Abstract
Heavy-ion collisions at relativistic energies probe matter at extreme conditions of temperatures and energy densities. The study of event-by-event fluctuations of experimental observables is crucial to probe the QCD phase transition, locate the critical point, and learn about the associated critical phenomena. At the critical point, all thermodynamic quantities behave anomalously. Fluctuation measurements provide access to thermodynamic response functions. We discuss the methods for obtaining the isothermal compressibility using particle multiplicity fluctuation, and specific heat using fluctuations in mean transverse momentum, temperature, and energy. Lattice QCD calculations have predicted non-monotonic behavior in the higher-order cumulants of conserved quantities at the critical point. Fluctuations in the multiplicity of charged to neutral particles have been measured to understand the formation of domains of disoriented chiral condensates. We review the recent fluctuation results as a function of collision centrality and energy from experiments at SPS, RHIC, and LHC. In addition, we propose to map the temperature fluctuations in η-φ plane to probe local fluctuations of temperature and energy density.
Highlights
According to the theory of Quantum Chromo Dynamics (QCD), under extreme conditions of temperatures and energy densities, normal hadronic matter goes through a phase transition to a system of deconfined quarks and gluons, the quark-gluon plasma (QGP)
Theoretical and experimental studies explore the rich landscape of the QCD phase diagram to understand the nature of the phase transition, locate the critical point, and to learn about the properties of the matter formed
The experimental program to study the QCD phase structure started more than three decades ago at Bevelac, Berkeley and since has covered four generations of experiments at the Brookhaven National Laboratory (BNL) and CERN
Summary
According to the theory of Quantum Chromo Dynamics (QCD), under extreme conditions of temperatures and energy densities, normal hadronic matter goes through a phase transition to a system of deconfined quarks and gluons, the quark-gluon plasma (QGP). Event-by-event fluctuations in a number of observables have been predicted as signatures of the QCD phase transition and the critical point [9, 10, 11]. The nature of phase transitions in a system can be understood by the measurement of thermodynamic response functions These quantities can be accessed experimentally by the fluctuation of measured quantities. While the ensemble average thermodynamic properties like the temperature and volume can be extracted from the mean hadron yields, kT can be accessed through the measurements of the event-by-event multiplicity fluctuations. For a system in thermal equilibrium to a bath at kT (fm3/GeV)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
