arXiv subjects
Publications and source records attributed to G. Wilk.
We demonstrate that hadron production viewed as formation of specific stochastic network can explain in natural way the power-law distributions of transverse mass spectra of pions found recently, which seem to substitute the expected Boltzmann statistical factor.
The application of information theory approach (both in its extensive and nonextensive versions) to high energy multiparticle processes is discussed and confronted with experimental data on e+e- annihilation processes, pp and \bar{p}p scatterings and heavy ion collisions.
We argue that recent data on fluctuations observed in heavy ion collisions show non-monotonic behaviour as function of number of participants (or "wounded nucleons") N_W. When interpreted in thermodynamical approach this result can be associated with a possible structure occuring in the corresponding equation of state (EoS). This in turn could be further interpreted as due to the occurence of some characteristic points (like "softest point" or "critical point") of EoS discussed in the literature and therefore be regarded as a possible signal of the QGP formation in such collisions. We show, however, that the actual situation is still far from being clear and calls for more investigations of fluctuation phenomena in multiparticle production processes to be performed.
The new method of numerical modelling of Bose-Einstein correlations observed in all kinds of multiparticle production processes is proposed.
It is demonstrated how to obtain the least biased description of the single particle spectra measured in all multiparticle production processes by using information theory approach (known also as MaxEnt approach). The case of e+e- annihilation in hadrons process is discussed in more detail as an example. Comparison between MaxEnt approach and simple dynamical model based on the cascade process is presented as well.
Nature is full of random networks of complex topology describing such apparently disparate systems as biological, economical or informatical ones. Their most characteristic feature is the apparent scale-free character of interconnections between nodes. Using an information theory approach, we show that maximalization of information entropy leads to a wide spectrum of possible types of distributions including, in the case of nonextensive information entropy, the power-like scale-free distributions characteristic of complex systems.
We present an overview of information theory approach (both in its extensive and nonextensive versions) applied to high energy multiparticle production processes. It will be illustrated by analysis of single particle distributions measured in proton-proton, proton-antiproton and nuclear collisions. We shall demonstrate the particular role played by the nonextensivity parameter q in such analysis as summarizing our knowledge on the fluctuations existed in hadronizing system.
Using a specific version of thermal Quantum Field Theory (QFT), supplemented by operator-field evolution of the Langevin type, we discuss two issues concerning the Bose Einstein correlations (BEC): the origin of different possible coherent behaviour of the emitting source and the origin of the observed shape of the BEC function $C_2(Q)$. We demonstrate that previous conjectures in this matter obtained by other approaches are confirmed and have received complementary explanation.
We show that a recently proposed derivation of Bose-Einstein correlations (BEC) by means of a specific version of thermal Quantum Field Theory (QFT), supplemented by operator-field evolution of the Langevin type, allows for a deeper understanding of the possible coherent behaviour of the emitting source and a clear identification of the origin of the observed shape of the BEC function $C_2(Q)$. Previous conjectures in this matter obtained by other approaches are confirmed and have received complementary explanation.
Using the information theory approach, in both its extensive and nonextensive versions, we estimate the inelasticity parameter $K$ of hadronic reactions together with its distribution and energy dependence from $p\bar{p}$ and $pp$ data. We find that the inelasticity remains essentially constant in energy except for a variation around $K\sim 0.5$, as was originally expected.
We have calculated the mass distribution ($dσ/dM_X$) as observed by UA8 Collaboration in the inclusive reaction $p \bar p \to p X \bar p$ at $\sqrt s = 630 GeV$, using the Interacting Gluon Model (IGM) with Double Pomeron Exchange included. The only new parameter is the $IP IP$ cross section, which we can extract from fitting experimental data. We compare our results with the values obtained in the UA8 study. Assuming a constant Pomeron-Pomeron total cross section ($σ_{IP IP} = 1 mb$), we make predictions for $dσ/dM_X$ at Tevatron and LHC energies.
We discuss the leading particle spectra and diffractive mass spectra from the novel point of view, namely by treating them as particular examples of the general energy flow phenomena taking place in the multiparticle production processes. We argue that they show a high degree of universality what allows for their simple description in terms of the Interacting Gluon Model developed by us some time ago.
We present calculation of influence caused by nucleon Fermi motion on the parton distributions in nuclei. Our approach is based on the model where momenta of valence partons have some primordial distribution inside the hadron at rest, which is either provided by a statistical considerations or calculated using spherically symmetric Gaussian distribution with a width derived from the Heisenberg uncertainty relation. The sea parton contribution emerges from the similar Gaussian distribution with a width dictated by the presence of virtual pions in hadron. We show that the influence of Fermi motion changes substantially the nucleonic structure function inside the nucleus in the right direction and therefore should be considered seriously in all attempts devoted to explain the experimentally observed EMC effect for $x_{Bj} > 0.1$.
The limitations of the recently proposed new method of numerical modelling of Bose-Einstein correlations (BEC) are explicitly demonstrated. It is then argued that BEC should still be considered as emerging from the correlations of fluctuations, however they have to be modelled first in any Monte Carlo event generator (MCEG) and not added {\it a posteriori} to the existing output of some MCEG.
The apparently observed power-like abundance of elements in Universe is discussed in more detail with special emphasis put on the strangelets.
We present a short review of traces of nonextensivity in particle physics due to fluctuations.
We demonstrate how Bose-Einstein correlations emerge from the correlations of fluctuations allowing for their extremely simple and fast numerical modelling. Both the advantages and limitations of this new method of implementation of BEC in the numerical modelling of high energy multiparticle processes are outlined and discussed. First applications to description of $e^+e^-$ data are given.
We provide description of rapidity spectra of particles produced in p-anti-p collisions using anomalous diffusion approach to account for their non-equilibrium character. In particular, we exhibit connection between multiproduction processes and anomalous diffusion described through the nonlinear Focker-Planck equation with nonlinearity given by the nonextensivity parameter q describing the underlying Tsallis q-statistics and demonstrate how it leads to the Feynman scaling violation in these collisions. The q parameter obtained this way turns out to be closely connected to parameter 1/k converting the original poissonian multiplicity distribution to its observed Negative Binomial form. The inelasticity of reaction has been also calculated and found to slightly decrease with the increasing energy of reaction. Keywords: inelasticity, rapidity spectra, nonextensivity