pT distribution of hyperons in 200A GeV Au-Au by smoothed particle hydrodynamics

The transverse momentum distributions for hadrons in 200GeV Au-Au collision at RHIC is calculated using a smoothed particle hydrodynamics code SPheRIO, and are compared with the data from STAR and PHOBOS Collaborations. By employing the equation of state which explicitly incorporate the strangeness conservation and introducing strangeness chemical potential into the code, the transverse spectrums give a reasonable description for the experimental data.Comment: 3 pages, 6 figure

Incident-energy dependence of the effective temperature in heavy-ion collisions

We study the behaviour of the effective temperature for K+ in several energy domains. For this purpose, we apply the recently developed SPheRIO code for hydrodynamics in 3+1 dimensions, using both Landau-type compact initial conditions and spatially more spread ones. We show that initial conditions given in small volume, like Landau-type ones, are unable to reproduce the effective temperature together with other data (multiplicities and rapidity distributions). These quantities can be reproduced altogether only when using a large initial volume with an appropriate velocity distribution

Squeezed correlations among particle-antiparticle pairs

The hadronic correlation among particle-antiparticle pairs was highlighted in the late 1990's, culminating with the demonstration that it should exist if the masses of the hadrons were modified in the hot and dense medium formed in high energy heavy ion collisions. They were called Back-to-Back Correlations (BBC) of particle-antiparticle pairs, also known as squeezed correlations. However, even though they are well-established theoretically, such hadronic correlations have not yet been experimentally discovered. Expecting to compel the experimentalists to search for this effect, we suggest here a clear way to look for the BBC signal, by constructing the squeezed correlation function of phi-phi and K+K- pairs at RHIC energies, plotted in terms of the average momentum of the pair, K12=(k1+k2)/2, inspired by procedures adopted in Hanbury-Brown & Twiss (HBT) correlations.Comment: 5 pages, 3 figures with parts (a) and (b), to be published in the Proceedings of the XXXVIII International Symposium on Multiparticle Dynamics (ISMD 2008); plotting region in m*-axis of Fig.1a corrected; few typos corrected in the tex

Squeezed particle-antiparticle correlations

A novel type of correlation involving particle-antiparticle pairs was found out in the 1990's. Currently known as Squeezed or Back-to-Back Correlations (BBC), they should be present if the hadronic masses are modified in the hot and dense medium formed in high energy heavy ion collisions. Although well-established theoretically, such hadronic correlations have not yet been observed experimentally. In this phenomenological study we suggest a promising way to search for the BBC signal, by looking into the squeezed correlation function of phi phi and K^+ K^- pairs at RHIC energies, as function of the pair average momentum, K_{12}=(k_1+k_2)/2. The effects of in-medium mass-shift on the identical particle correlations (Hanbury-Brown & Twiss effect) are also discussed.Comment: 6 pages, 4 figures, presented at the IV Workshop on Particle Correlations and Femtoscopy (WPCF 2008), Krakow, Poland, September 11-14, 200

Confronting particle emission scenarios with strangeness data

We show that a hadron gas model with continuous particle emission instead of freeze out may solve some of the problems (high values of the freeze out density and specific net charge) that one encounters in the latter case when studying strange particle ratios such as those by WA85. This underlines the necessity to understand better particle emission in hydrodynamics to be able to analyze data. It also re-opens the possibility of a quark-hadron transition occuring with phase equilibrium instead of explosively.Comment: 13 pages, 2 figures, to appear in Phys. Rev. Let

HBT Effect with fluctuating initial conditions and continuous emission

Submitted by Suelen Oliveira ([email protected]) on 2011-10-10T20:11:06Z No. of bitstreams: 1 HBT EFFECT WITH FLUCTUATING INITIAL.pdf: 176879 bytes, checksum: 612690ca0698da3a4fce958a8b888892 (MD5)Approved for entry into archive by Barbara Milbrath([email protected]) on 2011-10-11T18:17:49Z (GMT) No. of bitstreams: 1 HBT EFFECT WITH FLUCTUATING INITIAL.pdf: 176879 bytes, checksum: 612690ca0698da3a4fce958a8b888892 (MD5)Made available in DSpace on 2011-10-11T18:17:49Z (GMT). No. of bitstreams: 1 HBT EFFECT WITH FLUCTUATING INITIAL.pdf: 176879 bytes, checksum: 612690ca0698da3a4fce958a8b888892 (MD5) Previous issue date: 2005We study effects of the event-by-event fluctuation of the initial conditions and the continuous pion emission during the whole development of the hot and dense matter formed in high-energy collisions on the two-pion interferometry. Important deviations occur, from the standard version of hydrodynamics with smooth initial conditions and a sudden freeze-out on a T = Tfo hypersurface. Comparison with data at RHIC shows that this description can give account of the mT dependence of RL and Rs and significantly improves Ro with respect to the usual version

HBT Effect with fluctuating initial conditions and continuous emission

We study effects of the event-by-event fluctuation of the initial conditions and the continuous pion emission during the whole development of the hot and dense matter formed in high-energy collisions on the two-pion interferometry. Important deviations occur, from the standard version of hydrodynamics with smooth initial conditions and a sudden freeze-out on a T = Tfo hypersurface. Comparison with data at RHIC shows that this description can give account of the mT dependence of RL and Rs and significantly improves Ro with respect to the usual version