Accessing proton number fluctuations in limited regions of phase space

Abstract

In heavy ion collisions particle distributions fluctuate from event to event. It is interesting to study local fluctuations of a specific particle specie, e.g. baryons, in the transverse plane. Fluctuations of the harmonic flow provide an integrated measure of such fluctuations. An alternative approach is to study proton number fluctuations measured in a relatively narrow azimuthal angle window. Due to the transverse flow, particles registered in a narrow azimuthal angle window are emitted predominantly from a region of the fireball located at the same azimuthal angle. Similarly, it is informative to measure the covariance of the number of protons emitted in two opposite windows of azimuthal angles. The main difficulty lies in distinguishing effects of local baryon density fluctuations in the transverse plane from global particle density and collective flow fluctuations. These global volume and flow fluctuations can be estimated using some reference particles, e.g. charged mesons. Reliable estimates of such fluctuations can be constructed both for the second factorial cumulant of the proton number in an azimuthal angle window and for the covariance between two such windows. The simultaneous measurement of both quantities provides a sensitive probe of local baryon number fluctuations superimposed on top of a fluctuating fireball background density.

References in corpus (42)

• Collective flow and viscosity in relativistic heavy-ion collisions
• The equation of state in (2+1)-flavor QCD
• Event-by-Event Fluctuations in Heavy Ion Collisions and the QCD Critical Point
• Elliptic and triangular flow in event-by-event (3+1)D viscous hydrodynamics
• Femtoscopy in Relativistic Heavy Ion Collisions: Two Decades of Progress
• Non-Gaussian fluctuations near the QCD critical point
• 3+1D hydrodynamic simulation of relativistic heavy-ion collisions
• Alternative ansatz to wounded nucleon and binary collision scaling in high-energy nuclear collisions
• Energy Dependence of Moments of Net-proton Multiplicity Distributions at RHIC
• Mapping the Phases of Quantum Chromodynamics with Beam Energy Scan
• Search for the QCD Critical Point with Fluctuations of Conserved Quantities in Relativistic Heavy-Ion Collisions at RHIC : An Overview
• The production of photons in relativistic heavy-ion collisions
• Properties of hot and dense matter from relativistic heavy ion collisions
• Slowing Out of Equilibrium Near the QCD Critical Point
• Hydrodynamic Models for Heavy Ion Collisions
• Beam-Energy Dependence of Directed Flow of Protons, Antiprotons and Pions in Au+Au Collisions
• Non-monotonic energy dependence of net-proton number fluctuations
• Hydro+: hydrodynamics with parametric slowing down and fluctuations near the critical point
• Dynamical initial state model for relativistic heavy-ion collisions
• Using Higher Moments of Fluctuations and their Ratios in the Search for the QCD Critical Point
• Cumulants and Correlation Functions of Net-proton, Proton and Antiproton Multiplicity Distributions in Au+Au Collisions at energies available at the BNL Relativistic Heavy Ion Collider
• Volume fluctuations and higher order cumulants of the net baryon number
• Equation of state at finite densities for QCD matter in nuclear collisions
• Transverse momentum fluctuations and their correlation with elliptic flow in nuclear collision
• Proton number fluctuation as a signal of the QCD critical end-point
• Directed flow, a signal for the phase transition in Relativistic Nuclear Collisions?
• Measurement of higher cumulants of net-charge multiplicity distributions in Au$+$Au collisions at $\sqrt{s_{{}_{NN}}}=7.7-200$ GeV
• Dynamically integrated transport approach for heavy-ion collisions at high baryon density
• Longitudinal dynamics and particle production in relativistic nuclear collisions
• Chiral symmetry restoration versus deconfinement in heavy-ion collisions at high baryon density
• Cumulants and Correlation Functions vs the QCD phase diagram
• Energy Dependence of Multiplicity Fluctuations in Heavy Ion Collisions at the CERN SPS
• Transits of the QCD Critical Point
• Hybrid model with dynamical sources for heavy-ion collisions at BES energies
• GLISSANDO 3: GLauber Initial-State Simulation AND mOre..., ver. 3
• Large Baryon Densities Achievable in High Energy Heavy Ion Collisions Outside the Central Rapidity Region
• Space-Time Picture of Baryon Stopping in the Color-Glass Condensate
• Correspondence between HBT radii and the emission zone in non-central heavy ion collisions
• Partial correlation analysis method in ultra-relativistic heavy-ion collisions
• Comprehensive simulation of heavy-ion collisions at non-zero baryon chemical potential
• Multi-particle correlations, cumulants, and moments sensitive to fluctuations in rare-probe azimuthal anisotropy in heavy ion collisions
• Acceptance dependence of factorial cumulants, long-range correlations, and the antiproton puzzle