Article

Rapidity dependence of charged antihadron to hadron ratios in Au+Au collisions at sqrt[s(NN)]=200 GeV.

Niels Bohr Institute, Blegdamsvej 17, University of Copenhagen, Copenhagen 2100, Denmark.
Physical Review Letters (Impact Factor: 7.73). 04/2003; 90(10):102301. DOI: 10.1103/PhysRevLett.90.102301
Source: PubMed

ABSTRACT We present ratios of the numbers of charged antihadrons to hadrons (pions, kaons, and protons) in Au+Au collisions at sqrt[s(NN)]=200 GeV as a function of rapidity in the range y=0-3. While the ratios at midrapidity are approaching unity, the K(-)/K(+) and p;/p ratios decrease significantly at forward rapidities. An interpretation of the results within the statistical model indicates a reduction of the baryon chemical potential from mu(B) approximately 130 MeV at y=3 to mu(B) approximately 25 MeV at y=0.

0 Bookmarks
 · 
135 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: The measurement of strangeness is a valuable tool for understanding the reaction mechanism of nuclear collisions since all the strange particles need to be created during the reaction. Also, strangeness enhancement is one of the predicted signals of the QGP. In the present work we will discuss the behaviour of the strangeness production (i.e. K/pi ratio) with rapidity and baryo-chemical potential in Au+Au collisions at 62.4 A GeV. In this particular reaction, BRAHMS is able to identify particles over 3.5 rapidity units and thereby cover a wide range of bar {p}/p ratios, including the fragmentation region. We will show spectra and ratios of identified particles as a function of pT and rapidity.
    International Journal of Modern Physics E-nuclear Physics - IJMPE. 01/2007; 16:2035-2040.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Form of matter created in high-energy heavy ion collisions is pertinent to color deconfinement. We calculate time dependences of number densities of pions, rhos, kaons, vector kaons, free quarks and antiquarks. Due to medium screening which leads to constant confinement at large distances, meson-meson reactions A(q1 bar q1 ) + B(q2 bar q2 ) -> q1 +bar q1 + q2 +bar q2 in hadronic matter below the critical temperature Tc produce an appreciable amount of quarks and antiquarks freely moving in hadronic matter and establish a new mechanism for deconfinement of quarks and antiquarks in hadronic matter. We therefore arrive at a new form of matter below Tc: hadrons plus free quarks and antiquarks.
    International Journal of Modern Physics E 09/2010; 19:1856-1865. · 0.84 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We review some recent highlights from the applications of statistical-thermal models to different experimental measurements and lattice QCD thermodynamics, that have been made during the last decade. We start with a short review of the historical milestones on the path of constructing statistical-thermal models for heavy-ion physics. We discovered that Heinz Koppe formulated in 1948 an almost complete recipe for the statistical-thermal models. In 1950, Enrico Fermi generalized this statistical approach, in which he started with a general cross-section formula and inserted into it simplifying assumptions about the matrix element of the interaction process that likely reflects many features of the high-energy reactions dominated by density in the phase space of final states. In 1964, Hagedorn systematically analysed the high-energy phenomena using all tools of statistical physics and introduced the concept of limiting temperature based on the statistical bootstrap model. It turns to be quite often that many-particle systems can be studied with the help of statistical-thermal methods. The analysis of yield multiplicities in high-energy collisions gives an overwhelming evidence for the chemical equilibrium in the final state. The strange particles might be an exception, as they are suppressed at lower beam energies. However, their relative yields fulfill statistical equilibrium, as well. We review the equilibrium statistical-thermal models for particle production, fluctuations and collective flow in heavy-ion experiments. We also review their reproduction of the lattice QCD thermodynamics at vanishing and finite chemical potential. During the last decade, five conditions have been suggested to describe the universal behavior of the chemical freeze out parameters.
    International Journal of Modern Physics A 10/2014; 17(17). · 1.09 Impact Factor