High Density QCD Physics with Heavy Ions in CMS

The heavy ion program of the CMS experiment will examine the QCD matter under extreme conditions, through the study of global observables and specific probes.Comment: 4 pages, Presented at Moriond QCD and Hadronic interactions, La Thuile, Italy, 23 March 200

Recent NA49 results on Pb+Pb collisions at CERN SPS

In the spirit of establishing a fair reference for nucleus-nucleus collisions, results on stopping and baryon transfer, correlations of the p+p interaction and their consequences are shown. In the discussion of new results from nucleus-nucleus collisions the emphasis is on strange meson and baryon production at different energies - for the first time at 40 GeV A - with the study of light nuclei.Comment: 9 pages, 21 figures, proceedings of ISMD200

Soft physics capabilities of CMS in p-p and Pb-Pb

The CMS experiment will provide good quality measurements of yields and spectra of identified charged and neutral particles, both in p-p and heavy-ion collisions, thus contributing to the study of soft hadronic physics at the LHC energies.Comment: 4 pages, presented at the Quark Matter 2008 Conference, Jaipur, India, 4-10 February 200

CMS: minimum bias studies

The early data from LHC will allow the first look at minimum bias p-p collisions initially at the center-of-mass energies of 10 and later 14 TeV. The plans of the CMS collaboration to measure cross sections and differential yields of charged particles (unidentified or identified) and neutrals produced in inelastic p-p collisions at 14 TeV are presented. The tracking of charged particles will be possible down to about 100 MeV/c, with good efficiency and negligible fake rate. The yield of charged kaons and protons can be extracted for total momenta below 0.8 and 1.5 GeV/c, respectively. Comparisons of the results to theoretical models are also discussed

Reconstruction of Hadronization Stage in Pb+Pb Collisions at 158A GeV/c

Recent data on hadron multiplicities in central Pb+Pb collisions at 158A GeV/c at mid-rapidity are analyzed within the concept of chemical freeze-out. A non-uniformity of the baryon chemical potential along the beam axis is taken into account. An approximate analytical solution of the hydrodynamic equations for a chemically frozen Boltzmann-like gas is found. The Cauchy conditions for hydrodynamic evolution of the hadron resonance gas are fixed at the thermal freeze-out hypersurface from analysis of one-particle momentum spectra and HBT correlations. The proper time of chemical freeze-out and physical conditions at the hadronization stage, such as energy density and averaged transverse velocity, are found.Comment: 21 pages including 3 figures, RevTex, semi-relativistic solution of hydrodynamics was used, submitted to Nucl. Phys.

Event-by-event fluctuations of the kaon to pion ratio in central Pb+Pb collisions at 158 GeV per Nucleon

We present the first measurement of fluctuations from event to event in the production of strange particles in collisions of heavy nuclei. The ratio of charged kaons to charged pions is determined for individual central Pb+Pb collisions. After accounting for the fluctuations due to detector resolution and finite number statistics we derive an upper limit on genuine non-statistical fluctuations, perhaps related to a first or second order QCD phase transition. Such fluctuations are shown to be very small.Comment: 4 pages, 2 figure

New results from NA49

Recent results of the NA49 experiment are presented. These cover first results on pion and kaon production, HBT, and charge fluctuations from Pb+Pb reactions at 40A GeV and their comparison to 158A GeV beam energy. Furthermore a study on baryon number transfer in p+p, centrality selected p+Pb and Pb+Pb collisions at 158A GeV and new results on the system size dependence of kaon yields, including C+C and Si+Si data, are presented. Additionally, a first result on $\Lambda$ $\Lambda$ correlations is shown