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Dileptons and Photons . K. Dusling and I . Z. BNL 09. Outline. Motivation Rates Evolution Experiments. NA45: 95. NA60: 03 . Phenix: 07 . Rate: Formally . Acceptance: NA60 vs PHENIX. Hadronic Rates. Dilepton Production. l +. l +. l -. l -. Resonance Gas: J= ρ+ρ ’+.
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Dileptons and Photons K. Duslingand I. Z. BNL 09
Outline • Motivation • Rates • Evolution • Experiments
Dilepton Production l+ l+ l- l-
Resonance Gas: J=ρ+ρ’+.. +2+3, …-Pi, +2+3, …-K +2+3, …-N Expand in Stable Hadrons
+ … + … Many Feyman Graphs: + … +
In Practice: NF=2 Chiral Limit and zero-mtm pion:
VA Mixing=LxR Restoration? Dey, Eletsky, Ioffe 96
Expansion Parameter: = 0 Dilute!
Data : e+e- Decay .
1 Nucleon Final State = + 1 Loop ChPT N- Transition
Input at the Photon Point N background
VA Mixing in T=180 MeV
a1a1 VA Mixing in T=150 MeVμb=225 MeV
wQGP: l+ l+ l- l-
wQGP: LPM Effect: Aurenche et al 02
wQGP: γ Collinear Enhancement+ LPM Effect : Arnold, Moore, Yaffe 01
sQGP: OPE Hansson and Zahed 91
Hydro Parameters SPS, RHIC and LHC
Thermal Freeze-out Cooper-Frye
Chemical Freezeout: Fireball cools faster x Rates higher = w/μπ !
NA60 dimuons : Upshots • Hadronic emission dominant: VA mixing • Partonic emission small: tiny QGP • Blue shifted spectra (M=rho): small Lh?
PHENIX Dusling+Z 07 Dusling+Z 09
PHENIX DI-electrons : Upshots • Hadronic large but Filtered: M<500 MeV • Partonic large and dominant: 100<M<250 !! • Hadronic large and dominant: M=ρ-ω-φ • Non-thermal emission: 300<M<500 MeV. Another DLS-like puzzle?
Versus Kinetic Turbide, Rapp, Gale 04; Liu, Rapp 07
WA98 0<qT (GeV) <4 0<qT (GeV)<0.8 N:x2
Rates at RHIC RHIC1 RHIC2
PHENIX RHIC1 RHIC2
Systematics of the Extrapolation 15% Systematics!