V. GrecoV. GrecoUniversita’ di Catania, ItalyINFN-LNS

Zimanyi 75 Memorial , July 2007 – Budapest (Hungary)Zimanyi 75 Memorial , July 2007 – Budapest (Hungary)

Light and heavy quark Light and heavy quark

coalescencecoalescence

In Heavy-ion collisionsIn Heavy-ion collisions

?

Work done in collaboration withVan Hees, Ko, Levai, Rapp

First proceedings on QGP First proceedings on QGP

I looked at… I looked at…

“In the ALCOR model we assume that just before the hadronization the dense matter can be described as a mixture of dressed up, massive quarks and antiquarks. The effetive mass of the gluons at this point is much larger than that of the quarks [9], consequently the gluon fission into quark-antiquark pairs is enhanced and massive gluons disappear from the mixture.”

[9] Heinz & Levai, PRC57

Before instead Before instead

I was working on RMFTI was working on RMFT

From RHIC to LHC (new QGP phase)?! Similar RAA & v2 proof of Qq resonances in the RHIC-

QGP

presence of heavy-light Qq resonances (lQCD) Heavy quark thermalization RAA –v2 correlation of single e

link J/Y – D : one underlying HQ distribution

Ou

tlin

eHadronization mechanism & QGP structure Hadronization mechanism & QGP structure

Modification of hadronization mechanism coalescence + fragmentation (RAA&v2 Bar. – Mes.) Robustness – developments - open issues

Relevance of Coalescence in the Heavy-Quark sector Relevance of Coalescence in the Heavy-Quark sector

Light Hadrons and intermediate pLight Hadrons and intermediate pTT

Nuclear Modification Factor

ddpNdN

ddpNdpR

T

NN

coll

T

AA

TAA/

/)(

2

2

In-medium

Non-abelianenergy-loss

• Strong (Flat) suppression explained by jet quenching• Proton not suppressed ?!

• Strong (Flat) suppression explained by jet quenching• Proton not suppressed ?!

Surprises…

In the vacuum p/due to Jet fragmentation

Hadronization has been modifiedHadronization has been modified ppTT < 4-6GeV < 4-6GeV !? !?

PHENIX, PRL89(2003)

Baryon/MesonsBaryon/Mesons

Parton spectrum

H

Use medium and not vacuumMore easy to produce baryons

Greco, Ko, Levai, PRL 90 –PRC68

CoalescenceCoalescence

Baryon

Meson

Coal.

Fragmentation

Au+Au

p+p

Phase-Space Coalescence

)(δ)...,...(),()π2(

σ 111

3

3

i2 iTTnnH

n

iiiq

iiH

T

H ppppxxfpxfpd

dpgpd

dN

)(δ)...,...(),()π2(

σ 111

3

3

i2 iTTnnH

n

iiiq

iiH

T

H ppppxxfpxfpd

dpgpd

dN

fq invariant parton distribution function thermal with radial flow (=0.5r/R) quenched minijets (GLV- L/ = 3.5)fH hadron Wigner function

2

21

2

21

22

21

2 )()()(2

π9mmppxxf pxM 2

21

2

21

22

21

2 )()()(2

π9mmppxxf pxM

x =p

ET ~ 730 GeV

T ~ 170 MeV(r)~ 0.5 r/R

GeVfm-3

dS/dy ~ 4800

3D geometry with radial flow space-momentum correlation

Bulk matter consistent with hydro,

experiments, c

Bulk matter consistent with hydro,

experiments, c

2

MqqM just overlap of fq with wave function

L/

T=170 MeV

P. Levai et al., NPA698(02)

quenchedsoft hard

Baryons vs Meson

OREGON

TAMU DUKE

TAMU

v2q fitted from v2

Meson & Baryon Spectra

Greco-Ko-Levai, PRL90 (03)202302 PRC68(03) 034904R. Fries et al., PRL90(03)202303 PRC68(03)44902Hwa and Yang, PRC66(02)025205

Au+Au @200AGeV (central)ππρ

Proton suppression hidden by coalescence!

sh

ReCo dominates up to 46 GeV/c; fragmentation and energy loss takes over above.

