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