ﻻ يوجد ملخص باللغة العربية
A dense form of matter is formed in relativistic heavy ion collisions. The constituent degrees of freedom in this dense matter are currently unknown. Long-range, forward-backward multiplicity correlations (LRC) are expected to arise due to multiple partonic interactions. Model independent and dependent arguments suggest that such correlations are due to multiple partonic interactions. These correlations are predicted in the context of the Dual Parton Model (DPM). The DPM describes soft partonic processes and hadronization. This model indicates that the underlying mechanism creating these long-range multiplicity correlations in the bulk matter is due to multiple partonic interactions. In this thesis, long-range multiplicity correlations have been studied in heavy ion (Au+Au and Cu+Cu) and hadron-hadron ({it pp}) collisions. The behavior has been studied as a function of pseudorapidity gap ($Deltaeta$) about $eta$ = 0, the centrality, atomic number, and incident energy dependence of the colliding particles. Strong, long-range correlations ($Deltaeta >$ 1.0) as a function of $Deltaeta$ are found for central collisions of %(full overlap) heavy ions at an energy of $sqrt{s_{NN}}$ = 200 GeV. This indicates substantial amounts of dense partonic matter are formed in central heavy ion collisions at an energy of $sqrt{s_{NN}}$ = 200 GeV.
Forward-backward multiplicity correlations have been measured with the STAR detector for Au+Au, Cu+Cu and {it p+p} collisions at $sqrt{s_{NN}}$ = 200 GeV. A strong, long-range correlation is observed for central heavy ion collisions that vanishes in
Using the string melting version of a multiphase transport (AMPT) model, we focus on the evolution of thermodynamic properties of the central cell of parton matter produced in Au+Au collisions ranging from 200 GeV down to 2.7 GeV. The temperature and
In heavy-ion ({it A-A}) collisions, the correlations among the particles produced across wide range in rapidity, probe the early stages of the reaction. The analyses of forward-backward multiplicity correlations in these collisions are complicated by
A systematic analysis of correlations between different orders of $p_T$-differential flow is presented, including mode coupling effects in flow vectors, correlations between flow angles (a.k.a. event-plane correlations), and correlations between flow
The direct photon spectra and flow ($v_2$, $v_3$) in heavy-ion collisions at SPS, RHIC and LHC energies are investigated within a relativistic transport approach incorporating both hadronic and partonic phases -- the Parton-Hadron-String Dynamics (PH