Fries et al., PRC68

x

yz

A message from the early stageA message from the early stage

/3)(p3v)(pv

/2)(p2v)(pv

Tq2,TB2,

Tq2,TM2,

Enhancement of vEnhancement of v22Coalescence scalingCoalescence scaling

n

p

nT

2V1

baryons

mesons

Molnar and Voloshin, PRL91 (2003)

nq - not a mass effect

Most of flow is partonic

PHENIX, PRL (07)

2

22)2()(

T

T

q

T

T

M ppd

dNαp

pd

dN

3

22)3()(

T

T

q

T

T

B ppd

dNp

pd

dN

)2cos(v21φ 2

TTTT dpp

dN

ddpp

dN

x - p correlation neglectednarrow wave function

v2 develops t<5fm

Hydro & cascade

x-p correlation in Greco-Ko-Levaistill small scaling violation

Ok, but this is really too naive… (!?)Ok, but this is really too naive… (!?)1)Resonances

2)Wave function finite width

3)Gluons ALCOR, TAMU-coalescence : mass suppressed,

splitting, quark dressing Higher-Fock state, Fries-Muller-Bass, PLB618 (05)

4) Energy Conservation not large 17% in PRC68, resonances decay & v2

Ravagli-Rapp arXiv:0705.0021 for v2(KET)

5)Entropy Conservation 15% like energy – Dynamical coalescence V(r,T)

6) Relation to jet-like correlations Fries et al.,PRL94 but need of transport description

7) Space-momentum correlations affect v2 scaling

(Pratt-Pal PRC71, Molnar nucl-th/0408044 , Greco-Ko nucl-th/0505061 )

(At LHC they will still be so nice ?!)

already included

Greco-Ko-Levai, PRC68 & 70

(less important at high pT)

high pT no problem …but at lower pT

is not so drammatic

Effect of Resonances & wave function

K, , p … v2 not affected by resonances!

coal. moved towards data Greco-Ko, PRC 70 (03)

w.f. + resonance decay

K & p

*

from

On v2 it is mainly a shift in pt ->KET

v2 pions from rho decay

(Greco-Ko-Levai, PRC68&70)

Q value effect in a Boltzmann approach (Ravagli-Rapp, arXiv:0705.0021 [hep-ph] )

Greco-Ko-Levai, PRC68

40804800 HADQGP SS

SSEE // ZTT

ES log

1

But, the energy is not conserved !

15% violation, No factor 2 :- resonances- mass of the particle- degeneracies

About Energy & Entropy …

Dynamical coalescence with interaction effects

can conserve the entropy …

Entropy- Energy ConservationEntropy- Energy Conservation

1) Dynamical coalescence (no sudden f.o. - Molnar-QM05)

2)Where is confinement ?

V(r,T) (beyond sudden approx.) especially for heavy quarks -

lQCD

3) How to go from thermal to chiral masses? Although thermal quark mass does not breal chiral Symmetry and similar magnitude

of both quantities near Tc may facilitate the formation of hadrons from 2- and

3-quark clusters ( Heinz and Levai, PRC57).

4) Quasiparticle with spectral function quark mass distribution (Zimanyi-Birò-Levai, JPG31 (05) 771) good p,specra and ratio

Deeper questions… and difficult answersDeeper questions… and difficult answers

Take home messages from the light sectorTake home messages from the light sector

Hadronization from 2-3 body phase SPACE (pT< 5-6 GeV):

dense medium decrease vacuum role massive quarks close in phase space

hadrons at pt comes from quarks pt/n (change of soft scale)

Universal elliptic flow (dynamical quarks “visible”): carried by quarks enhanced by coalescence

What happens What happens

to heavy quarks?to heavy quarks?

Fries, Greco, Lacey, Sorensen - Ann. Rev. Part. Sci. (2008)

Some years ago…

V2q from , p,

v2D 5% no c interactionbut

V2 of electrons

Greco-Ko-Rapp, PLB595 (04) 202

S. Kelly,QM04

Flow mass effect

N. Armesto et al., PLB637(2006)362S. Wicks et al.,nucl-th/07010631(QM06)

lQCD resonant (bound) states persistlQCD resonant (bound) states persistfor QQ and qq -> Qq (D-like) resonant scatteringfor QQ and qq -> Qq (D-like) resonant scattering

lQCD resonant (bound) states persistlQCD resonant (bound) states persistfor QQ and qq -> Qq (D-like) resonant scatteringfor QQ and qq -> Qq (D-like) resonant scattering

RRAA AA , v, v22 of single e -pQCD of single e -pQCD

Radiative energy loss not sufficient

sQGP: non perturbative effect q

q

A() 2()Asakawa

J/

J/ (p 0) disappearsbetween 1.62Tc and 1.70Tc

“Light”-Quark Resonances

1.4Tc

[Asakawa+ Hatsuda ’03]

Spectral function in lQCDSpectral function in lQCD

Similar from Potential model for J/

Mannarelli, Rapp - PRC72 (Bruckner-like)

Alberico, Beraudo, De Pace - PRD 72 & 75

Petrecsky,Mocsy,Wong….

t eq down to 5 fm/c at RHIC ! t eq down to 5 fm/c at RHIC !

