arXiv subjects
Publications and source records attributed to Z. Wlodarczyk.
We provide arguments that event-by-event (EBE) analysis of multiparticle production data are ideal place to search for the possible fluctuation of temperature characterizing hadronizing source in thermodynamical approach.
We discuss the effect of nonextensivity of the emitting source on the Bose-Einstein correlations (BEC). This is done numerically by comparing cascade hadronization model (CAS), which is known to exhibit fractal structure in both space-time and phase-space, with its equivalent obtained from the information theory approach (MaxEnt), in which hadronization proceeds uniformly in the phase-space. To this end we have developed a new method of accounting for BEC in Monte Carlo event generators, which preserves all kinematics of the hadronization process.
The statistical methods based on the classical Boltzmann-Gibbs (BG) approach are at heart of essentially all descriptions of multiparticle production processes. In many cases, however, one observes some deviations from the expected behaviour. It is also known that conditions necessary for the BG statistics to apply are usually satisfied only approximately. Two attitudes are possible in such situations: either to abandon statistical approach trying some other model or to generalise it to the so called nonextensive statistics (widely used in the similar circumstances in many other branches of physics). We shall provide here an overview of possible imprints of non-extensitivity existing both in high energy cosmic ray physics and in multiparticle production processes in hadronic collisions, in particular in heavy ion collisions.
To describe high energy collisions one widely uses thermodynamical methods and concepts which follow the classical Boltzmann-Gibbs (BG) approach. In many cases, however, either some deviations from the expected behaviour are observed experimentally or it is known that the conditions necessary for BG to apply are satisfied only approximately. In other branches of physics where such situations are ubiquitous, the popular remedy is to resort, instead, to the so called nonextensive statistics, the most popular example of which is Tsallis statistics. We shall provide here an overview of possible imprints of non-extensitivity existing both in high energy cosmic ray physics and in multiparticle production processes in hadronic collisions, in particular in heavy ion collisions. Some novel proposition for the interpretation of the nonextensitivity parameter q present in such circumstances will be discussed in more detail.
We discuss the possible imprints of strangelets (i.e., lumps of Strange Quark Matter) in Chacaltaya experimental data using model of propagation of such objects through the atmosphere developed by us recently.
We demonstrate that the apparently ad hoc parametrization of the particle production spectra discussed in the literature and used in description of cosmic ray data can be derived from the information theory approach to multiparticle production processes. In particular, the violation of the Feynman scaling law can be interpreted as a manifestation of nonextensivity of the production processes.
We argue that atmospheric cascades can be regarded as example of the self-organized criticality and studied by using Levy flights and nonextensive approach. It allows us to understand the scale-invariant energy fluctuations inside cascades in a natural way.
The hypothesis is discussed that muon bundles of extremaly high multiplicity observed recently by ALEPH detector (in the dedicated cosmic-ray run) can originate from the strangelets colliding with the atmosphere.
Recently we have demostrated that the nonextensitivity parameter q occuring in some applications of Tsallis statistics (known also as index of the corresponding Lévy distribution) is, in the q>1 case, given entirely by the fluctuations of the parameters of the usual exponential distribution. We show here that this interpretation is valid also for the q<1 case. The parameter q is therefore a measure of fluctuations of the parameters of the usual exponential distribution.
The nonextensitivity parameter $q$ occuring in some of the applications of Tsallis statistics (known also as index of the corresponding Lévy distribution) is shown to be given, in $q>1$ case, entirely by the fluctuations of the parameters of the usual exponential distribution.
We investigate the effect of nonextensive statistics as applied to the chemical fluctuations in high-energy nuclear collisions discussed recently using the event-by-event analysis of data. It turns out that very minuite nonextensitivity changes drastically the expected experimental output for the fluctuation measure. This results is in agreement with similar studies of nonextensity performed recently for the transverse momentum fluctuations in the same reactions.
Using simple space-time implementation of the random cascade model we investigate numerically influence of the possible fractal structure of the emitting source on Bose-Einstein correlations between identical particles. The results are then discussed in terms of the non-extensive Tsallis statistics.
Using simple space-time implementation of the random cascade model we investigate numerically a conjecture made some time ago which was joining the intermittent behaviour of spectra of emitted particles with the possible fractal structure of the emitting source. We demonstrate that such details are seen, as expected, in the Bose-Einstein correlations between identical particles. \\
We demonstrate on simple examples that oscillatory behaviour of moments of multiplicity distributions P(n) observed in e^+e^- annihilations, in hadronic pp collisions and in collisions on nuclei, p+A, is to a large extend caused by the experimental artifact of measuring only limited range of P(n). In particular we show that by applying a suitable universal cutt-off procedure to the measured P(n) one gets for reactions mentioned before oscillations of similar magnitude. The location of zeros of oscillations as a function of the rank of moments and their shapes remain, however, distinctively different for different types of reactions considered. This applies to some extend also to collisions of nuclei, which otherwise follow their own pattern of behaviour.
We present a phenomenological model which describes the formation of a Centauro fireball in nucleus-nucleus interactions in the upper atmosphere and at the LHC, and its decay to non-strange baryons and Strangelets. We describe the CASTOR detector for the ALICE experiment at the LHC. CASTOR will probe, in an event-by-event mode, the very forward, baryon-rich phase space 5.6 < η< 7.2 in 5.5 A TeV central Pb + Pb collisions. We present results of simulations for the response of the CASTOR calorimeter, and in particular to the traversal of Strangelets.
The physics motivation for a very forward detector for the ALICE heavy ion experiment at the CERN LHC is discussed. A phenomenological model describing the formation and decay of a Centauro fireball in nucleus-nucleus collisions is presented. The CASTOR detector which is aimed to measure the hadronic and photonic content of an interaction and to identify deeply penetrating objects in the very forward, baryon-rich phase space 5.6 < eta < 7.2 in an event-by-event mode is described. Results of simulations of the expected response of the calorimeter, and in particular to the passage of strangelets, are presented.
The inelasticity of hadron-carbon collisions for energies exceeding 100 TeV is estimated from the carbon-emulsion chamber data at Pamirs to be $ = 0.65\pm 0.08$. When combined with data on hadron-lead collisions taken at the same energy range it results in the $K\sim A^{0.086}$ mass number dependence of inelasticity. The evaluated partial inelasticity for secondary ($ν> 1$) interactions, $K_{ν>1} \simeq 0.2$, suggests that most of the energy is lost in the first interaction.
We argue that the so called long flying component (LFC) observed in some cosmic ray experiments are yet another manifestation of Lévy distributions (with index $q=1.3$), this time of the distribution observation probability of the depths of starting points of cascades. It means that LFC is governed by the so called long-tail Lévy-like anomalous superdiffusion, a phenomenon frequently encountered in Nature. Its connection with the so called Tsallis's statistics is also briefly discussed.