2011 QCD and High Energy Interactions - Rencontres de Moriond ...

is significantly larger than both p+p cases, which is not surprising due to the clear ridge and
shoulder structure. This enhancement is much larger than simply quenching the away-side
jet can provide, which means there must be some other source which contributes to this strong
enhancement. At the current stage, we do not know what the main sources for this enhancement
is. Also notable is that the C4 term seems to have some excess compared to p+p.
In conclusion, PHENIX has measured the higher harmonics, v2, v3 and v4 in various centrality
and pT combinations with two different methods. The measured v3 is described well by
hydrodynamical calculations. When studying the Fourier spectra of the jet functions (with v2
shape background subtracted) in Au+Au compared to p+p, we see that the third harmonic, C3,
is significantly larger in Au+Au, which indicates some source other than the jet contributes to
this anomalous enhancement.
References
n
C
PHENIX preliminary
JF( Δφ)=
Σ(C
cos(nΔφ))
n
0.08
0.06
0.04
0.02
0
Au+Au, s =200GeV
NN
inc. γ-h
(v
2.0-3.0x1.0-2.0 GeV/c
00-20%
20-40%
40-60%
60-90%
pp, full
pp, near only
subtracted)
2
0 2 4 6 8
Figure 3: Fourier spectra of Au+Au jet functions in different centralities and compare with p+p.
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n