Recent results on event-by-event fluctuations from the RHIC Beam Energy Scan program in the STAR experiment

30th Winter Workshop on Nuclear Dynamics

Sahoo, Nihar Ranjan^1

Texas A and M University, College Station

TX

77843, United States^1

关键词: Conserved quantity;    Critical phenomenon;    Dynamical fluctuations;    Event-by-event fluctuations;    Global observables;    Multiplicity distributions;    Relativistic heavy ion collision;    Transverse momenta;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/535/1/012007/pdf
DOI  :  10.1088/1742-6596/535/1/012007

来源: IOP

【 摘 要 】

Event-by-event fluctuations of global observables in relativistic heavy-ion collisions are studied as probes for the QCD phase transition and as tools to search for critical phenomena near the phase boundary. Dynamical fluctuations in mean transverse momentum, identified particle ratios and conserved quantities (such as net-charge, net-baryon) are expected to provide signatures of a de-confined state of matter. Non-monotonic behavior in the higher-moments of conserved quantities as a function of beam energy and collision centrality are proposed as signatures of the QCD critical point. To study the QCD phase transition and locate the critical point, the STAR experiment at RHIC has collected a large amount of data for Au+Au collisions from √sNN= 7.7 - 200 GeV in the RHIC Beam Energy Scan (BES) program. We present the recent beam energy scan results on dynamical fluctuations of particle ratios and two-particle transverse momentum correlations at mid-rapidity. Higher-moments of the net-charge and netproton multiplicity distributions as a function of beam energy will be presented. We give a summary of what has been learnt so far and future prospectives for the BES-II program.