Transcript Photons and Jets from the first year of ALICE A. Marin, for the ALICE

Photons and Jets from the first year
of ALICE
A. Marin,
for the ALICE Collaboration
DPG Spring Meeting 2011 , Münster (Germany)
[email protected]
1
Outline
 The ALICE experiment
 The 2010 data sample
 Physics results in pp
 Photon physics
 Jets
 First results in PbPb
DPG Spring meeting 2011, Münster (Germany)
[email protected]
2
ALICE:The dedicated HI Experiment
Size: 16 x 26 meters
Weight: 10,000 tons
Detectors: 18 3
DPG Spring meeting 2011, Münster (Germany)
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3
ALICE Detector Installation 2009-2010
ALICE Status
Complete:
ITS, TPC, TOF, HMPID,
FMD, T0, V0, ZDC,
Muon arm, Acorde
PMD, DAQ
Partial installation:
PHOS(3/5)
7/18 TRD
2-4/6 EMCAL
~ 50% HLT
DPG Spring meeting 2011, Münster (Germany)
[email protected]
P. Kuijer
4
4
The 2010 data sample
•p+p@7TeV: >800M MB, >100M m triggers, >25M high multiplicity
•[email protected]: ~30M nuclear collisions
DPG Spring meeting 2011, Münster (Germany)
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5
LHC: Entering a new regime
C W Fabjan 2008 J. Phys. G: Nucl. Part. Phys. 35, 104038
Cross-sections of interesting
probes expected to increase by
factors
~ 10 ( cc ) to
~ 102 ( bb ) to
~ > 105 (very high pT jets) ;
Hard probes of the medium
accessible at LHC
Direct photons are abundantly
produced at LHC
DPG Spring meeting 2011, Münster (Germany)
[email protected]
6
Photon physics in ALICE
 Measurement of p0 and h mesons in pp@7TeV and [email protected]




Highest energy available in lab
Test of pQCD cross section predictions
(HK 22.2, HK 22.3)
Reference data for PbPb
Main source of background in direct photon/heavy flavour electron measurement
 Measurement of Direct photons (not from decays) in pp@7TeV and
[email protected]




Highest energy available in lab
Test of pQCD cross section predictions
Reference data for PbPb
PbPb: hard processes in QGP medium, thermal properties of early phase
 g-Jet (g-hadron)
 Study quark energy loss in the medium
 Fragmentation function: Ejet ~ Eg
DPG Spring meeting 2011, Münster (Germany)
[email protected]
7
p0 and h reconstruction
pp  p0 + Xn
gg
e+
e+ e- e+ e-
(mp0 = 0.135 GeV/c2, BR = 0.988)
pp  h + Xn
gg
e-
e+ e- e+ e-
(mh = 0.548 GeV/c2, BR = 0.393)
g
Y
X
3 independent measurements:
Conversions, PHOS, EMCAL
DPG Spring meeting 2011, Münster (Germany)
[email protected]
run 104792, event 2248
8
V0 : Secondary vertex reconstruction
Reconstruction of (K0S,L, L ) converted photons in material (Z) gZ ge+e-Z
For analysis:
Package for fitting decay
particles based on the Kalman Filter
Specific energy loss in the TPC
-3sdE/dx<dE/dx-dE/dx(e)<+5s dE/dx
p rejection for p>1GeV, dE/dx > dE/dx(p)
m(g)=0
constrain to vertex
c2(g) < 30
Strict cut for material studies
DPG Spring meeting 2011, Münster (Germany)
[email protected]
9
Photons from pair conversions:
g-ray image of ALICE
converted photons in material (Z): gZge+e-Z
ALICE material budget (11.4% X0) agrees
within +3.4,-6%
with its implementation in GEANT simulations
DPG Spring meeting 2011, Münster (Germany)
[email protected]
10
p0 and h mesons @ 7TeV
M g 1g 2  2 Eg 1 Eg 2 (1  cos  g 1g 2 )
p0
h
DPG Spring meeting 2011, Münster (Germany)
[email protected]
11
Data 7 TeV: p0 invariant mass in pt bins
Combinatorial bck using mixed events Mgg 0.17-0.3 GeV/c2 for normalization
Very low pt reached with the conversion method
DPG Spring meeting 2011, Münster (Germany)
[email protected]
12
Data 7TeV: h invariant mass in pt bins
Mgg 0.6-0.7 GeV/c2 for normalization
DPG Spring meeting 2011, Münster (Germany)
[email protected]
13
Raw yields. Reconstruction efficiency
With 9.5 x 107 Minimum Bias collisions:
p0 measured in 0.4 GeV/c < pt < 7GeV/c
h measured in 0.6 GeV/c < pt< 6 GeV/c
DPG Spring meeting 2011, Münster (Germany)
[email protected]
14
Differential p0 invariant yield
Differential p0 invariant yield measured
in pp collisions@7 TeV
DPG Spring meeting 2011, Münster (Germany)
[email protected]
15
Comparsion to NLO
NLO predictions
from W. Vogelsang
s pp=70mb used
New ALICE
measurement
s pp= 62.3±0.4(stat)
±4.3(syst.) mb
Method and calculations described in:
[1] F. Aversa et al., Nucl. Phys. B327, 105 (1989).
