2,890 research outputs found
Density fluctuations and a first-order chiral phase transition in non-equilibrium
The thermodynamics of a first-order chiral phase transition is considered in
the presence of spinodal phase separation using the Nambu-Jona-Lasinio model in
the mean field approximation. We focus on the behavior of conserved charge
fluctuations. We show that in non-equilibrium the specific heat and charge
susceptibilities diverge as the system crosses the isothermal spinodal lines.Comment: 4 pages, 1 figure, to appear in the proceedings of Chiral07, November
13-16 2007, Osaka, Japa
Statistical Model Predictions for p+p and Pb+Pb Collisions at LHC
Particle production in p+p and central Pb+Pb collisions at LHC is discussed
in the context of the statistical thermal model. For heavy-ion collisions,
predictions of various particle ratios are presented. The sensitivity of
several ratios on the temperature and the baryon chemical potential is studied
in detail, and some of them, which are particularly appropriate to determine
the chemical freeze-out point experimentally, are indicated. Considering
elementary interactions on the other hand, we focus on strangeness production
and its possible suppression. Extrapolating the thermal parameters to LHC
energy, we present predictions of the statistical model for particle yields in
p+p collisions. We quantify the strangeness suppression by the correlation
volume parameter and discuss its influence on particle production. We propose
observables that can provide deeper insight into the mechanism of strangeness
production and suppression at LHC.Comment: 7 pages, 5 figures, conference contribution to "International school
of nuclear physics", Erice, Sicily, 16 - 24 September 2008; Progress in
Particle and Nuclear Physics, 2009, in pres
Thermodynamic limit and semi--intensive quantities
The properties of statistical ensembles with abelian charges close to the
thermodynamic limit are discussed. The finite volume corrections to the
probability distributions and particle density moments are calculated. Results
are obtained for statistical ensembles with both exact and average charge
conservation. A new class of variables (semi--intensive variables) which differ
in the thermodynamic limit depending on how charge conservation is implemented
in the system is introduced. The thermodynamic limit behavior of these
variables is calculated through the next to leading order finite volume
corrections to the corresponding probability density distributions.Comment: 11 pages, 2 figures In v2 figures are added and corresponding
editorial changes are done. Paper will be published in Journal of Physics
Remarks on combinatorial aspects of the KP Equation
Accepted for publication: AIP Conference Proceedings, 2nd International Workshop on Nonlinear and Modern Mathematical Physics, March 9-11, 2013. v2: Several clarifications made, references added, typos corrected; 16 pages, 1 figureAccepted for publication: AIP Conference Proceedings, 2nd International Workshop on Nonlinear and Modern Mathematical Physics, March 9-11, 2013. v2: Several clarifications made, references added, typos corrected; 16 pages, 1 figureAccepted for publication: AIP Conference Proceedings, 2nd International Workshop on Nonlinear and Modern Mathematical Physics, March 9-11, 2013. v2: Several clarifications made, references added, typos corrected; 16 pages, 1 figureAccepted for publication: AIP Conference Proceedings, 2nd International Workshop on Nonlinear and Modern Mathematical Physics, March 9-11, 2013. v2: Several clarifications made, references added, typos corrected; 16 pages, 1 figureNSF through grant DMS-0807705; AR is supported by the NSF under grant DMS-100438
Statistical Model Predictions for Pb-Pb Collisions at LHC
The systematics of Statistical Model parameters extracted from heavy-ion
collisions at lower energies are exploited to extrapolate in the LHC regime.
Predictions of various particle ratios are presented and particle production in
central Pb-Pb collisions at LHC is discussed in the context of the Statistical
Model. The sensitivity of several ratios on the temperature and the baryon
chemical potential is studied in detail, and some of them, which are
particularly appropriate to determine the chemical freeze-out point
experimentally, are indicated. The impact of feed-down contributions from
resonances, especially to light hadrons, is illustrated.Comment: 5 pages, 2 figures, 1 table, SQM 2006 conference proceedings,
accepted for publication in J. Phys.
Chemical Equilibrium in Collisions of Small Systems
The system-size dependence of particle production in heavy-ion collisions at
the top SPS energy is analyzed in terms of the statistical model. A systematic
comparison is made of two suppression mechanisms that quantify strange particle
yields in ultra-relativistic heavy-ion collisions: the canonical model with
strangeness correlation radius determined from the data and the model
formulated in the canonical ensemble using chemical off-equilibrium strangeness
suppression factor. The system-size dependence of the correlation radius and
the thermal parameters are obtained for p-p, C-C, Si-Si and Pb-Pb collisions at
sqrt(s_NN) = 17.3 AGeV. It is shown that on the basis of a consistent set of
data there is no clear difference between the two suppression patterns. In the
present study the strangeness correlation radius was found to exhibit a rather
weak dependence on the system size.Comment: 9 pages, 8 figures, submitted to Physical Review
Antimatter production in proton-proton and heavy-ion collisions at ultrarelativistic energies
One of the striking features of particle production at high beam energies is
the near equal abundance of matter and antimatter in the central rapidity
region. In this paper we study how this symmetry is reached as the beam energy
is increased. In particular, we quantify explicitly the energy dependence of
the approach to matter/antimatter symmetry in proton-proton and in heavy-ion
collisions. Expectations are presented also for the production of more complex
forms of antimatter like antihypernuclei.Comment: 7 pages, 5 figure
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