Dilepton Spectroscopy of QCD Matter at Collider Energies
Figure 2
Dilepton rates from hot QCD matter in the isovector () channel. (a) Effective hadronic Lagrangian plus many-body approach for the in-medium spectral function (solid line) at a temperature and chemical potential characteristic for chemical freezeout at full SPS energy; the effects of in-medium pion-cloud (long-dashed line), baryon resonances (dash-dotted line), and meson resonances (short-dashed line) are shown separately along with the rate based on the vacuum spectral function (dotted line). (b) Comparison of free and in-medium hadronic and partonic calculations at temperature MeV and small baryon chemical potential characteristic for RHIC and LHC conditions; the free and in-medium hadronic rates are based on [35, 36]; the “lat-QGP” rates (2 short-dashed lines) are based on fits to the lQCD rate with extensions to finite 3-momentum utilizing perturbative photon rates (see Section 2.2 for details).
