arXiv subjects
Publications and source records attributed to Jean Letessier.
We extend the SHM analysis of hadron production results showing here consistency with the increased experimental data set, stability of the fit with regard to inclusion of finite resonance widths and 2-star hyperon resonances. We present new results on strangeness yield as a function of centrality and present their interpretation in terms of QGP inspired model of strangeness abundance in the hadronizing fireball.
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.
The properties of the quark and hadron Universe are explored. Kinetic theory considerations are presented proving that hadron abundances after phase transformation from quarks to hadrons remain intact till abundances of hadrons become irrelevant. The hadronization process and the evolution of hadron yields is described in detail.
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.
We obtain within the statistical hadronization model the hadron yields $dh/dy$ in heavy ion reactions at $\sqrt{s_{NN}} = 2.76$ TeV. We discuss the dependence both on hadronization temperature $T$, and on critical hadronization pressure $P$. We consider observables distinguishing the hadronization models and conditions.
We study multistrange hadrons produced in NA49 and STAR experiments at center of mass energies varying from \sqrt{s_{NN}} = 7.61 GeV to 200 GeV. We show that the yields of Ξ, Ξ-bar and ϕ can help to constrain the physical conditions present in the hot dense fireball source of these multistrange hadrons created in heavy ion collision. We address the question of chemical equilibrium of individual quark flavors before and after hadronization and offer a few predictions for LHC.
We discuss the bulk properties of QGP produced at RHIC obtained at time of hadronization. We argue that hadronization of quark--gluon plasma occurs at a critical pressure of 82 MeV/fm3, obtained for SPS energy range.
We present a detailed analysis of the NA49 experimental particle yield results, and discuss the physical properties of the particle source. We explain in depth how our analysis differs from the work of other groups, what advance this implies in terms of our understanding, and what new physics about the deconfined particle source this allows us to recognize. We answer several frequently asked questions, presenting a transcript of a discussion regarding our data analysis. We show that the final NA49 data at 40, 80, 158 AGeV lead to a remarkably constant extensive thermal chemical-freeze-out properties of the fireball. We discuss briefly the importance of thermal hadronization pressure.
We study soft hadron production in relativistic heavy ion collisions in a wide range of reaction energy, 4.8 GeV sqrt{s_NN} \ge 200 GeV, we use continuity of particle yields and statistical parameters to predict the hadron production at sqrt{s_NN}=62.4 GeV, and obtain total yields of hadrons at sqrt{s_NN}=130 GeV. We consider, in depth, the pattern we uncover within the hadronization condition, and discuss possible mechanisms associated with the identified rapid change in system properties at sqrt{s_NN ^cr}. We propose that the chemically over-saturated 2+1 flavor hadron matter system undergoes a 1st order phase transition.
We explore entropy and strangeness as signature of QGP for top AGS energy and the energy scan at SPS. We find that the hadronization dynamics changes between 20 and 30 $A$ GeV projectile energy. The high energy results are consistent with QGP.
We study production of strangeness in the hot QGP fireball in conditions achieved at LHC, and use these results to obtain soft (strange) hadron multiplicities. We compare the chemical equilibrium and non-equilibrium conditions and identify characteristic experimental observables.
We study, in the dynamically evolving QGP fireball formed in relativistic heavy ion collisions at RHIC and LHC, the growth of strangeness yield toward and beyond the chemical equilibrium. We account for the contribution of the direct strangeness production and evaluate the thermal-QCD strangeness production mechanisms. The specific yield of strangeness per entropy, s/S, is the primary target variable. We explore the effect of collision impact parameter, i.e., fireball size, on kinetic strangeness chemical equilibration in QGP. Insights gained in study the RHIC data with regard to the dynamics of the fireball are applied to the study strangeness production at the LHC. We use these results and consider the strange hadron relative particle yields at RHIC and LHC in a systematic fashion. We consider both the dependence on s/S and directly participant number dependence.
Is the new state of matter formed in relativistic heavy ion collisions the deconfined quark--gluon plasma? We survey the status of several strange hadron observables and discuss how these measurement help understand the dense hadronic matter.
We discuss how the dynamics of the evolving hot fireball of quark--gluon matter impacts phase transition between the deconfined and confined state of matter. The rapid expansion of the fireball of deconfined matter created in heavy ion collisions facilitates formation of an over-saturated strange quark phase space. The related excess abundance of strangeness is compensating the suppression of this semi-heavy quark yield by its quark mass. In addition, the dynamical expansion of colored quanta pushes against the vacuum structure, with a resulting supercooling of the transition temperature. We address the status of the search for the phase boundary as function of reaction energy and collision centrality and show evidence for a change in reaction mechanism at sufficiently low energies. The phase diagram derived from the study of hadron production conditions shows two boundaries, one corresponding to the expected transition between confined and deconfined matter, with a downward temperature shift, and the other a high quark density hadronization which appears to involve heavy effective quarks, at relatively large temperatures.
High precision soft hadron abundance data produced in relativistic nuclear collisions at LHC at $\sqrt{s_{\rm NN}}\le 5500$ GeV will become available beginning in 2007/8. We explore, within the statistical hadronization model, how these results can help us understand the properties of the deconfined quark--gluon phase at its breakup. We make assumptions about the physical properties of the fireball and obtain particle production predictions. Then, we develop a strategy to measure parameters of interest, such as strangeness occupancy $γ_s$, chemical potentials $μ_{\rm B}$ and $μ_{\rm S}$.
We evaluate strangeness produced in Au--Au interactions at $\sqrt{s_{\rm NN}}=200$ GeV, as function of reaction participant number $A$, and obtain the relative strange quark content at hadronization. Strange baryon and antibaryon rapidity density yields are studied, relative to, and as function of, participant number, and produced hadron yields.
We explore the centrality dependence of properties of the dense hadronic matter created in \sqrt{s_{NN}}=200 GeV Au--Au collisions at RHIC. Using the statistical hadronization model we fit particle yields known for 11 centrality bins. We present the resulting model parameters, rapidity yields of physical quantities and the physical properties of bulk matter at hadronization as function of centrality. We discuss the production of strangeness and entropy.
Strangeness flavor yield s and the entropy yield S are the observables of the deconfined quark-gluon state of matter which can be studied in the entire available experimental energy range at AGS, SPS, RHIC, and, in near future, at the LHC energy range. We present here a comprehensive analysis of strange, soft hadron production as function of energy and reaction volume. We discuss the physical properties of the final state and argue how evidence about the primordial QGP emerges.