In-medium Spectral Functions in a Coarse-Graining Approach

Abstract

We use a coarse-graining approach to extract local thermodynamic properties from simulations with a microscopic transport model by averaging over a large ensemble of events. Setting up a grid of small space-time cells and going into each cell's rest frame allows to determine baryon and energy density. With help of an equation of state we get the corresponding temperature $T$ and baryon-chemical potential ${\mu }_{\mathrm{B}}$. These results are used for the calculation of the thermal dilepton yield. We apply and compare two different spectral functions for the $\rho$ meson, firstly a calculation from hadronic many-body theory and secondly a calculation from experimental scattering amplitudes. The results obtained with our approach are compared to measurements of the NA60 Collaboration. A relatively good description of the data is achieved with both spectral functions. However, the hadronic many-body calculation is found to be closer to the experimental data with regard to the in-medium broadening of the spectral shape.

5 pages, 1 figure; Contribution for FAIRNESS 2014 proceedings

References in corpus (22)

• Microscopic Models for Ultrarelativistic Heavy Ion Collisions
• Relativistic Hadron-Hadron Collisions in the Ultra-Relativistic Quantum Molecular Dynamics Model (UrQMD)
• Thermal dilepton rate and electrical conductivity: An analysis of vector current correlation functions in quenched lattice QCD
• Low-Mass Dileptons at the CERN-SpS: Evidence for Chiral Restoration?
• Dilepton Radiation at the CERN Super Proton Synchrotron
• Hadrons in strongly interacting matter
• Comprehensive Interpretation of Thermal Dileptons at the SPS
• 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
• Properties of $\rho$ and $\omega$ Mesons at Finite Temperature and Density as Inferred from Experiment
• Particle ratios at RHIC: Effective hadron masses and chemical freeze-out
• Dilepton production in proton-nucleus and nucleus-nucleus collisions at SPS energies
• Rho properties in a hot meson gas
• A Microscopic Calculation of Photoabsorption Cross Sections on Protons and Nuclei
• Momentum Dependence of the Pion Cloud for Rho Mesons in Nuclear Matter
• Thermal Dileptons from Hot and Dense Strongly Interacting Matter
• Dileptons and Photons from Coarse-Grained Microscopic Dynamics and Hydrodynamics Compared to Experimental Data
• Ideal Hydrodynamics for Bulk and Multistrange Hadrons in $\sqrt{s_{NN}}$=200\,AGeV Au-Au Collisions
• Production and evolution path of dileptons at HADES energies
• A coarse-graining approach for dilepton production at SPS energies
• UrQMD-2.3 - Changes and Comparisons
• Dilepton Production in Transport Calculations and Coarse-Grained Dynamics

Cited by in corpus (1)

• Dilepton production and reaction dynamics in heavy-ion collisions at SIS energies from coarse-grained transport simulations