SHARE is a collection of programs designed for the statistical analysis of particle production in relativistic heavy-ion collisions. With the physical input of intensive statistical parameters, it generates the ratios of particle abundances. The program includes cascade decays of all confirmed resonances from the Particle Data Tables. The complete treatment of these resonances has been known to be a crucial factor behind the success of the statistical approach. An optional feature implemented is a Breit-Wigner type distribution for strong resonances. An interface for fitting the parameters of the model to the experimental data is provided.

We discuss the information that can be deduced from a measurement of particle (hyperon or vector meson) polarization in ultrarelativistic nuclear collisions. We describe the sensitivity of polarization to initial conditions, hydrodynamic evolution and mean free path, and find that the polarization observable is sensitive to all details and stages of the system's evolution. We suggest that an experimental investigation covering production plane and reaction plane polarizations, as well as the polarization of jet-associated particles in the plane defined by the jet and particle direction, can help in disentangling the factors contributing to this observable. Scans of polarization in energy and rapidity might also point to a change in the system's properties.Comment: In press, Phys.Rev.C. One new figure, text streamlined and edited, physics conclusions and reasoning not change

This writeup is a compilation of the predictions for the forthcoming Heavy Ion Program at the Large Hadron Collider, as presented at the CERN Theory Institute ‘Heavy Ion Collisions at the LHC—Last Call for Predictions’, held from 14th May to 10th June 2007.

We study the mass dependence for identified particle average transverse momentum and harmonic flow coefficients in proton-lead (p-Pb) collisions, recently measured at the LHC. The collective mechanism in the p-Pb system predicts a specific mass ordering in these observables: the growth of the average transverse momentum with the particle mass and a mass splitting of the elliptic flow coefficient, i.e., smaller differential elliptic flow of protons than pions for p(T)<2 GeV. This provides an opportunity to distinguish between the collective scenario and the mechanism based on the initial gluon dynamics in the evolution of the p-Pb system.

We explore the centrality dependence of the properties of the dense hadronic matter created in √ sNN = 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.

We introduce a new scenario for heavy ion collisions that could solve the lingering problems associated with the so-called HBT puzzle. We postulate that the system starts expansion as the perfect quark-gluon fluid but close to freeze-out it splits into clusters, due to a sharp rise of bulk viscosity in the vicinity of the hadronization transition. We then argue that the characteristic cluster size is determined by the viscosity coefficient and the expansion rate. Typically it is much smaller and at most weakly dependent of the total system volume (hence reaction energy and multiplicity). These clusters maintain the pre-existing outward-going flow, as a spray of droplets, but develop no flow of their own, and hadronize by evaporation. We provide an ansatz for converting the hydrodynamic output into clusters. 25.75.Dw, 25.75.Nq

We solve (3+1)-dimensional ideal hydrodynamical equations with source terms that describe punch-through and fully stopped jets in order to compare their final away-side angular correlations in a static medium. For fully stopped jets, the backreaction of the medium is described by a simple Bethe-Bloch-like model which leads to an explosive burst of energy and momentum (Bragg peak) close to the end of the jet's evolution through the medium. Surprisingly enough, we find that the medium's response and the corresponding away-side angular correlations are largely insensitive to whether the jet punches through or stops inside the medium. This result is also independent of whether momentum deposition is longitudinal (as generally occurs in pQCD energy loss models) or transverse (as the Bethe-Bloch formula implies). The existence of the diffusion wake is therefore shown to be universal to all scenarios where momentum as well as energy is deposited into the medium, which can readily be understood in ideal hydrodynamics through vorticity conservation. The particle yield coming from the strong forward moving diffusion wake that is formed in the wake of both punch-through and stopped jets largely overwhelms their weak Mach cone signal after freeze-out.

We study the production and the observability of Λ * (1520), K * 0 (892), and Σ * (1385), strange hadron resonances as function of the freeze-out conditions within the statistical model of hadron production. We obtain an estimate of how many decay products are rescattered in evolution towards thermal freeze-out following chemical freeze-out, and find that the resonance decay signal is strong enough to be detected. We show how a combined analysis of at least two resonances can be used to understand the chemical freeze-out temperature, and the time between chemical and thermal freeze-outs. PACS: 12.38.Mh, 24.10.Pa Hadronic particle signatures of the formation of QGP phase in relativistic heavy ion collisions are most sensitive when the dense hadron matter fireball breakup is sudden [1,2]. But final state particles could also emerge remembering relatively little about their primordial source, having been subject to rescattering in purely hadronic gas phase [3,4]. Which reaction picture applies can have decisive influence on our understanding of the underlying physics, and thus we propose here a systematic method to experimentally make a distinction.To address this question we consider strange hadron resonance abundances. At this time Λ(1520) has been observed in heavy ion reactions at SPS energies [5,6] following a suggestion that such a measurement was possible [7]. SPS [6] and RHIC experiments [8] report measurement of the K * 0 (892) signal, and RHIC has already measured both the K * 0 and the K * 0 . In the SPS case, the Λ(1520) abundance yield is about 2.5 times smaller than expectations based on the yield extrapolated from nucleon-nucleon reactions. This is to be compared with the enhancement by factor 2.5 of Λ-production in the same reaction in terms of the same comparison.A possible explanation for this effective suppression by a factor 5, or more, is that the decay products (π, Λ) produced at a high chemical freeze-out temperature T ≃ 175 MeV have rescattered and thus their momenta did not allow to reconstruct this state in an invariant mass analysis. However, the observation of a strong K * 0 -yield signal contradicts this point of view, since the K * 0 (892) decays faster (Γ K * 0 = 50.8 ± 0.9 MeV > Γ Λ * = 15.6 ± 1 MeV). Therefore, K * 0 (892) should be even more suppressed: a back of envelope calculation based on exponential population attenuation suggests that if the observable yield of Λ(1520) is reduced by factor 5, the observable yield of K * 0 (892) should be suppressed by a factor 10.Another explanation is that the chemical freeze-out temperature which governs the production of these resonances in a thermal model is considerably lower, and hence rescattering of decay products is less significant. This is a point of view arising from a recent analysis of the hadronization process [1].We explore the production, and the suppression of the observability of these resonances(K * 0 (892), Λ(1520)), and also explore the (more difficult) measurement of the Σ * (1385) state as a further way of distingui...