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Relativistic Heavy Ions Experiment IV. Photons and Neutral Mesons. Time Evolution of a Heavy Ion Collision. Photon Sources in A+A Collisions. Hard direct Photons. E.M. Bremsstrahlung. Prompt Photon Sources in p+p Reactions. Prompt Photons. Photons from Jet-Fragmentation.
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Relativistic Heavy IonsExperiment IV Photons and Neutral Mesons
Hard direct Photons E.M. Bremsstrahlung Prompt Photon Sources in p+p Reactions
Prompt Photons Photons from Jet-Fragmentation Fraction of Prompt Photons in p+p Reactions
Thermal photons from the hot medium Jet-photon conversion in the medium Additional Photon Sources in A+A
Theoretical Expectation in A+A Turbide, Rapp, Gale, Phys. Rev. C 69 (014903), 2004
Prompt and Thermal Photons in Pb+Pb at 158AGeV kt-broadening + Ti = 205MeV no kt-broadening + Ti = 270MeV Turbide, Rapp, Gale, Phys. Rev. C 69 (014902), 2004
Theoretical Descriptions and Initial Temperatures Ti Turbide, Rapp, Gale (Phys.Rev.C69:014903,2004 ) QGP + HG + pQCD with kT Ti = 205 MeV, t0 = 1 fm/c QGP + HG + pQCD without kT Ti = 250 - 270 MeV, t0 = 0,5 fm/c Renk (Phys.Rev.C67:064901,2003) QGP + HG + pQCD 250 < Ti < 370 MeV,0,5 < t0 < 3 fm/c Svrivastava (nucl-th/0411041) QGP + HG + pQCC(Bjorken hydro) Ti = 335 MeV, t0 = 0,2 fm/c Huovinen, Ruuskanen, Räsänen (Nucl. Phys. A 650 (227) 1999) QGP + HG + pQCD(Non-boost inv. hydro) Ti = 214 - 255 MeV Pure HG + pQCD(Non-boost inv. hydro) Ti = 213 - 234 MeV
Prompt Photons in Au+Au, s = 200GeV p+p measurement scaled with Ncoll
invariant mass of virtual photon form factor invariant mass of Dalitz pair e+ Compton e- g* q g q phase space factor p0 e+ g* e- Direct Photon Measurement via Virtual Photons g
S/B=~1 g g h h p0 p0 Direct Photon Measurement via Virtual Photons
Rdirect S/B=~1 g g h h calculated from Dalitz formula Rh p0 Rp0 p0 measured with EMCal measured ÷ Rdata Direct Photon Measurement via Virtual Photons