Dimuon transverse momentum spectra as a tool to characterize the emission region in heavy-ion collisions

Abstract

Previous dilepton measurements in heavy-ion collisions have mainly focused on invariant mass spectra to clarify in-medium changes of vector meson properties. However, a dimuon is characterized by two scales -- invariant mass $M$ and transverse momentum $p_T$. Like transverse momentum spectra of hadrons, $p_T$ spectra of dileptons arise from an interplay between emission temperature and collective transverse flow, whereas the invariant mass is insensitive to flow. Having two control parameters of which only one is sensitive to flow allows at given $M$ to characterize the emission region in terms of average temperature and flow. Thus, one is able to study what phases of the fireball evolution radiate into a given mass window. We demonstrate this technique using the dimuon transverse momentum spectra measured by the NA60 collaboration and present strong arguments that a thermalized evolution phase with $T>170$ MeV leaves an imprint in the spectra.

References in corpus (18)

• Thermal phenomenology of hadrons from 200 AGeV S+S collisions
• First Measurement of the rho Spectral Function in High-Energy Nuclear Collisions
• Space-time evolution of bulk QCD matter
• Observable implications of geometrical and dynamical aspects of freeze-out in heavy ion collisions
• Comprehensive Interpretation of Thermal Dileptons at the SPS
• The $\epem\toπ^+π^-π^+π^-$, $K^{+}{K}^{-}{\pi }^{+}{\pi }^{-}$, and $K^{+}{K}^{-}{K}^{+}{K}^{-}$ Cross Sections at Center-of-Mass Energies 0.5--4.5 \gev Measured with Initial-State Radiation
• Thermal Photons and Lepton Pairs from Quark Gluon Plasma and Hot Hadronic Matter
• Properties of $\rho$ and $\omega$ Mesons at Finite Temperature and Density as Inferred from Experiment
• NA60 results on the rho spectral function in In-In collisions
• Thermal Dimuon Yields at NA60
• Recent results from Pb-Au collisions at 158 GeV/c per nucleon obtained with the CERES spectrometer
• Phases of QCD, Thermal Quasiparticles and Dilepton Radiation from a Fireball
• First measurement of the rho spectral function in nuclear collisions
• A model for the spacetime evolution of heavy-ion collisions at RHIC
• Properties of the $\omega$ Meson at Finite Temperature and Density
• Elliptic flow of thermal photons and dileptons
• A comprehensive description of multiple observables in heavy-ion collisions at SPS
• What does the rho-meson do? In-medium mass shift scenarios versus hadronic model calculations

Cited by in corpus (33)

• Thermal Dileptons as Fireball Thermometer and Chronometer
• Evidence for the production of thermal muon pairs with masses above 1 GeV/c^2 in 158A GeV Indium-Indium Collisions
• NA60 results on thermal dimuons
• The Chiral Restoration Transition of QCD and Low Mass Dileptons
• Measurements of Dielectron Production in Au$+$Au Collisions at $\sqrt{s_{\mathrm{NN}}}$ = 200 GeV from the STAR Experiment
• Dielectron Mass Spectra from Au+Au Collisions at $\sqrt{s_{\mathrm{NN}}}$ = 200 GeV
• NA60 results on the rho spectral function in In-In collisions
• Thermal Dileptons from Coarse-Grained Transport as Fireball Probes at SIS Energies
• Low Mass Dimuons Produced in Relativistic Nuclear Collisions
• Dilepton production in nucleus-nucleus collisions at top SPS energy within the Parton-Hadron-String Dynamics (PHSD) transport approach
• Coherent lepton pair production in hadronic heavy ion collisions
• Thermal dileptons at SPS energies
• Measurement of dielectron production in central Pb-Pb collisions at $\sqrt{{\text{s}}_{\mathrm{NN}}}$ = 2.76 TeV
• Dimuon radiation at the CERN SPS within a (3+1)d hydrodynamic+cascade model
• Dilepton flow and deconfinement phase transition in heavy ion collisions
• Energy, centrality and momentum dependence of dielectron production at collider energies in a coarse-grained transport approach
• Dielectron production in proton-proton collisions at $\sqrt{s}$ = 7 TeV
• Di-electron production from vector mesons with medium modifications in heavy ion collisions
• Transverse momentum spectra of dileptons at NA60
• Elliptic flow of thermal dileptons as a probe of QCD matter
• Observing many body effects on lepton pair production from low mass enhancement and flow at RHIC and LHC energies
• The low and intermediate mass dilepton and photon results
• Radial Flow from Electromagnetic Probes and Signal of Quark Gluon Plasma
• Dielectron Azimuthal Anisotropy at mid-rapidity in Au+Au collisions at $\sqrt{s_{{}_{NN}}}=200$ GeV
• Muon pairs from In+In collision at SPS energy
• Measuring radial flow of partonic and hadronic phases in relativistic heavy ion collision
• Thermal photon to dilepton ratio in ultra-relativistic heavy ion collisions
• Letter of Intent: the NA60+ experiment
• Dielectron production in 200 GeV p+p and Au+Au collisions at STAR
• The di-lepton physics program at STAR
• Thermal dileptons in high-energy nuclear collisions
• Thermal Dimuon Emission in In-In at the CERN SPS
• Dileptons and Direct Photons at SPS