[2] B. Jäger et al., Phys. Rev. D67, 054005 (2003).
[3] D. de Florian, Phys. Rev. D67, 054004 (2003).
DPG Spring meeting 2011, Münster (Germany)
[email protected]
16
h/p0 ratio
The h/p0 ratio is measured in pp collisions @7TeV
for 0.6 GeV/c <pt<6 GeV/c.
In agreement with Pythia expectations and with
the world data measured in hadron-hadron collisions,
taken from Phys. Rev.C 75 0224909 (2007).
DPG Spring meeting 2011, Münster (Germany)
[email protected]
17
Direct photons at RHIC
PHENIX Coll.:Phys. Rev. Lett. 94, 232301 (2005)
PHENIX Coll.:Phys. Rev. Lett. 104 (2010) 132301
•pp consistent with NLO pQCD calculations
•AuAu larger than calculation for pT<3.5GeV/c
Excess exponential in pT
T=221± 23(stat)±18(sys) MeV
DPG Spring meeting 2011, Münster (Germany)
[email protected]
18
How many direct photons @ LHC?
Measurement was done at RHIC
... but more difficult at LHC
g/p0 = 0,01-0,1 for pT > 20 GeV/c
We need a good distinction
direct/decay g
Cern Yellow Report 2004-009, hep-ph/0311131
DPG Spring meeting 2011, Münster (Germany)
[email protected]
19
Photon decay cocktail
Work in progress
DPG Spring meeting 2011, Münster (Germany)
Work in progress
[email protected]
20
Jets
HK 22.4,
HK 22.5, HK 22.6,
HK 22.7, HK 40.9
DPG Spring meeting 2011, Münster (Germany)
[email protected]
21
Jet properties from di-hadron
correlations
Near side (intra-jet):
“Single” jet properties, fragmentation
'near'side
r
jT
'away' side
UE
Away side (inter-jet):
Di-jet, hard scattering, properties,
KT effects
Trigger particle
DPG Spring meeting 2011, Münster (Germany)
[email protected]
22
Correlation functions:√s= 0.9 and 7 TeV
Large statistics allows up to 30 GeV/c of the trigger particle
DPG Spring meeting 2011, Münster (Germany)
[email protected]
23
Jet properties from di-hadron
correlations
Measure of average transverse
momentum of fragmentation
products relative to jet axis
jT2
jT2
900 GeV
7 TeV
= 678  12 MeV/c
 673  5 MeV/c
All measurements agree
within the errors
Expected independence
on trigger particle
pT and √s confirmed
r
jT
DPG Spring meeting 2011, Münster (Germany)
[email protected]
24
Away side width and kT
zt
xˆh
kT2 
partonic
1
xh
2
 jTy2 (1 + xh2 )
pout
hadronic/measured
√(p/2)x√<kT2>
ALICE
preliminary
ALICE
preliminary
Confirmed expected increase of
momentum imbalance of parton pair
DPG Spring meeting 2011, Münster (Germany)
[email protected]
25
Full Jet reconstruction in ALICE in 2010
 Using central tracking detectors
 Charged jet reconstruction only
 Different jet finders
 UA1 cone algorithm
 FASJET Suite (kT, anti-kT, SIScone)
 Cone size 0.4
 Comparison to PbPb
 Maximum efficiency of central barrel |hjet|<0.5
 Jet finding in PbPb
 Low momentum cut off (150 MeV)
pT , jet  pTrec, jet    A jet  s  A jet
DPG Spring meeting 2011, Münster (Germany)
[email protected]
26
Raw Jet Spectrum: p+p @7TeV
Jets |h|<0.5
Tracks |h|<0.8
Jet spectrum with charged particles
safely reconstructed out to 70 GeV
DPG Spring meeting 2011, Münster (Germany)
[email protected]
27
First PbPb collisions in ALICE
0-5% cent: dNch/dh ~ 1584 ± 4 (stat) ± 76 (syst)
DPG Spring meeting 2011, Münster (Germany)
[email protected]
28
"Jet quenching" from charged
particle spectra
HK22.1
Suppression of high pt particles ( ~ leading jet fragments)
Rising with pt !
