Model Study of Transverse Expansion and Anti-proton to Proton Ration from ～(197)Au+～(197) Au Collisions at RHIC Energies by RQMD
|School||Central China Normal University|
|Keywords||Transverse momentum spectra Horizontal expansion Collective Flow RQMD Final state particles scattering The heart of a Anti - proton proton yield ratio|
RHIC energies 197 sup> in Au 197 sup> Au collisions in the horizontal expansion of collective movement and the anti-proton proton yield than the model. \Research Center rapidity region transverse mass spectra of different particles or cross-spectrum can be obtained Transverse collective expansion of the collision center area. RQMD model in the 80,000 center of mass energy (SNN) , 1/2 sup> = 200GeV 197 sup> Au 197 sup> Au collisions minimum partial collision. Study the final state hadrons transverse momentum distribution of particles than the charged pi, K, p and (?) The average transverse momentum and comparison with experimental data, we tried to study in high-energy nuclear collisions in the early part of Sub-Class behavior. We will see in high-energy heavy-ion collisions at RHIC energies, there is a strong horizontal expansion movement, and become more intense with increasing collision centrality. This lateral expansion originated in the initial stage of the collision, but mainly in the late collision, some of the heavier particles, such as J / Ψ, The Xi and omega hadron scattering cross-section having a smaller, almost does not participate in the final state re-scattering of hadrons, leave earlier collision system, they demonstrated by the lateral expansion of the movement may be cumulative results from the collision the early part of the sub-stage sub-collective effect. This effect has provided us with a very clear signal collision in the study early evolution of the system nature: if we experimentally measured non-zero Ω particles ellipsoid stream 2 sub >>, it must be the QGP formation of the early part of the sub-system and then j \\ Journal y many eight-fi \\ cited U 'HIrUS scattering caused depends on the initial conditions of the particles in heavy-ion collisions early blocked due to the emphasis on the free affects the dynamical evolution of the entire system, center fast the maximum net baryon (baryon prevent) and net weight disappear in density (baryon penetration) provides a completely different initial conditions for the quark-gluon plasma that may arise. in a collision early baryon number transport is an important physical quantities of the high-energy heavy-ion collisions, which affects the balance of the initial state parton, particle generation, the thermodynamic or chemical equilibrium and collective expansion process. experimental baryon penetration ratio is obtained by measuring the can, so we also use RQMDvZ.4 a = 200GeV under the m'a ten weeks * collision final state particle system in the production of antiprotons and protons amount ratio p / p ratio of rapidity, transverse momentum, centrality and energy dependence of the collision, and the Monte Carlo results and experimental comparison. Studies have shown: the plant in the central rapidity region is not obvious rapidity dependence, the closer to the edge of the rapidity region, p / P downward trend p / p in the low transverse momentum region; in central collision or minimum Unbiased event, as the transverse momentum increases with increasing; p with the collision than the experimental results of the heart of a performance slightly stronger with increased heart of a decreasing trend, especially then scattering UJRQMD model; p / p with the collision in the central rapidity region, centroid increased energy and rapid increases, consistent with the experimental results; ** D at low energies, the final state particles scattering the prophecy: But in the * mC energy under the final state particles in the scattering ** The predicted D p / p value is smaller than the experimental value, which shows relatively low energy the RHIC energy level plant m'a + m'a collision in the final state hadrons scattering is down.