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

Statistical Model Predictions for Particle Ratios at sqrt(s_NN) = 5.5 TeV

Particle production in central Pb-Pb collisions at LHC is discussed in the context of the Statistical Model. Predictions of various particle ratios are presented with the corresponding choice of model parameters made according to the systematics extracted from heavy-ion collisions at lower energies. 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. We show that the anti-p / p ratio is most suitable to determine the baryon chemical potential while the Omega / K and Omega / pi ratios are best to determine the temperature at chemical freeze-out.Comment: Submitted to Phys. Rev. C, 7 pages, 4 figure

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

Particle production in p-p collisions and prediction for LHC energy

We analyze recent data on particle production yields obtained in p-p collisions at SPS and RHIC energies within the statistical model. We apply the model formulated in the canonical ensemble and focus on strange particle production. We introduce different methods to account for strangeness suppression effects and discuss their phenomenological verification. We show that at RHIC the midrapidity data on strange and multistrange particle multiplicity can be successfully described by the canonical statistical model with and without an extra suppression effects. On the other hand, SPS data integrated over the full phase-space require an additional strangeness suppression factor that is beyond the conventional canonical model. This factor is quantified by the strangeness saturation parameter or strangeness correlation volume. Extrapolating all relevant thermal parameters from SPS and RHIC to LHC energy we present predictions of the statistical model for particle yields in p-p collisions at sqrt(s) = 14TeV. We discuss the role and the influence of a strangeness correlation volume on particle production in p-p collisions at LHC.Comment: 6 pages, 6 figures, 4 tables, submitted to Phys. Rev.

Particle production in p-p collisions at sqrt(s) = 17 GeV within the statistical model

A thermal-model analysis of particle production of p-p collisions at sqrt(s) = 17 GeV using the latest available data is presented. The sensitivity of model parameters on data selections and model assumptions is studied. The system-size dependence of thermal parameters and recent differences in the statistical model analysis of p-p collisions at the super proton synchrotron (SPS) are discussed. It is shown that the temperature and strangeness undersaturation factor depend strongly on kaon yields which at present are still not well known experimentally. It is conclude, that within the presently available data at the SPS it is rather unlikely that the temperature in p-p collisions exceeds significantly that expected in central collisions of heavy ions at the same energy.Comment: 6 pages, 3 figures, submitted to Phys. Rev.

Production of nuclei and antinuclei in pp and Pb-Pb collisions with ALICE at the LHC

We present first results on the production of nuclei and antinuclei such as (anti)deuterons, (anti)tritons, (anti)3He and (anti)4He in pp collisions at \s = 7 TeV and Pb-Pb collisions at \sNN = 2.76 TeV. These particles are identified using their energy loss (dE/dx) information in the Time Projection Chamber of the ALICE experiment. The Inner Tracking System gives a precise determination of the event vertex, by which primary and secondary particles are separated. The high statistics of over 360 million events for pp and 16 million events for Pb-Pb collisions give a significant number of light nuclei and antinuclei (Pb-Pb collisions: \sim30,000 anti-deuterons($\bar{d}$) and \sim4 anti-alpha($\bar{^4He}$)). The predictions of various particle ratios from the THERMUS model is also discussed.Comment: 4 pages, 5 figures, parallel talk at Quark Matter 2011, May 23rd-28th 2011, Annecy, Franc

Particle Production in p-p and Heavy Ion Collisions at Ultrarelativistic Energies

Recent results related to the chemical equilibration of hadrons in the final state of p-p and heavy ion collisions are reviewed.Comment: 13 pages, 11 figures, Kruger2010: Workshop on Discovery Physics at the LHC, December 5 - 10 2010 Kruger National Park, South Afric

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