Production of Photons and Dileptons in the Glasma

Abstract

We study the production of photons and dileptons during the pre-equilibrium Glasma stage in heavy ion collisions and discuss the implications in light of the PHENIX data. We find that the measured distributions of such electromagnetic emissions, while having some features not well understood if hypothesized to entirely arise from a thermalized Quark-Gluon Plasma, have some qualitative features that might be described after including effects from a thermalizing Glasma. The shape and centrality dependence of the transverse momentum spectra of the so-called "thermal photons" are well described. The mass and transverse momentum dependence of intermediate mass dileptons also agree with our estimates. The low transverse momenta from which the excessive dileptons (in low to intermediate mass region) arise is suggestive of emissions from a Bose condensate. We also predict the centrality dependence of dilepton production. Uncertainties in the current approach and improvements in the future are discussed.

24 pages, 7 figures, new results and references added in v2

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Cited by in corpus (40)

• Heavy Ion Collisions: Achievements and Challenges
• Effective QCD and transport description of dilepton and photon production in heavy-ion collisions and elementary processes
• Production and Elliptic Flow of Dileptons and Photons in the semi-Quark Gluon Plasma
• Hadronic and partonic sources of direct photons in relativistic heavy-ion collisions
• Gluon Transport Equation in the Small Angle Approximation and the Onset of Bose-Einstein Condensation
• Quark production, Bose-Einstein condensates and thermalization of the quark-gluon plasma
• Direct real photons in relativistic heavy ion collisions
• The Glasma, Photons and the Implications of Anisotropy
• Electromagnetic response of quark-gluon plasma in heavy-ion collisions
• Over-populated gauge fields on the lattice
• Photon elliptic flow in relativistic heavy-ion collisions: hadronic versus partonic sources
• Beam-energy and centrality dependence of direct-photon emission from ultra-relativistic heavy-ion collisions
• Thermalization of gluons with Bose-Einstein condensation
• The Magneto-Sono-Luminescence and its signatures in photon and dilepton production in heavy ion collisions
• Thermalization and Bose-Einstein Condensation in Overpopulated Glasma
• Holographic dilepton production in a thermalizing plasma
• Geometrical Scaling of Direct-Photon Production in Hadron Collisions from RHIC to the LHC
• Photons from the Early Stages of Relativistic Heavy Ion Collisions
• Effective kinetic description of the expanding overoccupied Glasma
• Glasma Evolution and Bose-Einstein Condensation with Elastic and Inelastic Collisions
• Photon production from gluon mediated quark-anti-quark annihilation at confinement
• Towards azimuthal anisotropy of direct photons
• Prompt, pre-equilibrium, and thermal photons in relativistic nuclear collisions
• Electromagnetic currents induced by color fields
• Photons from thermalizing matter in heavy ion collisions
• Direct Photons in Hydrodynamic Modeling of Relativistic Nuclear Collisions
• Scaling properties of direct photon yields in heavy ion collisions
• Photon radiation in hot nuclear matter by means of chiral anomalies
• Geometrical scaling of prompt photons in heavy ion collisions
• INFN What Next: Ultra-relativistic Heavy-Ion Collisions
• Dilepton Spectroscopy of QCD Matter at Collider Energies
• Phenomenology of collinear photon emission from quark-gluon plasma in $AA$ collisions
• Probing confinement by direct photons and dileptons
• Anisotropy of thermal dileptons
• The Extraordinary Glow
• Asymmetric vector mesons produced in nuclear collisions
• The $m$'bottom-up parton system with two momentum scales
• On Collective Properties of Dense QCD Matter
• Centrality dependence of low-momentum direct-photon production in Au$+$Au collisions at $\sqrt{s_{{}_{NN}}}=200$ GeV
• Geometrical Scaling of Direct Photons in Relativistic Heavy Ion and d+Au Collisions