quarkonium physics in nuclear collisions @...
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Quarkonium physics in nuclear collisions @ LHC
by Martin Freudenberger
31.01.2008
Quarkonium physics in nuclear collisions @ LHC2/29
OutlineI. Introduction
II. Melting model and kinetic model
III. Statistical Hadronization Model
IV. RHIC data and predictions for LHC
V. Experiments @ LHC
Quarkonium physics in nuclear collisions @ LHC3/29
Introduction
• Formation of QGP at nucleon-nucleon collisions
• “Fingerprint” for QGP J/Ψ suppression / enhancement
• Different Models describing J/Ψ production• Satz – Matsui approach , Statistical
Hadronization model , kinetic model …
Quarkonium physics in nuclear collisions @ LHC4/29
Review
• Quarkonia = bound state of quark antiquark pair of heavy quarks e.g. J/Ψ
• No strong decay if mass of Quarkonia is less then combination of open charm mesons
Quarkonium physics in nuclear collisions @ LHC5/29
OutlineI. Introduction
II. Melting model and kinetic model
III. Statistical Hadronization Model
IV. RHIC data and predictions for LHC
V. Experiments @ LHC
Quarkonium physics in nuclear collisions @ LHC6/29
Review Melting Model
• Time Scales for QGP Formation and J / Ψformation of same order
• Debye screening of color charge deconfinement
• Deconfining radius smaller than hadron radius diffusion during lifetime of QGP
• Melting before T < TD with TD > 1.15 TC• Resent studies indicate TD = 2TC
Quarkonium physics in nuclear collisions @ LHC7/29
Widths of Charmonia in QGP• Estimated from mean free path length in
QGP λ = 1 / npσParton density np = 4.25 T3
J / Ψ Parton cross section σ = 2mbvrel of J / Ψ vs. Partons
in medium width Γ = vrel / λwith numerical values:Γ(T=300 MeV) = 320 MeV Γ(T=400 MeV) = 760 MeV
Quarkonium physics in nuclear collisions @ LHC8/29
Kinetic Model – Basic ideas
• Production of J / Ψ in the QGP through binding of independent quark antiquark pairs
• Centrality dependence due to impact parameter b
• Enhancement in J / Ψ production for central collisions at RHIC energies
Quarkonium physics in nuclear collisions @ LHC9/29
OutlineI. Introduction
II. Melting model and kinetic model
III. Statistical Hadronization Model
IV. RHIC data and predictions for LHC
V. Experiments @ LHC
Quarkonium physics in nuclear collisions @ LHC10/29
Statistical Hadronization Model• All Charm quarks produced in initial hard
collisions• Early produced Charmonia destroyed in
QGP• Number of charm quarks = const.• Input parametersi. Charm production cross sectionii. Temperature T , Baryochemical Potential
µB , and Volume VΔy=1
Quarkonium physics in nuclear collisions @ LHC11/29
Input Parameters• Up to Sqrt(s) = 200 GeV T ~ 160 MeV• µB decreases from 434 to 22 MeV• Volume at midrapidity rises continuously• For LHC:
Source: A. Andronic et al. arXiv:0711.0974v1 [hep-ph] 127
Source: A. Andronic et al. arXiv:0710.1851v1 [nucl-th]
Quarkonium physics in nuclear collisions @ LHC12/29
Input parameters
Sqrt(sNN) (GeV) 17.3 200 5500T (MeV) 170 170 170µB (MeV) 253 27 1
3.4][
1
][1270GeVs
MeV
NNB
+
=μ
Quarkonium physics in nuclear collisions @ LHC13/29
Charm production cross section
• depends on mc 1.3 GeV
• Depends on rapidity as well
• extrapolated to small energies
ccσ≈
A. Andronic et al. arXiv:0710.1851v1 [nucl-th]Source: A. Andronic et al. arXiv:0711.0974v1 [hep-ph] 127
Quarkonium physics in nuclear collisions @ LHC14/29
Charm Production Cross Section• Calculation for extrapolation
with a=4.3 and b=-1.44
b
thr
a
thrcc s
ss
sk ⎟
⎟⎠
⎞⎜⎜⎝
⎛⎟⎟⎠
⎞⎜⎜⎝
⎛−= 1σ
bk μ85.1= GeVsthr 5.4=
Quarkonium physics in nuclear collisions @ LHC15/29
Charm Balance Equation
• Balance equation
