Strangeness in QGP: Hadronization Pressure

We review strangeness as signature of quark gluon plasma (QGP) and the hadronization process of a QGP fireball formed in relativistic heavy-ion collisions in the entire range of today accessible reaction energies. We discuss energy dependence of the statistical hadronization parameters within the context of fast QGP hadronization. We find that QGP breakup occurs for all energies at the universal hadronization pressure $P = 80\pm 3\,\mathrm{MeV/fm}^3$.Comment: 14 pages, one picture, 10 figures, Talk presented at the XXXI Max Born Symposium and HIC for FAIR Workshop "Three Days of Critical Behavior in Hot and Dense QCD", Wroclaw, Poland, June~14-16, 2013. Acta Physica Polonica B: Conference Series in pres

Strangeness Production in Au--Au collisions at sNN=62.4\sqrt{s_{NN}}=62.4 GeV

We obtain strangeness production as function of centrality in a statistical hadronization model analysis of all experimental hadron production data in Au--Au collisions at \sqrt{s_{NN}}=62.4\GeV. Our analysis describes successfully the yield of strange and multi-strange hadrons recently published. We explore condition of hadronization as a function of centrality and find universality for the case of chemical non-equilibrium in the hadron phase space corresponding to quark--gluon plasma (QGP) in chemical equilibrium.Comment: 6 pages, 2 figures, proceedings for SQM 2011 conferenc

QCD phase transition studied by means of hadron production

This is a brief review of our work describing the hadronization process of a QGP fireball formed in relativistic heavy-ion collisions. We introduce the SHARE method of analysis of hadron multiplicities. Using this tool we describe in consistent continuos manner the yield of all hadrons produced in the available range of reaction energies and centralities. The properties of the fireball final state can be understood by considering all primary hadronic particles. The dense hadron fireball created at SPS, RHIC, and LHC shows that the final state is differentiated solely by: i) volume changes; and ii) flavor (strangeness, charm) content. Conversely, emerging particles add up to create universal hadronization pressure $P = 80 \pm 3$ MeV/fm$^3$ for all considered collision systems. The relative strangeness to entropy content of a large fireball is found to be that of quark-gluon plasma degrees of freedom near the chemical QGP equilibrium. This 'Universal Hadronization' condition common to SPS, RHIC, and LHC agrees with the proposed reaction picture of a direct QGP fireball evaporation into free-streaming hadrons.Comment: 11 pages, many figures; Presented in Wroclaw at the February 2014 MB32-Symposium honoring Ludwik Turk

Hadron production and QGP Hadronization in Pb--Pb collisions at sNN=2.76\sqrt{s_{NN}}=2.76 TeV

We show that all central rapidity hadron yields measured in Pb--Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV are well described by the chemical non-equilibrium statistical hadronization model (SHM), where the chemically equilibrated QGP source breaks up directly into hadrons. SHM parameters are obtained as a function of centrality of colliding ions, and we compare CERN Large Hadron Collider (LHC) with Brookhaven National Laboratory Relativistic Heavy Ion Collider (RHIC) results. We predict yields of unobserved hadrons and address anti-matter production. The physical properties of the quark--gluon plasma fireball particle source show universality of hadronization conditions at LHC and RHIC.Comment: 22 pages, 16 figures, 6 table

CHARM and Strangeness in Quark-Gluon Plasma Hadronization

This dissertation presents a theoretical study of soft hadron production in relativistic heavy-ion collisions. The aim is to explore the principles governing the hadronization of the expanding quark-gluon plasma (QGP) fireball, and to understand its properties. Strange hadron production and strangeness abundance in the QGP help us to look before the instant of hadronization. Consideration of entropy and charm production further enhances the reach back in time to the first instances of the heavy ion collision. Much of the ongoing effort is to demonstrate the validity of a QGP hadronization model which describes the particle production data accurately and thus allows us to carry out the above research program. We perform a centrality dependent study of multistrange hadrons from Au-Au collisions at √SNN = 62.4 GeV, data obtained at the Relativistic Heavy Ion Collider (RHIC). We show that the statistical hadronization model (SHM) well describes particle production. For all centralities, the particle production conditions are compatible with the earlier proposed critical hadronization pressure suggesting a set of universal hadronization conditions of QGP. Heavy-ion collisions at the Large Hadron Collider (LHC) present a new challenge for SHM in describing particle production at TeV energy scales. The chemical non-equilibrium model gives a good description of the hadron production in Pb-Pb collisions at √SNN = 2.76 TeV consistently as a function of centrality. Moreover, the model parameters, such as chemical freeze-out temperature, assume expected values suggested by results from previous studies at lower energies. The quark-gluon plasma fireball hadronizes at the same universal hadronization conditions, that is a common critical pressure, entropy and energy density. At LHC energies, a significant amount of charm is expected to be produced. It is therefore crucial to incorporate charm into the present description of particle production. We present a new tool, an upgraded SHARE with CHARM program, that quantifies the effect of charm on the yield of lighter hadrons and physical properties of the hadronizing fireball. In addition to light flavors (u,d,s), SHARE with CHARM describes charm hadron production and decays of charm hadrons. According to present experimental results, charm decays mainly affect the yields of multistrange particles. This dissertation begins with an introduction to the particle production in heavy-ion collisions and SHM framework, followed by a summary of results that are either published or submitted to peer-reviewed journals and others which are published as conference proceedings. Reprints of the publications are attached to the dissertation as appendices. Each appendix is prefaced with a short summary of presented results, and my contribution to these works is described

The OZI Rule in Meson Decay

This presentation nequires the knowledge about meson decayThis Demonstration shows the OZI rule applied in the decay of one meson into two. This rule determines which strong processes are preferred and which are allowed but strongly suppressedComponente Curricular::Educação Superior::Ciências Exatas e da Terra::Físic