Triangular flow of thermal photons from an event-by-event hydrodynamic model for 2.76A TeV Pb+Pb collisions at LHC

Abstract

We calculate the triangular flow parameter $v_3$ of thermal photons from an event-by-event ideal hydrodynamic model for $0--40\%$ central collisions of Pb nuclei at $\sqrt{s_{NN}}$=2.76 TeV at LHC. $v_3$ determined with respect to the participant plane (PP) is found to be non-zero, positive and its $p_T$ dependence is qualitatively similar to the elliptic flow parameter $v_2$(PP) of thermal photons in the range $1\le p_T\le 6$ GeV/$c$. In the range $p_T\le$ 3 GeV/$c$, $v_3$(PP) is found to be about $50--75\%$ of $v_2$(PP) and for $p_T>$ 3 GeV/$c$ the two anisotropy parameters become comparable. The local fluctuations in the initial density distribution as well as the initial global geometry of the produced matter in the event-by-event hydrodynamic framework are responsible for this substantial value of $v_3(\mathrm{PP})$. However, as expected, the triangular flow parameter calculated with respect to the reaction plane $v_3$(RP) is found to be close to zero. We show that $v_3$(PP) strongly depends on the value of the fluctuation size scale $\sigma$ especially in the higher $p_T(\ge 3\mathrm{GeV}/c)$ region where a larger value of $\sigma$ results in a smaller $v_3(\mathrm{PP})$. In addition, the $v_3(\mathrm{PP})$ is found to increase with the assumed formation time of the thermalized system.

6 pages, 5 figures

References in corpus (9)

• Elliptic and triangular flow in event-by-event (3+1)D viscous hydrodynamics
• Event-by-event hydrodynamics and elliptic flow from fluctuating initial state
• On the necessity to include event-by-event fluctuations in experimental evaluation of elliptical flow
• Importance of Granular Structure in the Initial Conditions for the Elliptic Flow
• Transverse-momentum fluctuations in relativistic heavy-ion collisions from event-by-event viscous hydrodynamics
• Elliptic flow of thermal photons and formation time of quark gluon plasma at RHIC
• Enhancement of thermal photon production in event-by-event hydrodynamics
• Multiplicities and $p_T$ spectra in ultrarelativistic heavy ion collisions from a next-to-leading order improved perturbative QCD + saturation + hydrodynamics model
• Direct photons from relativistic heavy-ion collisions

Cited by in corpus (9)

• Relativistic hydrodynamics in heavy-ion collisions: general aspects and recent developments
• Anisotropic flow of thermal photons at RHIC and LHC
• Photon production from Pb+Pb collisions at {$\sqrt{s_{\mathrm{NN}}}$} = 5.02 TeV at LHC and at {$\sqrt{s_{\mathrm{NN}}}$} = 39 TeV at FCC
• Directed flow of photons in Cu+Au collisions at RHIC
• Ratio of photon anisotropic flow in relativistic heavy ion collisions
• Thermal photon $v_3$ at LHC from fluctuating initial conditions
• Photon spectra and anisotropic flow in heavy ion collisions at the top RHIC energy within the integrated hydrokinetic model with photon hadronization emission
• Zeroing in on the initial state -- tomography using bulk, jets and photons
• Higher order anisotropies in hydrodynamics