Accuracy limited by pp reference
=> need pp at 2.76 TeV !
ALICE, Phys. Lett. B 696 (2011) 30
DPG Spring meeting 2011, Münster (Germany)
[email protected]
29
[email protected] ATeV: p0 invariant mass
in pt bins
p0 can be reconstructed from 0.4 GeV/c to 12 GeV/c
DPG Spring meeting 2011, Münster (Germany)
[email protected]
30
p0 raw yield vs pt
First step towards p0 RAA
DPG Spring meeting 2011, Münster (Germany)
[email protected]
31
Jet quenching from High pT
correlations
Clear away side correlation in p+p @7TeV
Df
Away side correlation in central Pb-Pb washed out up to pT,trig>10GeV
DPG Spring meeting 2011, Münster (Germany)
[email protected]
32
Raw anti-k T Jet Spectrum in Pb+Pb
Event-by-event background subtracted,not unfolded.
Effect of background fluctuations/smearing apparent.
Detailed correction currently prepared.
DPG Spring meeting 2011, Münster (Germany)
[email protected]
33
Conclusions and outlook
 ALICE took data succesfully during the 2010 run for pp
and PbPb collisions
 p0 (and h) mesons differential yields measured in pp
collisions at 7 TeV.
 Basic ingredients for a direct photon measurement
 Jet properties measured in pp collisions from di-hadron
correlations
 Full jet reconstruction is done using different algorithms.
Work is still ongoing to apply all corrections
 High pt suppresion of charged particles is observed in
central PbPb collisions. Jet quenching at LHC
 Uncorrected p0 pt spectrum and jet pt spectrum have
been shown. Work is ongoing to obtain RAA(p0) and fully
corrected jet pt spectrum
DPG Spring meeting 2011, Münster (Germany)
[email protected]
34
ALICE TALKS
PV 5.1
HK
HK
HK
HK
HK
HK
HK
HK
HK
HK
HK
ALICE in Wonderland: first results from the ALICE experiment at the LHC — •Peter
Braun-Munzinger
7.8
Online Drift Velocity Calibration with the Laser System of the ALICE-TPC — •Mesut
Arslandok
12.9 Central diffractive meson production in p+p collisions at √s=7 TeV at the ALICE
experiment — •Xianguo Lu
14.8 The SysMES Inventory Module in the ALICE HLT Cluster — •Jochen Ulrich, Camilo Lara,
Stefan
Böttger, Timo Breitner, Pierre Zelnicek, and Udo Kebschull
14.9 Virtual Machine Scheduling in the ALICE HLT — •Stefan Boettger, Jochen Ulrich, Camilo
Lara,
Timo Breitner,
Pierre Zelnicek, and Udo Kebschull
15.3 Korrelationen von schweren Quarkteilchen in hochenergetischen Kern-Kern-Reaktionen —
•Andre
Mischke
15.4 Performance Studies for the Measurement of ψ′ via the Decay Channel ψ‵ → J/ψ π+π−
→ e+e− π+π− with
the ALICE Detector — •Moritz Pohl, Christoph Blume, and
Frederick Kramer
15.6 Messung von Dielektronen niedriger Masse mit dem ALICE Detektor in Proton-Proton und
Blei-Blei Kollisionen — •Markus Konrad Köhler
20.5 A Common Read-Out Receiver Card for ALICE DAQ and HLT — •Heiko Engel and Udo
Kebschull
22.1 Suppression of Charged Particle Production at Large Transverse Momentum in Central
Pb−Pb
Collisions at √sNN=2.76 TeV — •Jacek Otwinowski
22.2 Rekonstruktion von π0 und η Mesonen mittels Photon Konversionen in ALICE in Proton Proton
Kollisionen am CERN LHC — •Friederike Bock
22.3 Rekonstruktion von π0-Mesonen mittels Photon-Konversionen mit ALICE in PbPb-Kollisionen
am CERN LHC — •Radoslav Rusanov
DPG Spring meeting 2011, Münster (Germany)
[email protected]
35
ALICE TALKS
HK 22.4
HK
HK
HK
HK
HK
HK
HK
HK
HK
HK
HK
Jet and High-pT Measurments with the ALICE Experiment at the LHC — •Bastian Bathen,
Tom Dietel, and
Christian Klein-Bösing
22.5 Quark and gluon composition of jets in proton-proton collisions at √s = 7 TeV with ALICE
at the LHC — •Hermes Leon Vargas
