Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userOn the hadron production from the quark-gluon plasma phase in ultra-relativistic heavy-ion collisions
85
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
We describe the quark gluon plasma (QGP) as a thermalized quark-gluon system, the thermalized QGP phase of QCD. The hadronization of the thermalized QGP phase is given in a way resembling a coalescence model with correlated quarks and anti-quarks. The input parameters of the approach are the spatial volumes of the hadronization. We introduce three dimensionless parameters C_M, C_B and C_bar{B} related to the spatial volumes of the production of low-lying mesons (M), baryons (B) and antibaryons (bar{B}). We show that at the temperature T= 175 MeV our predictions for the ratios of multiplicities agree good with the presently available set of hadron ratios measured for various experiments given by NA44, NA49, NA50 and WA97 Collaborations on Pb+Pb collisions at 158 GeV/nucleon, NA35 Collaboration on S+S collisions and NA38 Collaboration on O+U and S+U collisions at 200 GeV/nucleon.
rate research
Read More
Recent data on the production of $D$ mesons and $Lambda_c^+$ baryons in heavy ion collisions at the Relativistic Heavy Ion Collider and the Large Hadron Collider exhibit a number of striking characteristics such as enhanced yield ratios $D_s^+/D^0$, $Lambda_c^+/D^0$ and their transverse momentum dependences. In this paper, we derive the momentum dependence of open charm mesons and singly charmed baryons produced in ultra-relativistic heavy ion collisions via the equal-velocity quark combination. We present analytic expressions and numerical results of yield ratios and compare them with the experimental data available. We make predictions for other charmed hadrons.
We study the evolution of the quark-gluon composition of the plasma created in ultra-Relativistic Heavy-Ion Collisions (uRHICs) employing a partonic transport theory that includes both elastic and inelastic collisions plus a mean fields dynamics associated to the widely used quasi-particle model. The latter, able to describe lattice QCD thermodynamics, implies a chemical equilibrium ratio between quarks and gluons strongly increasing as $Trightarrow T_c$, the phase transition temperature. Accordingly we see in realistic simulations of uRHICs a rapid evolution from a gluon dominated initial state to a quark dominated plasma close to $T_c$. The quark to gluon ratio can be modified by about a factor of $sim 20$ in the bulk of the system and appears to be large also in the high $p_T$ region. We discuss how this aspect, often overflown, can be important for a quantitative study of several key issues in the QGP physics: shear viscosity, jet quenching, quarkonia suppression. Furthermore a bulk plasma made by more than $80%$ of quarks plus antiquarks provides a theoretical basis for hadronization via quark coalescence.
A model of statistical quark-gluon plasma formation is considered.We look the dilepton production at critical temperature $T_{c}sim170 Mev $ and completely free out temperature $T=150 MeV$ with the initial temperature as $T_{0}=570,400 (250) MeV$. Now we consider that quark mass is depending on the coupling value through parameterisation factor of the fireball formation and temperature. The rate of production is shown for invariant mass $M$ at the particular value of $ E=2.0,3.0 GeV$.It shows the significant production of leptons in this process for small value of invariant mass. However, the quark-hadron phase transition is a very weakly changed in the entropy of the system during this process of hadronisation.
Entropy production in the compression stage of heavy ion collisions is discussed within three distinct macroscopic models (i.e. generalized RHTA, geometrical overlap model and three-fluid hydrodynamics). We find that within these models sim 80% or more of the experimentally observed final-state entropy is created in the early stage. It is thus likely followed by a nearly isentropic expansion. We employ an equation of state with a first-order phase transition. For low net baryon density, the entropy density exhibits a jump at the phase boundary. However, the excitation function of the specific entropy per net baryon, S/A, does not reflect this jump. This is due to the fact that for final states (of the compression) in the mixed phase, the baryon density rho_B increases with sqrt{s}, but not the temperature T. Calculations within the three-fluid model show that a large fraction of the entropy is produced by nuclear shockwaves in the projectile and target. With increasing beam energy, this fraction of S/A decreases. At sqrt{s}=20 AGeV it is on the order of the entropy of the newly produced particles around midrapidity. Hadron ratios are calculated for the entropy values produced initially at beam energies from 2 to 200 AGeV.
We investigate the relativistic equation of state of hadronic matter and quark-gluon plasma at finite temperature and baryon density in the framework of the non-extensive statistical mechanics, characterized by power-law quantum distributions. We impose the Gibbs conditions on the global conservation of baryon number, electric charge and strangeness number. For the hadronic phase, we study an extended relativistic mean-field theoretical model with the inclusion of strange particles (hyperons and mesons). For the quark sector, we employ an extended MIT-Bag model. In this context we focus on the relevance of non-extensive effects in the presence of strange matter.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
