Dissecting the role of initial collision geometry for jet quenching observables in relativistic heavy ion collisions

Abstract

The observation of large azimuthal anisotropy or $v_2$ for hadrons above $p_T>5$ GeV/$c$ in Au+Au collisions at $\sqrt{s_{\mathrm{nn}}}=200$ GeV has been a longstanding challenge for jet quenching models based on perturbative QCD (pQCD). Using a simple jet absorption model, we seek to clarify the situation by exploring in detail how the calculated $v_2$ varies with choices of the collision geometry as well as choices of the path length dependence and thermalization time ${\tau }_0$ in the energy loss formula. Besides the change of eccentricity due to distortion from gluon saturation or event-by-event fluctuation, we find that the $v_2$ is also sensitive to the centrality dependence of multiplicity and the relative size between the matter profile and the jet profile. We find that the $v_2$ calculated for the naive quadratic path length dependence of energy loss, even including eccentricity fluctuation and the gluon saturation, is not enough to describe the experimental data at high $p_T$ ($\sim$ 6 GeV/$c$) in Au+Au collisions. However, it can match the full centrality dependence of $v_2$ data if higher power path length dependence of energy loss is allowed. We also find that the calculated $v_2$ is sensitive to the assumption of the early time dynamics but generally increases with ${\tau }_0$, opposite to what one expects for elliptic flow. This study attests to the importance of confining the initial geometry, possibly by combining jet quenching $v_2$ with elliptic flow and other jet quenching observables, for proper interpretation of the experimental data.

20 pages, 28 figures

References in corpus (33)

• Glauber Modeling in High Energy Nuclear Collisions
• Energy Loss and Flow of Heavy Quarks in Au+Au Collisions at sqrt(s_NN) = 200 GeV
• Calculating the Jet Quenching Parameter from AdS/CFT
• Dihadron azimuthal correlations in Au+Au collisions at sqrt(s_NN)=200 GeV
• Space-time evolution of bulk QCD matter
• MARTINI: An event generator for relativistic heavy-ion collisions
• Direct observation of dijets in central Au+Au collisions at sqrt(s_NN) = 200 GeV
• Effects of fluctuations on the initial eccentricity from the Color Glass Condensate in heavy ion collisions
• Systematic Comparison of Jet Energy-Loss Schemes in a realistic hydrodynamic medium
• Dihadron Tomography of High-Energy Nuclear Collisions in NLO pQCD
• The eccentricity in heavy-ion collisions from Color Glass Condensate initial conditions
• Light quark energy loss in strongly-coupled N = 4 supersymmetric Yang-Mills plasma
• Angular Dependence of Jet Quenching Indicates Its Strong Enhancement Near the QCD Phase Transition
• Gluon energy loss in the gauge-string duality
• Fluctuating initial conditions in heavy-ion collisions from the Glauber approach
• Eccentricity fluctuation effects on elliptic flow in relativistic heavy ion collisions
• Jet energy loss, photon production, and photon-hadron correlations at RHIC
• Tomography of high-energy nuclear collisions with photon-hadron correlations
• Testing AdS/CFT Deviations from pQCD Heavy Quark Energy Loss with Pb+Pb at LHC
• Prospects of medium tomography using back-to-back hadron correlations
• Testing the theory of QGP-induced energy loss at RHIC and the LHC
• Trends in Yield and Azimuthal Shape Modification in Dihadron Correlations in Relativistic Heavy Ion Collisions
• Jet-quenching in a 3D hydrodynamic medium
• Constraint fitting of experimental data with a jet quenching model embedded in a hydrodynamical bulk medium
• Jet quenching in the strongly-interacting quark-gluon plasma
• Jet modification in three dimensional fluid dynamics at next-to-leading twist
• Viscosity from elliptic flow: the path to precision
• Quantitative and Conceptual Considerations for Extracting the Knudsen Number in Heavy Ion Collisions
• Scaling properties in bulk and p${}_{\mathrm{T}}$-dependent particle production near midrapidity in relativistic heavy ion collisions
• Energy loss for heavy quarks in relation to light partons; is radiative energy loss for heavy quarks anomalous?
• Scaling patterns of the suppression of ${\pi }^0$ yields in Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV: links to the transport properties of the QGP
• PHENIX Measurements of Azimuthal Anisotropy for ${\pi }^0$ Production at High $p_T$ in Au+Au Collisions at $\sqrt{s_{NN}}=200$GeV
• ${\pi }^0$-h correlation in Cu+Cu at $\sqrt{s_{NN}}$=200 GeV

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• Observation of a "Ridge" correlation structure in high multiplicity proton-proton collisions: A brief review
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• Fourier Harmonics of High-pT Particles Probing the Fluctuating Intitial Condition Geometries in Heavy-Ion Collisions
• Constraints on the Path-Length Dependence of Jet Quenching in Nuclear Collisions at RHIC and LHC
• Event-by-event azimuthal anisotropy of jet quenching in relativistic heavy ion collisions
• Hard Probe of Geometry and Fluctuations in Heavy Ion Collisions at $\sqrt{s_{{}_{NN}}}=$ 0.2, 2.76, and 5.5 TeV
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• Some new results for "jet" stopping in AdS/CFT
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• Jet Tomography of Harmonic Fluctuations in the Initial Condition of Heavy Ion Collisions
• Qualitative and Quantitative Energy Loss?
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• Jet Quenching in Heavy-Ion Collisions - The Transition Era from RHIC to LHC
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• Longitudinal hydrodynamics from event-by-event Landau initial conditions
• Quantifying a Possibly Reduced Jet-Medium Coupling of the sQGP at the LHC
• Interactions between heavy quarks and tilted QGP fireballs in 200 AGeV Au+Au collisions
• ${\pi }^0$ Azimuthal Anisotropy in Au+Au Collisions at $\sqrt{s_{NN}}=39-200$ GeV from PHENIX: Collision Energy and Path-Length Dependence of Jet-Quenching and the Role of Initial Geometry
• Thermalization of the quark-gluon plasma and dynamical formation of Bose-Einstein Condensate
• Initial Conditions and Global Event Properties from Color Glass Condensate