22.6 Two- and Three-Particle Jet-Like Correlations in the ALICE Experiment at the LHC —
•Jason Glyndwr Ulery
22.7 Charged Particle Momentum Distribution in Jets in ALICE — Bastian Bathen, •Oliver Busch,
and Christian Klein- Bösing
22.8 ALICE TRD GTU Online Tracking and Trigger Performance in pp and PbPb Collisions —
•Felix Rettig, Stefan
Kirsch, and Volker Lindenstruth
22.9 Beauty and beauty-jet measurement via displaced vertices with ALICE in p+p collisions at
√s = 7 TeV — •MinJung
Kweon
28.1 Alice HLT TPC Tracking of PbPb-Events on GPU and CPU — •David Rohr and Sergey
Gorbunov
28.2 Development of a trigger system to test and calibrate ALICE-TRD super-modules —
•Jonas Anielski
39.20 Ein Driftgeschwindigkeitsmonitor für den ALICE TRD — •Friederike Poppenborg
39.57 ALICE Grid Computing at the GridKa Tier-1 center — •Christopher Jung and Kilian
Schwarz
40.1 Measurement of transverse momentum spectra of identified hadrons from pp and PbPb
collisions with the ALICE
experiment — •Alexander Kalweit
40.2 Neutral strange hadron reconstruction in pp and PbPb collisions at LHC energies — •Simone
Schuchmann
DPG Spring meeting 2011, Münster (Germany)
[email protected]
36
ALICE TALKS
HK 40.3
Measurement of nuclei and antinuclei with the ALICE experiment at the LHC — •Nicole
Martin and Alexander Kalweit
HK 40.5 Event-by-event fluctuations of mean transverse momentum in pp collisions at √s = 900 GeV
and 7 TeV measured by the ALICE experiment — •Stefan Heckel
HK 40.6 Analyse der Pionenquelle durch HBT-Interferometrie mit ALICE — •Johanna Gramling
HK 40.7 Analyse von Pseudorapiditäts-Dichtekorrelationen mittels Multiplizitätsverteilungen in ppund PbPb-Kollisionen mit
ALICE — •Maren Hellwig
HK 40.8 Mini-Jet Activity as Function of Charged Multiplicity — •Eva Sicking
HK 40.9 Underlying Event measurement in pp collisions with the ALICE detector — •Sara Vallero
for the ALICE collaboration
HK 40.10 Results of the Quality Assurance for the High Level Trigger Applications for the ALICE
TRD — •Theodor Rascanu
HK 61.1 vom ALICE Tier2 zum FAIR Tier0 - Computing at GSI — •Kilian Schwarz
HK 63.2 Photons and Jets from the First Year of ALICE — •Ana Marin
HK 64.1 Measurement of the J/ψ Production Cross Section in pp Collisions at √s=7 TeV with ALICE
at the LHC and
Perspectives for PbPb Collisions — •Frederick Kramer, Ionut Arsene,
Christoph Blume, Julian Book, Anton
Andronic, WooJin
J. Park, and Jens Wiechula
HK 64.2 Electrons from heavy flavour decays with the ALICE experiment in proton-proton collisions
at √s= 7TeV — •Raphaelle Bailhache
HK 64.3 Messung des Wirkungsquerschnitts von Hadronen mit schweren Quarks in Proton-Proton
Kollisionen mit
dem ALICE Experiment — •Fasel Markus
DPG Spring meeting 2011, Münster (Germany)
[email protected]
37
ALICE TALKS
HK 64.4
HK 64.5
HK 64.6
Messung der Produktion schwerer Quarks in Pb+Pb Kollisionen mit dem ALICE
Detektorsystem — •Yvonne
Pachmayer
Reconstruction of open charm in the decay channel D0→K−π+ with ALICE —
•Robert Grajcarek
Open charm production in the D*+ → D0 π+ decay channel with ALICE — •Yifei
Wang
DPG Spring meeting 2011, Münster (Germany)
[email protected]
38
ALICE COLLABORATION
DPG Spring meeting 2011, Münster (Germany)
[email protected]
39
39
Backup slides
DPG Spring meeting 2011, Münster (Germany)
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40
Differential invariant cross section
PHOS + Conversions
DPG Spring meeting 2011, Münster (Germany)
[email protected]
41
Background density
Strong change within one centrality bin.
