pole in the $J-$plane, and show that unitarity can be satisfied without decoupling of the triple Pomeron vertex. Differential and total diffractive cross sections for the reaction $\bar{p}+p \to \bar{p}+X$ are analyzed and reproduced in this model.

hep-ph↗

arXiv1999

Fixed-Angle Elastic Hadron Scattering

The scattering amplitude in the dual model with Mandelstam analyticity and trajectory $α(s)=α_{0}-γ\ln [ (1+β\sqrt{s_{0} -s})/(1+ β\sqrt{s_{0}})]$ is studied in the limit $s,|t|\to \infty, s/t=const.$ By using the saddle point method, a series decomposition for the scattering amplitude is obtained, with the leading and two sub-leading terms calculated explicitly.

hep-ph↗

arXiv1998

Hadron Diffraction Dissociation and the Triple Pomeron Vertex

Hadron diffraction dissociation is considered in the dipole Pomeron model where the Pomeron is represented by a double pole in the J-plane. We find that unitarity is satisfied without decoupling of the triple Pomeron vertex. The reaction bar{p}+p --> bar{p}+X is analysed.

hep-ph↗

arXiv1998

Photoproduction of Heavy Vector Mesons at HERA -- A Testfield for Diffraction

Exclusive diffractive photoproduction of heavy vector mesons (V=phi, J/psi and Upsilon) at HERA is studied in a model employing a dipole Pomeron exchange (P) with an inelastic gamma-P-V vertex. The model is fitted to the data on dsigma/dt, B and elastic sigma for Q^2=0 and beyond the threshold region. The elastic cross sections for both phi and J/psi photoproduction show a moderate increase within the HERA energy region. The flattening of the slope B(s) (little or no shrinkage) for J/psi is not correlated with the slope of the Pomeron trajectory. Estimates for Upsilon photoproduction at HERA are given.

hep-ph↗