with andfrom grand-canonical densities
thcccth
occ
thoccth
occdircc Ng
NgINgINgN 2
0
1
)()(
21
+=
VnN thoc
thoc = VnN th
ccthcc =
Quarkonium physics in nuclear collisions @ LHC16/29
Canonical Suppression• Energy dependent • I1/I0 > 0.9 for LHC Energies• Dependent on centrality class
Source: A. Andronic et al. arXiv:0710.1851v1 [nucl-th] Source: A. Andronic et al. nucl-th/0611023v2
Quarkonium physics in nuclear collisions @ LHC17/29
Initially produced charm quark pairs• Strong rise with
rising Energy
• For RHIC Energy ~ 1.6 - 1.7
• Extrapolation for LHC 1 order of magnitude
Source: A. Andronic et al. arXiv:0710.1851v1 [nucl-th]
Quarkonium physics in nuclear collisions @ LHC18/29
OutlineI. Introduction
II. Melting model and kinetic model
III. Statistical Hadronization Model
IV. RHIC data and predictions for LHC
V. Experiments @ LHC
Quarkonium physics in nuclear collisions @ LHC19/29
Nuclear Modification Factor• Ratio relating yield in nucleus-nucleus
collisions to yield of N independent nucleon-nucleon collisions
with rapidity density dNJ/Ψ/dy integrated over transverse momentum pt
dydNNdydNR pp
JColl
AAJJ
AA //
/
//
Ψ
ΨΨ
⋅=
Quarkonium physics in nuclear collisions @ LHC20/29
Rapidity dependence of R
05.063.1 ±=yσ
Source: P. Braun-Munzinger, nucl-th/0701093v1
Quarkonium physics in nuclear collisions @ LHC21/29
Centrality dependence of R• Reversed
trends for RHIC data and LHC predictions
Source: P. Braun-Munzinger, nucl-th/0701093v1
Quarkonium physics in nuclear collisions @ LHC22/29
Different Production cross sections• If observed
in Experiment;striking fingerprint for deconfined quarks in QGP
Source: P. Braun-Munzinger, nucl-th/0701093v1
Quarkonium physics in nuclear collisions @ LHC23/29
Charmed Hadron Production• Open charm production in Mesons and
Baryons• Yield normalized
to yield of initial charm anticharm
• Increase in J / Ψyield
• For LHC ~ 1%
Source: A. Andronic et al. arXiv:0710.1851v1 [nucl-th]
Quarkonium physics in nuclear collisions @ LHC24/29
Mass dependence• Two models for
mass change
• Open charm vary linearly with gC
• Charmonia vary quadratic with gC
Source: A. Andronic et al. arXiv:0710.1851v1 [nucl-th]
Quarkonium physics in nuclear collisions @ LHC25/29
OutlineI. Introduction
II. Melting model and kinetic model
III. Statistical Hadronization Model
IV. RHIC data and predictions for LHC
V. Experiments @ LHC
Quarkonium physics in nuclear collisions @ LHC26/29
ALICE @ LHC• A large ion
collider experiment
• dN / dy = 8000
• Only heavy ion experiment at LHC
Quarkonium physics in nuclear collisions @ LHC27/29
ALICE @ LHC• Decay of Charmonia in hadrons, di -
muons, di – electrons …• Many particles to be
detected• Sub-detectors
TPC, TRD, ITS, etc.• charged particle
tracks
Quarkonium physics in nuclear collisions @ LHC28/29
Reference• P. Braun-Munzinger, nucl-th/0701093v1• A. Andronic, P. Braun-Munzinger, K. Redlich, J. Stachel, nucl-
th/0701079v2• A. Andronic, P. Braun-Munzinger, K. Redlich, J. Stachel,
arXiv:0710.1851v1 [nucl-th]• A. Andronic, P. Braun-Munzinger, K. Redlich, J. Stachel, Phys. Lett.
B 571 (2003) 36-44 • A. Andronic, P. Braun-Munzinger, K. Redlich, J. Stachel, nucl-
th/0209035v2• A. Andronic, P. Braun-Munzinger, K. Redlich, J. Stachel, nucl-
th/0303036v2• A. Andronic, P. Braun-Munzinger, K. Redlich, J. Stachel, nucl-
th/0611023v2• A. Andronic, P. Braun-Munzinger, K. Redlich, J. Stachel,
arXiv:0711.0974v1 [hep-ph]• T. Matsui, H. Satz, Phys. Lett. B 178 (1986) 416• H. Satz, J. Phys. G32 (2006) R25• R. Thews, M. Schroedter, J. Rafelski, hep-ph/0007323v3
Quarkonium physics in nuclear collisions @ LHC29/29
Thank you for
your attention