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تسجيل مستخدم جديدExperimental results on charge fluctuations in heavy-ion collisions
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We present a subset of experimental results on charge fluctuation from the heavy-ion collisions to search for phase transition and location of critical point in the QCD phase diagram. Measurements from the heavy-ion experiments at the SPS and RHIC energies observe that total charge fluctuations increase from central to peripheral collisions. The net-charge fluctuations in terms of dynamical fluctuation measure $ u_{(+-,dyn)}$ are studied as a function of collision energy (sqsn) and centrality of the collisions. The product of $ u_{(+-,dyn)}$ and $langle N_{ch} rangle$ shows a monotonic decrease with collision energies, which indicates that at LHC energy the fluctuations have their origin in the QGP phase. The fluctuations in terms of higher moments of net-proton, net-electric charge and net-kaon have been measured for various sqsn. Deviations are observed in both $Ssigma$ and $kappasigma^2$ for net-proton multiplicity distributions from the Skellam and hadron resonance gas model for sqsn $<$ 39 GeV. Higher moment results of the net-electric charge and net-kaon do not observe any significant non-monotonic behavior as a function of collision energy. We also discuss the extraction of the freeze-out parameters using particle ratios and experimentally measured higher moments of net-charge fluctuations. The extracted freeze-out parameters from experimentally measured moments and lattice calculations, are found to be in agreement with the results obtained from the fit of particle ratios to the thermal model calculations.
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