arXiv subjects

Grzegorz Wilk

Publications and source records attributed to Grzegorz Wilk.

At least 19 recordsLinked to original sources

arXiv2025

A harmonic oscillator in nonadditive statistics and a novel transverse momentum spectrum in high-energy collisions

It is widely observed that particles produced in high-energy collisions follow a power-law distribution. One such power-law distribution used extensively in the phenomenological studies owes its origin to nonadditive statistics proposed by C. Tsallis. In this article, we derive a novel nonadditive generalization of the conventional Bose-Einstein distribution using a single-mode harmonic oscillator. The approach taken in this paper eliminates the need of a regularization procedure proposed in previous works. We observe that the spectra of the bosonic particles like the pions and kaons produced in high-energy collisions are well-described by the nonadditive bosonic distribution derived in this paper.

hep-ph↗

arXiv2023

Geometric Poisson distribution of photons produced in the ultrarelativistic hadronic collisions

We show that the multiplicity distribution of photons produced with enhanced void probability in inelastic proton-proton collisions at $\sqrt{s} =$ 900 GeV, 2.76 TeV, and 7 TeV, measured at forward rapidities by the ALICE experiment at LHC, can be described by the geometric Poisson distribution. The traditionally used negative binomial distribution fails to reproduce the enhanced void probability and the shape of the modified combinants simultaneously. Our findings are relevant for the theoretical modeling of photon production processes in high-energy hadronic collisions.

hep-ph↗

arXiv2023

Signatures of deuteron synthesis on the modified combinants in nuclear collisions

The mechanism of deuteron production in heavy-ion collisions is shown to have a significant impact on the shape of the modified combinants of their multiplicity distribution. In light of this observation, an experimental study is proposed to tackle the long-standing problem of nuclei synthesis in hadronic and nuclear collisions. The proposed approach has the potential to provide stringent constraints on the models of deuteron synthesis.

nucl-th↗

arXiv2022

Sub-Poissonian multiplicity distributions in jets produced in hadron collisions

In this work we show that the proper analysis and interpretation of the experimental data on the multiplicity distributions of charged particles produced in jets measured in the ATLAS experiment at the LHC indicates their sub-Poissonian nature. We also show how, by using the recurrent relations and combinants of these distributions, one can obtain new information contained in them and otherwise unavailable, which may broaden our knowledge of the particle production mechanism.

hep-ph↗

arXiv2021

Beyond the relaxation time approximation

The relaxation time approximation (RTA) is a well known method of describing the time evolution of a statistical ensemble by linking distributions of the variables of interest at different stages of their temporal evolution. We show that if all the distributions occurring in the RTA have the same functional form of a quasi-power Tsallis distribution the time evolution of which depends on the time evolution of its control parameter, nonextensivity $q(t)$, then it is more convenient to consider only the time evolution of this control parameter.

cond-mat.stat-mech↗

arXiv2021

Relaxation and correlation times of nonequilibrium multiparticle systems

Relaxation and correlation times are two parameters used frequently in approximate descriptions of the time development of hadronizing system from some initial state towards distributions observed experimentally. Chosen to reproduce the experimental results they represent, in a sense, the history of the hadronization process. The analysis of their changes with energy is the subject of our work.

hep-ph↗

arXiv2021

Counting distributions from the perspective of combinants

We present a comprehensive insight into counting distributions from the perspective of the combinants extracted from them. In particular, we focus on cases where these combinants exhibit oscillatory behavior that can provide an invaluable new source of information about the dynamics of the process under study. We show that such behavior can be described only by specific combinations of compound distributions based on the Binomial Distribution and provide their analytical forms which can be used in further investigations and which can be helpful in the analysis of all other types of counting distributions.

hep-ph↗

arXiv2019

Dynamical nonextensivity or nonextensive dynamics?

Dense matter is usually described using some kind of mean field theory (MFT) model based on Boltzmann-Gibbs (BG) extensive statistics. However, in many cases the conditions justifying the use of BG statistics are not fulfilled because the systems considered are explicitly nonextensive. In such cases one either enriches the original MFT by adding some dynamical elements violating extensivity (like, for example, long range correlations or intrinsic fluctuations), or one replaces the BG statistics by its nonextensive counterpart characterized by some nonextensivity parameter q 1 (for q -> 1 one returns to the extensive situation). In this work, using a simple quasi-particle description of dense matter (with interaction modelled by effective fugacities, z) we discuss the mutual interplay of non-extensiveness and dynamics (i.e., q and z).

hep-ph↗

arXiv2019

Intriguing properties of multiplicity distributions

Multiplicity distributions exhibit, after closer inspection, peculiarly enhanced void probability and oscillatory behavior of the modified combinants. We discuss the possible sources of these oscillations and their impact on our understanding of the multiparticle production mechanism. Theoretical understanding of both phenomena within the class of compound distributions is presented.

hep-ph↗

arXiv2019

Nonextensive quasiparticle description of QCD matter

The dynamics of QCD matter is often described using effective mean field (MF) models based on Boltzmann-Gibbs (BG) extensive statistics. However, such matter is normally produced in small packets and in violent collisions where the usual conditions justifying the use of BG statistics are not fulfilled and the systems produced are not extensive. This can be accounted for either by enriching the original dynamics or by replacing the BG statistics by its nonextensive counterpart described by a nonextensivity parameter $q\neq 1$ (for $q \to 1$ one returns to the extensive situation). In this work we investigate the interplay between the effects of dynamics and nonextensivity. Since the complexity of the nonextensive MF models prevents their simple visualization, we instead use some simple quasi-particle description of QCD matter in which the interaction is modelled phenomenologically by some effective fugacities, $z$. Embedding such a model in a nonextensive environment allows for a well-defined separation of the dynamics (represented by $z$) and the nonextensivity (represented by $q$) and a better understanding of their relationship.

