J/? Elliptic Flow Of STAR Heavy-ion Collisions And Anisotropic Flow Of AMPT Model

Lattice QCD predicted at extreme high temperature and energy densities,there could be a phase transition from hadronic phase to a deconfined state of partonic matter phase,called the Quark-Gluon Plasma(QGP).Unlike light quarks,heavy quarks remain the same during the process of system evolution or interacting with the medium.Considering the larger mass while comparing to light quarks,heavy quarks do not easily interact with with the medium,thus carried more information of the partonic stage in the early stage of collisions.Also the interactions between heavy quarks and the medium are more sensitive to the dynamics of the system evolution,heavy quarks are regarded as the ideal probes to anaylize the strong interacting of QCD matter.Color screening of the cc binding potential in the deconfined medium in relativistic heavy-ion collisions leads to the suppression of J/? meson production,thus this suppression could be the a signature of QGP formation.But J/? suppression observed in experiments can also be affected by other hot and cold nuclear effects,especially the J/? reconstructed by well thermalized quarks in the medium,are still hard to distinguish both in experiment and theoretical calculation.In addition,charm quarks are more difficult to be thermalized due to the larger mass than light quarks,so measuring the J/? elliptic flow could study whether charm quarks participate in the collective motion,along with the information of thermalized condition from the production of heavy-ion collisions.In this thesis,the anisotropic flow of particle productions from heavy-ion collisions with respect to the reaction plane has been used to analyze the system evolution.In non-central collision,the collision is anisotropic in spatial space because of the almond shape of collision area.The initial spatial anisotropic would transform into final momentum anisotropic through the particle interactions.The elliptic flow(v2)is the second harmonic coefficient of Fourier expansion the final momentum azimuthal anisotropic.In this thesis we analyzed the J/? elliptic flow in different centrality and transverse momentum windows,and several physical characteristics of anistropic flow by AMPT model.First,the data of Au+Au collisions at 200 GeV from STAR experiment(year 2011)have been used to analyse the J/? elliptic flow.The J/? particles are reconstructed through electron-pair channel,while the electrons are selected by STAR detectors(TPC,TOF,BEMC)under the proper purity and statistic.At last we obtain several J/? v2 results from different centrality and transverse momentum windows.The results show J/? elliptic flow is consistent with zero within errors from transverse momentum 2GeV/c to 10GeV/c.The comparison between experimental results and theoretically calculations indicate that,J/? with relative large momentum are not dominantly produced by coalescence of thermalized charm quarks,which is consistent with the conclusion of year 2010.Considering there are few events which contain the J/? signal,large statistic errors couple with the 2010 results.With nearly the same amount events comparing to 2010,J/? v2 results will be more accurate,and stronger conclusion could be made from this result.With a multiphase transport(AMPT)model,we investigate the relation between the magnitude,fluctuations,and correlations of the initial state spatial anisotropy ?n and the final state anisotropic flow coefficients vn in Au+Au collisions at(?)= 200GeV.It is found that the relative eccentricity fluctuations in AMPT account for the observed elliptic flow fluctuations,both are in agreement with the elliptic flow fluctuation measurements from the STAR experiment.In addition,the studies based on two-and multiparticle correlations and event-by-event distributions of the anisotropies suggest that the elliptic-power function is a promising candidate of the underlying probability density function of the event-by-event distributions of ?n as well as vn.Furthermore,the correlations between different order symmetry planes and harmonics in the initial coordinate space and final state momentum space are presented.Nonzero values of these correlations have been observed.The comparison between our calculations and data will,in the future,shed new insight into the nature of the fluctuations of the quark-gluon plasma produced in heavy ion collisions.In addition,With a multiphase transport(AMPT)model we investigate the elliptic(v2),triangular(v3),and quadrangular(v4)flow of charged particles in Pb+Pb collisions at(?)=5.02TeV.We then compare our flow results with the published ALICE flow results.We find our AMPT simulated results are consistent with ALICE experimental data.