jet quenching review i
DESCRIPTION
Jet quenching review I. Main Review article; hep-ph/0406201 : Leading-particle suppression in high energy nucleus-nucleus collisions A. Dainese, C. Loizides and G. Paic. Su Houng Lee. Other Main References: - PowerPoint PPT PresentationTRANSCRIPT
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Su Houng Lee
Jet quenching review I Jet quenching review I
Main Review article; hep-ph/0406201
: Leading-particle suppression in high energy nucleus-nucleus collisions
A. Dainese, C. Loizides and G. Paic. Other Main References:
1. The Landau-Pomeranchuck-Migdal effect in QED, Baier, Dokshitzer, Mueller, Peigne, Schiff (BDMPS), NP B478 (1996) 577
2. Radiative energy loss of high energy quarks and gluons in a finite-volume quark gluon plasma, BDMPS, NPB 483 (1997) 291.
3. Gluon radiation off hard quarks in a nuclear environment: opacity expansion, U. Wiedemann, NPB 588 (2000) 303
4. Calculating quenching weights, Salgado, Wiedemann, PRD 68, 014008 (2003)
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Ject quenching
An important parameter to be understood q̂
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Section 2
Parton energy loss and collision goemetry
+My personal review
[email protected]@phya.snu.ac.kr
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Basics: fast charged particle scattering from scattering centers
10 Ep
2p
1p1x
2x
1q 2q
cx1
cx2cnx
nq
np
0110
11404 |)()()().....()()(
!| pxxAxxdxxAxxdn
ipS nnnn
n
n yyyy
223
3 )](exp[
)2()(
p i
ciiii
i q
xxiqxdixA
n
i i
iin
i i
iN q
xiq
ip
pdppS
122
)(1
12
300
0 ]exp[)(
h s
s
1
2,
2,
22,, ),,,(
iii
TiziiTizii
ppq
ppEpppEp
h
h
iE
pEp
iE
pEp
Tizi
Tizi
2
,2
2,
,
2,
,
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n
i i
iin
i i
iN q
xiq
ip
pdppS
122
)(1
12
300
0 ]exp[)(
h s
s
22,1
2
2,
,
22,1
2,
,
4
1
2
1 ,
2
h
h
T
Tizi
T
Tizi
pEi
E
pEp
pi
E
pEp
n
i
n
inznziiziTiTi
n
iiiscatt zpzpizzpixqixqii
1
1
1)(,)1(,0)()1(,),(,
1)( )()( ssssss
22,1
21
221 )(
11
TpEpq
1. The high energy electron scatters successively on ordered scattering centers
2. As a consequence, the electron momenta are on shell
)1()1()( ...... sss zzz nn
hiE
pEp Ti
zi 2
2,
,
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Basics: fast charged particle radiating from scattering centers
10 Ep
2p
1p1x
2x
1q 2q
cx1
cx2cnx
nq
np
3q
cx3
),,( Tz kkk
2
12
)exp(n
iii iBd
d
dI pa
E
pkuzzu TjTj
n
jiiiiscattrad
,1
12 ,)(
2
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For QCD: Non-abelian nature
10 Ep
2p
1p1x
2x
1q 2q
cx1
cx2cnx
nq
np
3q
cx3
),,( Tz kkk
zkT
2
2
sizeQGPLq
qcenterscatteringdist
transfermediumT
,ˆ2
Two parameters characterizing the medium
cT L
LqLq
Lk
2
ˆ ˆ22Characteristic phase for coherent radiation
322
ˆ2
1ˆ
2 ,
2ˆ Lq
LqR
Lq c
c Change of variables typically to
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Some famous result for QCD
10 Ep
2p
1p1x
2x
1q 2q
cx1
cx2cnx
nq
np
3q
cx3
),,( Tz kkk
c
2
for 12
1
for 2
lim
pa
c
cc
Rs
R
C
d
dI
2
0
ˆ lim LqCCdd
dIE RscRs
RR
aa
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Section 3
Leading-particle suppression procedure
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Actual step I: Factorization formula
2
/
0,
2
,,,,0
2 )(ˆ)()(
j
jjh
yjjt
jXab
bbaajbagqqjbayt
h
z
zD
dydp
dxfxfdzdxdx
dydp
d
j
ss
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Step II: determination of parameters
0,2
b
0,
2
bz
For each parton
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Different parameterization
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Step III: determination of parameters
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Step IV: determination of parameters
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Section 4
Results
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Nuclear modification factor in Au-Au at 200 GeV - i
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Nuclear modification factor in Au-Au at 200 GeV - ii
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Nuclear modification factor in Au-Au at 200 GeV - iii
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Nuclear modification factor in Au-Au at 200 GeV - iv
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Back to back correlation
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Azimuthally-differential observables - i
Non negligible collective flow effect
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Azimuthally-differential observables - ii
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Nuclear modification factor in Au-Au at 62.4 GeV - i
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Extrapolation to the LHC (5.5 TeV)
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Section 5
Discussion
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High-energy partons from the surface
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High-energy partons from the surface
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Energy loss saturation
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Section 6
Conclusion
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Energy loss saturation
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SummarySummary