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

References in corpus (20)

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• Shape and flow fluctuations in ultra-central Pb+Pb collisions at the LHC
• Photon Emission from a Momentum Anisotropic Quark-Gluon Plasma
• Transverse momentum structure of pair correlations as a signature of collective behavior in small collision systems
• How large is the Knudsen number reached in fluid dynamical simulations of ultrarelativistic heavy ion collisions?
• New information on photon fragmentation functions

Cited by in corpus (9)

• Imprints of fluctuating proton shapes on flow in proton-lead collisions at the LHC
• Non-equilibrium attractor in high-temperature QCD plasmas
• Unified description of hadron yield ratios from dynamical core-corona initialization
• On the elliptic flow of heavy quarkonia in $pA$ collisions
• Accessing the gluonic structure of light nuclei at the Electron Ion Collider
• Elliptic flow coefficients from transverse momentum conservation
• Anomalous features of particle production in high-multiplicity events of pp collisions at the LHC energies
• Initial conditions of bulk matter in ultrarelativistic nuclear collisions
• Pseudothermalization of the quark-gluon plasma