Better correlation in multiplicity
DPG Spring meeting 2011, Münster (Germany)
[email protected]
42
Testing Background Fluctuations
Embedding of single tracks: δ-probe for jet finding at random position
Random Cones: Sum in circular area at random position
(excluding the two leading jets)
DPG Spring meeting 2011, Münster (Germany)
[email protected]
43
Charged
Jets
10-20% peripheral
168 GeV
192 GeV
Jet quenching
jet E ->
jet E’ (=E-DE) + soft gluons (DE)
Df
Dh
0-10% central
102 GeV
47 GeV
DfDPG Spring meeting 2011, Münster (Germany)
[email protected]
Dh
44
Charged particle multiplicity density
dNch/dh ~ 1584 ± 4 (stat) ± 76 (syst)
•somewhat on high side of expectations
•growth with √s faster in AA than pp
PRL 105, 252301 (2010)
DPG Spring meeting 2011, Münster (Germany)
[email protected]
45
Centrality dependence of Charged
particle multiplicity density
Centrality dependence of the
multiplicity is found very similar
at √sNN=2.76 and √sNN=0.2TeV.
Scale different by a factor 2.1
DPG Spring meeting 2011, Münster (Germany)
[email protected]
PRL 106, 032301 (2011)
46
Un-triggered CF
DPG Spring meeting 2011, Münster (Germany)
[email protected]
47
DPG Spring meeting 2011, Münster (Germany)
[email protected]
48
Probing Hot QCD Matter with hard probes
Hard Probes:
“highly penetrating observables (particles, radiation)
used to explore properties of matter that cannot be viewed directly!”
High pT particles: p0,h, direct g
Jets
p+p collisions provide a baseline
DPG Spring meeting 2011, Münster (Germany)
[email protected]
49
Hard probes
p+p:
• parton scattering  fragmentation  jet
• can be calculated in perturbative QCD
• collinear factorization
hadrons
c
b
a
A+A:
• partons traversing medium lose energy
hadrons
gluon radiation, elastic collisions
• energy loss different for g, light/heavy quarks
(color factor, dead cone effect)
d
leading
particle
Goal: Use in-medium energy loss to
measure medium properties
h
ds pp
Dh0/ c
2
2 ds
 K   dxa dxb f a ( xa , Q ) f b ( xb , Q )
(ab  cd )
2
ˆ
dyd pT
dt
pzc
abcd
X.-N. Wang, M. Gyulassy, Phys. Rev. Lett. 68 (1992) 1480
Parton distribution function
measured in DIS
initial state (saturation?)
DPG Spring meeting 2011, Münster (Germany)
[email protected]
Matrix element Fragmentation function
pQCD
e +e final state (energy loss?)
50
RAA for p0, h and direct g
RAAg~=1
0,h
RAAp
~=0.2
The hadron spectra at RHIC from p+p, Au+Au and d+Au collisions establish
existence of parton energy loss from strongly interacting,
dense QCD matter in central Au-Au collisions
^ = 4 – 13 GeV2 / fm
<q>
dNg/dy~1400+-200
S. Bass et al. PRC79 (2009) 024901
https://wiki.bnl.gov/TECHQM/index.php/Main_page
Theory-Experiment Collaboration on Hot Quark Matter
DPG Spring meeting 2011, Münster (Germany)
[email protected]
51
jT systematics: formulae
If trigger and associated hadrons fragment independently:


s  t  a   t    + a     arcsin
2
2
N
2
2
j yt
2
pTt
+ arcsin
2
j ya
pTa
First approximation: arcsin(x)~x and because <jT2>=2<jy2>:
 1
1
2s  j  2 +
2
p
p
Ta
 Tt
2
N
2
T




jT2 
2s N
1
1
+
2
2
pTt
pTa
Two approximations follow:
(1) <1/p2>~1/<p>2
(2) <p> is taken from inclusive (rather than jet) spectrum
2
T
j
 2s N
pTt
pTt
DPG Spring meeting 2011, Münster (Germany)
[email protected]
2
pTa
+ pTa
2
52
52
Why photon-tagged jets?

