Collectivity and electromagnetic radiation in small systems

Abstract

Collective behaviour has been observed in hadronic measurements of high multiplicity proton+lead collisions at the Large Hadron Collider (LHC), as well as in (proton, deuteron, helium-3)+gold collisions at the Relativistic Heavy-Ion Collider (RHIC). To better understand the evolution dynamics and the properties of the matter created in these small systems, a systematic study of the soft hadronic observables together with electromagnetic radiation from these collisions is performed, using a hydrodynamic framework. Quantitative agreement is found between theoretical calculations and existing experimental hadronic observables. The validity of the fluid dynamical description is estimated by calculating Knudsen and inverse Reynolds numbers. Sizeable thermal yields are predicted for low $p_T$ photons. Further predictions of higher order charged hadron anisotropic flow coefficients and of thermal photon enhancement are proposed.

21 pages, 23 figures

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• Unified description of hadron yield ratios from dynamical core-corona initialization
• On the elliptic flow of heavy quarkonia in $pA$ collisions
• The 3D structure of anisotropic flow in small collision systems at the Relativistic Heavy Ion Collider
• Development of transverse flow at small and large opacities in conformal kinetic theory
• Collectivity in Ultra-Peripheral Pb+Pb Collisions at the Large Hadron Collider
• Progress and Challenges in Small Systems
• Accessing the gluonic structure of light nuclei at the Electron Ion Collider
• Rapidity dependence of initial state geometry and momentum correlations in p+Pb collisions
• Kinematic dependence of azimuthal anisotropies in $p$$+$Au, $d$$+$Au, ${}^3$He+Au at $\sqrt{s_{{}_{NN}}}$ = 200 GeV
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• Elliptic flow coefficients from transverse momentum conservation
• Direct Photons in Hydrodynamic Modeling of Relativistic Nuclear Collisions
• Production and anisotropic flow of thermal photons in collision of $\alpha$-clustered carbon with heavy nuclei at relativistic energies
• Initial conditions of bulk matter in ultrarelativistic nuclear collisions
• Hadronization of correlated gluon fields
• Anomalous features of particle production in high-multiplicity events of pp collisions at the LHC energies
• Light neutral-meson production in pp collisions at $\sqrt{\mathbf{s}}$ = 13 TeV
• Direct-photon production in inelastic and high-multiplicity proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Pseudothermalization of the quark-gluon plasma
• Far-from-equilibrium attractors with a realistic non-conformal equation of state
• Extended applicability domain of viscous anisotropic hydrodynamics in (2+1)-D Bjorken flow with transverse expansion