21 research outputs found
Application of the non-extensive statistical approach to high energy particle collisions
In high-energy collisions the number of the created particles is far less
than the thermodynamic limit, especially in small colliding systems (e.g.
proton-proton). Therefore final-state effects and fluctuations in the
one-particle energy distribution are appreciable. As a consequence the
characterization of identified hadron spectra with the Boltzmann\,--\,Gibbs
thermodynamical approach is insufficient. Instead particle spectra measured in
high-energy collisions can be described very well with Tsallis\,--\,Pareto
distributions, derived from non-extensive thermodynamics. Using the Tsallis
q-entropy formula, a generalization of the Boltzmann\,--\,Gibbs entropy, we
interpret the microscopical physics by analysing the Tsallis and
parameters. In this paper we give a quick overview on these parameters,
analyzing identified hadron spectra from recent years in a wide center of mass
energy range. We demonstrate that the fitted Tsallis-parameters show dependency
on this energy and on the particle species. Our findings are described well by
a QCD inspired evolution ansatz
Systematic analysis of the non-extensive statistical approach in high energy particle collisions-experiment vs. theory
The analysis of high-energy particle collisions is an excellent testbed for
the non-extensive statistical approach. In these reactions we are far from the
thermodynamical limit. In small colliding systems, such as electron-positron or
nuclear collisions, the number of particles is several orders of magnitude
smaller than the Avogadro number; therefore, finite-size and fluctuation
effects strongly influence the final-state one-particle energy distributions.
Due to the simple characterization, the description of the identified hadron
spectra with the Boltzmann-Gibbs thermodynamical approach is insufficient.
These spectra can be described very well with Tsallis-Pareto distributions
instead, derived from non-extensive thermodynamics. Using the -entropy
formula, we interpret the microscopic physics in terms of the Tsallis and
parameters. In this paper we give a view on these parameters, analyzing
identified hadron spectra from recent years in a wide center-of-mass energy
range. We demonstrate that the fitted Tsallis-parameters show dependency on the
center-of-mass energy and particle species (mass). Our findings are described
well by a QCD (Quantum Chromodynamics) inspired parton evolution ansatz. Based
on this comprehensive study, apart from the evolution, both mesonic and
baryonic components found to be non-extensive (), besides the mass ordered
hierarchy observed in the parameter . We also study and compare in details
the theory-obtained parameters for the case of PYTHIA8 Monte Carlo Generator,
perturbative QCD and quark coalescence models.Comment: 21 pages, 12 figures. This is an extended version of our paper at the
36th International Workshop on Bayesian Inference and Maximum Entropy Methods
in Science and Engineering (MaxEnt 2016), 10-15 July 2016, Ghent, Belgiu
Pion and Kaon Spectra from Distributed Mass Quark Matter
After discussing some hints for possible masses of quasiparticles in quark
matter on the basis of lattice equation of state, we present pion and kaon
transverse spectra obtained by recombining quarks with distributed mass and
thermal cut power-law momenta as well as fragmenting by NLO pQCD with intrinsic
{and nuclear} broadening.Comment: Talk given at SQM 200
Pions and kaons from stringy quark matter
Different hadron transverse momentum spectra are calculated in a
non-extensive statistical, quark-coalescence model. For the low-pT part a
gluonic string contribution is conjectured, its length distribution and
fractality are fitted to RHIC data.Comment: Contribution to SQM2008 (Beijing
Cooper-Frye Formula and Non-extensive Coalescence at RHIC Energy
Transverse spectra are calculated for various types of hadrons stemming from
Au Au collisions at GeV. We utilize a quark recombination model
based on generalized Boltzmann-Gibbs thermodynamics for local hadron production
at various break-up scenarios.Comment: 4 pages, 1 figur
Near-thermal equilibrium with Tsallis distributions in heavy ion collisions
Hadron yields in high energy heavy ion collisions have been fitted and
reproduced by thermal models using standard statistical distributions. These
models give insight into the freeze-out conditions at varying beam energies. In
this paper we investigate changes to this analysis when the statistical
distributions are replaced by Tsallis distributions for hadrons. We investigate
the appearance of near-thermal equilibrium state at SPS and RHIC energies. We
obtain better fits with smaller chi^2 for the same hadron data, as applied
earlier in the thermal fits for SPS energies but not for RHIC energies. This
result indicates that at RHIC energies the final state is very well described
by a single freeze-out temperature with very little room for fluctuations.Comment: 8 pages, 6 figure
Nonextensive statistical effects in the quark-gluon plasma formation at relativistic heavy-ion collisions energies
We investigate the relativistic equation of state of hadronic matter and
quark-gluon plasma at finite temperature and baryon density in the framework of
the non-extensive statistical mechanics, characterized by power-law quantum
distributions. We impose the Gibbs conditions on the global conservation of
baryon number, electric charge and strangeness number. For the hadronic phase,
we study an extended relativistic mean-field theoretical model with the
inclusion of strange particles (hyperons and mesons). For the quark sector, we
employ an extended MIT-Bag model. In this context we focus on the relevance of
non-extensive effects in the presence of strange matter.Comment: 12 pages, 5 figure
Consequences of temperature fluctuations in observables measured in high energy collisions
We review the consequences of intrinsic, nonstatistical temperature
fluctuations as seen in observables measured in high energy collisions. We do
this from the point of view of nonextensive statistics and Tsallis
distributions. Particular attention is paid to multiplicity fluctuations as a
first consequence of temperature fluctuations, to the equivalence of
temperature and volume fluctuations, to the generalized thermodynamic
fluctuations relations allowing us to compare fluctuations observed in
different parts of phase space, and to the problem of the relation between
Tsallis entropy and Tsallis distributions. We also discuss the possible
influence of conservation laws on these distributions and provide some examples
of how one can get them without considering temperature fluctuations.Comment: Revised version of the invited contribution to The European Physical
Journal A (Hadrons and Nuclei) topical issue about 'Relativistic Hydro- and
Thermodynamics in Nuclear Physics' guest eds. Tamas S. Biro, Gergely G.
Barnafoldi and Peter Va