Medium effects redistribute (q
^ L ) the parton
energy, Ejet, inside the hadron jet
(multiplicity, jT).

Redistribution can be best measured with the
Fragmentation Function... If we know Ejet.

HI environment hinders precise
If we measure Eg ≈ Ejet
1/Njet dN/d
reconstruction of Ejet.
Borghini,Wiedemann, hep-ph/0506218
Quenching increases
low-pT particles
E
p
1
z
  ln( )  ln( )
Quenching reduces
high-pT particles
DPG Spring meeting 2011, Münster (Germany)
[email protected]
53
Photon Detection in ALICE
 PHOS (1000 x 0.24 in h
(PHOS/CentralBarrel=0.037)
 high resolution (energy and spatial)
 small coverage
 EMCAL
 larger coverage: 120O x 1.4 in η (EMCAL/CentralBarrel=0.26)
 coarser spatial resolution than PHOS
 available in 2010
 gZ→ e+e- Z Conversions (Central Barrel)
 large coverage: 360O x 1.8 (2.4) in h (Conversion/CentralBarrel=0.08)
 low conversion probability : 8% (16%)
DPG Spring meeting 2011, Münster (Germany)
[email protected]
54
Interaction of photons with matter
•Photoelectric effect
•Compton scattering
•Pair production: Eg>1.02MeV
•Electromagnetic Calorimeters:
The complete photon energy is
deposited in the detector (electromagnetic shower)
•Photon measurement via pair conversions:
Determine photon momentum and direction by measuring e+/efrom a single g conversion in tracking detectors
ALICE ( ITS+TPC+TRD)
DPG Spring meeting 2011, Münster (Germany)
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55
Direct photon sources
Why? Do not interact strongly.
Carry information about the early state.
q
γ
g
q
q
γ
q
qg Compton Scattering
Bremsstrahlung,
fragmentation
qq Annihilation
q
g
γ
g
γ
q
g
g
q
q
Thermal photons from QGP and hadron gas
Photons from Jet re-interaction in the medium
...in a large background from p0 and h decays
DPG Spring meeting 2011, Münster (Germany)
[email protected]
56
Photon Production: different sources
Turbide, Gale, Jeon, and Moore
PRC (2004) 014906
Photons are abundantly produced at LHC
Jet-photon conversion in the plasma dominates 8<pT<14 GeV
Prompt hard NN scattering dominant for p T>20GeV at LHC
DPG Spring meeting 2011, Münster (Germany)
[email protected]
57
Data 7 TeV: p0 invariant mass in pt bins
Combinatorial bck using mixed events Mgg 0.17-0.3 GeV/c2 for normalization
Very low pt reached with the conversion method
DPG Spring meeting 2011, Münster (Germany)
[email protected]
58
Data 7TeV: h invariant mass in pt bins
Mgg 0.6-0.7 GeV/c2 for normalization
DPG Spring meeting 2011, Münster (Germany)
[email protected]
59
Raw yields. Reconstruction efficiency
With 9.5 x 107 Minimum Bias collisions:
p0 measured in 0.4 GeV/c < pt < 7GeV/c
h measured in 0.6 GeV/c < pt< 6 GeV/c
DPG Spring meeting 2011, Münster (Germany)
[email protected]
60
Differential p0 invariant yield
Differential p0 invariant yield measured
in pp collisions@7 TeV
DPG Spring meeting 2011, Münster (Germany)
[email protected]
61
h/p0 ratio
The h/p0 ratio is measured in pp collisions @7TeV
for 0.6 GeV/c <pt<6 GeV/c.
In agreement with Pythia expectations and with
the world data measured in hadron-hadron collisions,
taken from Phys. Rev.C 75 0224909 (2007).
DPG Spring meeting 2011, Münster (Germany)
[email protected]
62
[email protected] ATeV: p0 invariant mass
in pt bins
p0 can be reconstructed from 0.4GeV/c to 12GeV/c
DPG Spring meeting 2011, Münster (Germany)
[email protected]
63
p0 raw yield vs pt
First step towards p0 RAA
DPG Spring meeting 2011, Münster (Germany)
[email protected]
64