Abstract:We study, in a hydrodynamical approach, the energy dependence of the kaon mT spectra in central Pb+Pb (Au+Au) collisions. We show that the experimental data of the inverse slope parameter can be reproduced with a reasonable choice of both energy-dependent freeze-out temperature and initial conditions.
“…7 and 8. Moreover, recent hydrodynamic calculations [27] that model both the deconfined and hadronic phases provide a quantitative description of the data as shown by the dashed-dotted curve in Fig. 7.…”
Section: Discussion Of Model Explanationsmentioning
Results on charged pion and kaon production in central Pb+Pb collisions at 20A and 30A GeV are presented and compared to data at lower and higher energies. Around 30A GeV a rapid change of the energy dependence for the yields of pions and kaons as well as for the shape of the transverse mass spectra is observed. The change is compatible with the prediction that the threshold for production of a state of deconfined matter at the early stage of the collisions is located at low CERN Super Proton Synchroton energies.
“…7 and 8. Moreover, recent hydrodynamic calculations [27] that model both the deconfined and hadronic phases provide a quantitative description of the data as shown by the dashed-dotted curve in Fig. 7.…”
Section: Discussion Of Model Explanationsmentioning
Results on charged pion and kaon production in central Pb+Pb collisions at 20A and 30A GeV are presented and compared to data at lower and higher energies. Around 30A GeV a rapid change of the energy dependence for the yields of pions and kaons as well as for the shape of the transverse mass spectra is observed. The change is compatible with the prediction that the threshold for production of a state of deconfined matter at the early stage of the collisions is located at low CERN Super Proton Synchroton energies.
“…Another crucial assumption in the SMES is a formation of the longitudinally Lorentz-contacted fireball in rest, that is actually the Landau-type initial conditions for hydrodynamic expansion. It was demonstrated [52], however, that the Landau-type initial conditions are unable to reproduce effective temperatures together with other data (multiplicities and rapidity distributions) at the SPS energies, and that these quantities can be described altogether only when one uses large initial volume with an appropriate velocity distribution (see also [53]). …”
Section: Discussion and Interpretation Of The Resultsmentioning
A method allowing studies of the hadronic matter at the early evolution stage in A+A collisions is developed. It is based on an interferometry analysis of approximately conserved values such as the averaged phase-space density (APSD) and the specific entropy of thermal pions. The plateau found in the APSD behavior vs collision energy at SPS is associated, apparently, with the deconfinement phase transition at low SPS energies; a saturation of this quantity at the RHIC energies indicates the limiting Hagedorn temperature for hadronic matter. It is shown that if the cubic power of effective temperature of pion transverse spectra grows with energy similarly to the rapidity density (that is roughly consistent with experimental data), then the interferometry volume is inverse proportional to the pion APSD that is about a constant because of limiting Hagedorn temperature. This sheds light on the HBT puzzle.
“…22, we show the p T distributions of charged particles in the most central Au + Au collisions at 130A GeV, calculated both with NeXuS fluctuating IC and with averaged IC. Like in the case of Pb + Pb collisions at SPS, we used sudden freezeout, but with lower freezeout temperature, T fo = 128 MeV, the same value used in [54] to fit the inverse slope parameter of kaons, in the same collisions, as shown in Fig. 15 and Table 1 of Section 5.…”
A survey is given on the applications of hydrodynamic model of nucleus-nucleus collisons, focusing especially on i) the resolution of hydrodynamic equations for arbitrary configurations, by using the smoothed-particle hydrodynamic approach; ii) effects of the event-by-event fluctuation of the initial conditions on the observables; iii) decoupling criteria; iv) analytical solutions; and others.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.