Diffraction measurements at the LHC

Proton-proton collisions at the LHC can be classified as elastic, non-diffractive, and diffractive. In this paper we discuss various measurements of these above processes at various LHC experiments. We report about the total proton-proton cross-section measurements, about the analysis of diffractive events and also about the pseudorapidity distribution in inelastic events.Comment: 9 pages, 5 figures. Proceedings of the XLIII International Symposium on Multiparticle Dynamic

Systematics of Identified Hadron Spectra at PHENIX

Mid-rapidity transverse momentum distributions for $\pi^\pm$, $K^\pm$, p and \pbar are measured by the PHENIX experiment at RHIC in Au+Au, d+Au and p+p collisions at \ssnn=200GeV up to ~2--4GeV. Also particle ratios of $\pi^{-}/\pi^{+}$, $K^{-}/K^{+}$, \pbar/p, $p/\pi$ and \pbar/\pi are measured, as well as the nuclear modification factor, all as a function of \pt and in every of the above collision systems. Finally, the measured p+p and Au+Au spectra are compared to the Buda-Lund hydro model.Comment: Proceedings of the 20th Lake Louise Winter Institute, 20-26 February 2005. To appear in World Scientifi

Anomalous diffusion of pions at RHIC

After pointing out the difference between normal and anomalous diffusion, we consider a hadron resonance cascade (HRC) model simulation for particle emission at RHIC and point out, that rescattering in an expanding hadron resonance gas leads to a heavy tail in the source distribution. The results are compared to recent PHENIX measurements of the tail of the particle emitting source in Au+Au collisions at RHIC. In this context, we show, how can one distinguish experimentally the anomalous diffusion of hadrons from a second order QCD phase transition.Comment: 12 pages, 26 figures. Presented by T. Csorgo at the 2nd Workshop on Particle Femtoscopy and Correlations - WPCF in Sao Paulo, sept 2006. Brazilian Journal of Physics in press, minor misprints fixe

Similar final states from different initial states using new exact solutions of relativistic hydrodynamics

We present exact, analytic and simple solutions of relativistic perfect fluid hydrodynamics. The solutions allow us to calculate the rapidity distribution of the particles produced at the freeze-out, and fit them to the measured rapidity distribution data. We also give an advanced estimation of the energy density reached in heavy ion collisions, and an improved estimation of the life-time of the reaction.Comment: This article is a written-up version of the talk given by M. Csanad on the Zimanyi '75 Memorial Workshop held in Budapest, June 200

A New Family of Simple Solutions of Perfect Fluid Hydrodynamics

A new class of accelerating, exact and explicit solutions of relativistic hydrodynamics is found - more than 50 years after the previous similar result, the Landau-Khalatnikov solution. Surprisingly, the new solutions have a simple form, that generalizes the renowned, but accelerationless, Hwa-Bjorken solution. These new solutions take into account the work done by the fluid elements on each other, and work not only in one temporal and one spatial dimensions, but also in arbitrary number of spatial dimensions. They are applied here for an advanced estimation of initial energy density and life-time of the reaction in ultra-relativistic heavy ion collisions.Comment: 10 pages, 5 figures. EOS is generalized to include a bag constant, clarity of the presentation is improved and a misprinted label is corrected in Fig. 2.

Accelerating Solutions of Perfect Fluid Hydrodynamics for Initial Energy Density and Life-Time Measurements in Heavy Ion Collisions

A new class of accelerating, exact, explicit and simple solutions of relativistic hydrodynamics is presented. Since these new solutions yield a finite rapidity distribution, they lead to an advanced estimate of the initial energy density and life-time of high energy heavy ion reactions. Accelerating solutions are also given for spherical expansions in arbitrary number of spatial dimensions.Comment: 3 pages, labels in Fig.2b corrected. Based on T. Csorgo's talk at the XXXVIth Int. Symp. Multiparticle Dynamics (ISMD 2006), Paraty, RJ, Brazil. Submitted to the Brazilian Journal of Physic

Understanding the rapidity dependence of the elliptic flow and the HBT radii at RHIC

The pseudo-rapidity dependence of the elliptic flow at various excitation energies measured by the PHOBOS Collaboration in Au+Au collisions at RHIC is one of the surprising results that has not been explained before in terms of hydrodynamical models. Here we show that these data are in agreement with theoretical predictions and satisfy the universal scaling relation predicted by the Buda-Lund hydrodynamical model, based on exact solutions of perfect fluid hydrodynamics. We also show a theoretical prediction on the rapidity and transverse momentum scaling of the HBT radii measured in heavy ion collisions, based on the Buda-Lund model.Comment: 6 pages, 2 figures, proceedings contribution for M. Csanad's talk at the Workshop on Particle Correlations and Femtoscopy 2005, Kromeri