184 research outputs found
Intriguing feature of multiplicity distributions
Multiplicity distributions, P(N), provide valuable information on the
mechanism of the production process. We argue that the observed P(N) contain
more information (located in the small N region) than expected and used so far.
We demonstrate that it can be retrieved by analysing specific combinations of
the experimentally measured values of P(N) which we call {it modified
combinants, Cj, and which show distinct oscillatory behavior, not observed in
the usual phenomenological forms of the P(N) used to fit data. We discuss the
possible sources of these oscillations and their impact on our understanding of
the multiparticle production mechanism.Comment: Invited talk presented at XLVIII International Symposium on
Multiparticle Dynamics (ISMD2018), 3 to 7 September 2018, Singapore; 10
pages, 6 figures. To be published in EPJ Web of Conference
Transverse momentum versus multiplicity fluctuations in high-energy nuclear collisions
We discuss recently measured event-by-event fluctuations of transverse
momentum and of multiplicity in relativistic heavy-ion collisions. It is shown
that the non-monotonic behavior of the p_T-fluctuations as a function of
collision centrality can be fully explained by the observed non-monotonic
multiplicity fluctuations. A possible mechanism responsible for the
multiplicity fluctuations is also considered.Comment: 5 pages, 3 figures, revised & extended, to appear in Phys. Rev.
Multiplicity fluctuations in the string clustering approach
We present our results on multiplicity fluctuations in the framework of the
string clustering approach. We compare our results --with and without
clustering formation-- with CERN SPS NA49 data. We find a non-monotonic
behaviour of these fluctuations as a function of the collision centrality,
which has the same origin as the observed fluctuations of transverse momentum:
the correlations between the produced particles due to the cluster formation.Comment: 16 pages, 4 figures, revte
Self-organized criticality in atmospheric cascades
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.Comment: gz-compressed .tar file containing LaTeX file and 5 PS files with
figures, 4 pages altogether (Nucl. Phys. B style, espcrc2.sty file attached)
Presented at XI International Symposium On Very High Energy Cosmic Ray
Interaction, Campinas, Brazil, July 17-21, 2000. To be published in Nucl.
Phys. B (Proc. Suppl.). Some typos correcte
Can Centauros or Chirons be the first observations of evaporating mini black holes?
We argue that the signals expected from the evaporation of mini black holes -
predicted in TeV-scale gravity models with large extra dimensions, and possibly
produced in ultra high energy collisions in the atmosphere - are quite similar
to the characteristics of the Centauro events, an old mystery of cosmic-ray
physics.Comment: 14 pages, LaTeX, one Table, uses rotate.sty and rotcapt.sty.
References added, typos corrected, footnotes moved into the tex
Locally anisotropic momentum distributions of hadrons at freeze-out in relativistic heavy-ion collisions
A spheroidal anisotropic local momentum distribution is implemented in the
statistical model of hadron production. We show that this form leads to exactly
the same ratios of hadronic abundances as the equilibrium distributions, if the
temperature is identified with a characteristic transverse-momentum scale.
Moreover, to a very good approximation the transverse-momentum spectra of
hadrons are the same for isotropic and anisotropic systems, provided the size
of the system at freeze-out is appropriately adjusted. We further show that
this invariance may be used to improve the agreement between the model and
experimental HBT results.Comment: 7 pages, 4 figure
Rapidity Spectra Analysis in Terms of Non Extensive Statistic Approach
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, nonextensivityComment: 4 pages, 4 figures, Presented at XII International Symposium on Very
High Energy Cosmic Ray Interactions, CERN, Switzerland, 15-20 July 200
Single-freeze-out model for ultra relativistic heavy-ion collisions at TeV and the LHC proton puzzle
The single-freeze-out model with parametrized hypersurface and flow geometry
is employed to analyze the transverse-momentum spectra of hadrons produced in
the Pb+Pb collisions at the collision energy of { TeV}
at the CERN Large Hadron Collider (LHC). With the notable exception for protons
and antiprotons, we find a very good agreement between the model results and
the data for the measured hadron species. The additional analysis of the HBT
radii of pions helps us to select, from several different types of freeze-out
studied in this work, the most realistic form of the freeze-out hypersurface.
We find that discrepancy ratio between the model and experiment for the
proton/antiproton spectra depends on , dropping from 2 in the soft region
to 1 around GeV.Comment: 9 pages, 10 figure
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