hep-ph↗

arXiv2018

Some intriguing aspects of multiparticle production processes

Multiparticle production processes provide valuable information about the mechanism of the conversion of the initial energy of projectiles into a number of secondaries by measuring their multiplicity distributions and their distributions in phase space. They therefore serve as a reference point for more involved measurements. Distributions in phase space are usually investigated using the statistical approach, very successful in general but failing in cases of small colliding systems, small multiplicities, and at the edges of the allowed phase space, in which cases the underlying dynamical effects competing with the statistical distributions take over. We discuss an alternative approach, which applies to the whole phase space without detailed knowledge of dynamics. It is based on a modification of the usual statistics by generalizing it to a superstatistical form. We stress particularly the scaling and self-similar properties of such an approach manifesting themselves as the phenomena of the log-periodic oscillations and oscillations of temperature caused by sound waves in hadronic matter. Concerning the multiplicity distributions we discuss in detail the phenomenon of the oscillatory behaviour of the modified combinants apparently observed in experimental data.

hep-ph↗

arXiv2017

Oscillations in multiparticle production processes

We discuss two examples of oscillations apparently hidden in some experimental results for high energy multiparticle production processes: (i) - the log-periodic oscillatory pattern decorating the power-like Tsallis distributions of transverse momenta, (ii) - the oscillations of the modified combinants obtained from the measured multiplicity distributions. We show that in both cases these phenomena can provide new insight into the dynamics of these processes.

hep-ph↗

arXiv2017

Sound waves in hadronic matter

We argue that recent high energy CERN LHC experiments on transverse momenta distributions of produced particles provide us new, so far unnoticed and not fully appreciated, information on the underlying production processes. To this end we concentrate on the small (but persistent) log-periodic oscillations decorating the observed $p_T$ spectra and visible in the measured ratios $R = σ_{data}\left( p_T\right)/σ_{fit}\left( p_T\right)$. Because such spectra are described by quasi-power-like formulas characterised by two parameters: the power index $n$ and scale parameter $T$ (usually identified with temperature $T$), the observed log-periodic behaviour of the ratios $R$ can originate either from suitable modifications of $n$ or $T$ (or both, but such a possibility is not discussed). In the first case $n$ becomes a complex number and this can be related to scale invariance in the system, in the second the scale parameter $T$ exhibits itself log-periodic oscillations which can be interpreted as the presence of some kind of sound waves forming in the collision system during the collision process, the wave number of which has a so-called self similar solution of the second kind. Because the first case was already widely discussed we concentrate on the second one and on its possible experimental consequences.

hep-ph↗

arXiv2017

Temperature oscillations and sound waves in hadronic matter

Recent high energy CERN LHC experiments on transverse momenta distributions of produced particles seem to show the existence of some (small but persistent) log-periodic oscillation in the ratios $R = σ_{data}\left( p_T\right)/σ_{fit}\left( p_T\right)$. We argue that they can provide us with so far unnoticed information on the production process, which can be interpreted as the presence of some kind of sound waves formed during the collision process in the bulk of the produced high density matter.

hep-ph↗

arXiv2016

How to retrieve additional information from the multiplicity distributions

Multiplicity distributions $P(N)$ measured in multiparticle production processes are most frequently described by the Negative Binomial Distribution (NBD). However, with increasing collision energy some systematic discrepancies become more and more apparent. They are usually attributed to the possible multi-source structure of the production process and described using a multi-NBD form of the multiplicity distribution. We investigate the possibility of keeping a single NBD but with its parameters depending on the multiplicity $N$. This is done by modifying the widely known clan model of particle production leading to the NBD form of $P(N)$. This is then confronted with the approach based on the so-called cascade-stochastic formalism which is based on different types of recurrence relations defining $P(N)$. We demonstrate that a combination of both approaches allows the retrieval of additional valuable information from the multiplicity distributions, namely the oscillatory behavior of the counting statistics apparently visible in the high energy data.

hep-ph↗

arXiv2016

Muon bundles from extensive air showers

In this talk we present a possible explanation of the presence of high muon multiplicity events registered recenty by CERN ALICE experiment in its dedicated cosmic ray run.

hep-ph↗

arXiv2016

Oscillations in counting statistics

The very large transverse momenta and large multiplicities available in present LHC experiments on pp collisions allow a much closer look at the corresponding distributions. Some time ago we discussed a possible physical meaning of apparent log-periodic oscillations showing up in p_T distributions (suggesting that the exponent of the observed power-like behavior is complex). In this talk we concentrate on another example of oscillations, this time connected with multiplicity distributions P(N). We argue that some combinations of the experimentally measured values of P(N) (satisfying the recurrence relations used in the description of cascade-stochastic processes in quantum optics) exhibit distinct oscillatory behavior, not observed in the usual Negative Binomial Distributions used to fit data. These oscillations provide yet another example of oscillations seen in counting statistics in many different, apparently very disparate branches of physics further demonstrating the universality of this phenomenon.

hep-ph↗

arXiv2016

Nonextensive Nambu Jona-Lasinio model of QCD matter revisited

We present a revisited version of the nonextensive QCD-based Nambu - Jona-Lasinio (NJL) model describing the behavior of strongly interacting matter proposed by us some time ago. As before, it is based on the nonextensive generalization of the Boltzmann-Gibbs (BG) statistical mechanics used in the NJL model to its nonextensive version based on Tsallis statistics, but this time it fulfils the basic requirements of thermodynamical consistency. Different ways in which this can be done, connected with different possible choices of the form of the corresponding nonextensive entropies, are presented and discussed in detail. The corresponding results are compared, discussed and confronted with previous findings.

nucl-th↗