Open-Charm Resonances in QGP

• effective model with pseudo/scalar + axial/vector “D-like” mesons [chiral + HQ symmetry]

• cross section ISOTROPICISOTROPIC • more microscopic from lQCD potential+many-body [Mannarelli et al.,in preparation] Ok, but can it describe ROk, but can it describe RAAAA and v and v22??Ok, but can it describe ROk, but can it describe RAAAA and v and v22??

with dimensional regularizationor form factors

55 ,,,1

h.c.2

)v1(

cqG DDDcq L

The modelThe model

Hard productionHard production

PYTHIA (PDF’s + pQCD )

HQ scattering in QGPHQ scattering in QGPLangevin simulation

in Hydro bulk

HadronizationHadronization

Coalescence + Fragmentation

Semileptonic decaySemileptonic decay

RAA & v2 of “non-photonic” e

sQGP

c,b quarks

K

e

e

2

,2

,, )(

p

fD

p

pf

t

f bcbcbc

BDbcbcMqbcBDBD DfffC

Pd

Nd,,,,,3

,3

c,b

D,B

Charm reaching thermalization?!Charm reaching thermalization?!

Therm+Flow

Pythia

Reson.

pQCD

frag)()(|)(|)2(

23

33

ccqqDDD pfpfqqd

pdg

pd

dNE

Single-ElectronSingle-Electron vv22 andand RRAAAA at RHICat RHIC

fq from , KGreco,Ko,Levai - PRL90

coalescence+ fragment.

• resonant scattering more effective for RAA

– v2 correlation

• coalescence increases both RAA and v2

(anti-correlation)

• resonant scattering more effective for RAA

– v2 correlation

• coalescence increases both RAA and v2

(anti-correlation)

Hees, Greco, Rapp - PRC73

Uncertainty:-better estimate of B/C contributionImprovements:- include radiative E-loss - resonances from lQCD – potential model- no-sudden coalescence (full transport)

Uncertainty:-better estimate of B/C contributionImprovements:- include radiative E-loss - resonances from lQCD – potential model- no-sudden coalescence (full transport)

Regeneration is revealed in : - pt spectra - elliptic flow

Quarkonium Heavy-Quark

Till now we have looked only at J/ yield, but thanks to such a strong collective dynamics …

Greco, Ko, Rapp PLB595(2004)

Jcoal.

No feed-downNo direct contr.

pT- Quarkoniafrom regeneration

consistent with Open!?

Suppression only

v2Y from v2D :measure of

Ncoal/NINI

Coalecence only

Tdiss(pT) decrease – AdS Liu et al. hep-ph/0607062

From RHIC to LHC?From RHIC to LHC?

For min. bias.For min. bias.

Hydro bulk dN/dy=1100

Tinit= 3 Tc

Radial flow max=0.68

V2q light quark =7.5 % (hydro or numerology)

v2q(pT) from a cascade [VG, Colonna, Ferini, Di Toro]

Resonances off T>2TResonances off T>2Tcc

From RHIC to LHC - RFrom RHIC to LHC - RAAAA

RHIC LHC

Suppression: RAA similar at RHIC and LHC!

Harder initial spectra at LHCResonance ineffective (“melted” T>2Tc) at early stage!

bottom

charm charm

bottom

From RHIC to LHC – vFrom RHIC to LHC – v2 electrons2 electrons

v2 similar at RHIC and LHC!

Resonance effective when anisotropy is reduced Strong drag with the bulk flow at later stage! v2 slightly higher at low pt

RHIC LHC

from D only

ALICE

Warning! Radiative energy loss to be included!

SummarySummary Coalescence from a bulk consistent with exp. and hydro

Yields, ratios, D-fluctuations RAA, Rcp,V2/nq vs pT

Beyond naïve coalescence -> better data description

3D, resonances, wave function, Fock states, energy conservation

RAA - v2e anti-correlation for HQ entails: - presence of Q-q resonances (lQCD)

Similar RAA & v2 at RHIC- LHC: - if from RHIC to LHC a new QGP phase is created !

Consistency of D and J/ with one underlying

distribution ?! better insight into coalescence at low pT– V(r,T)

2-3 body phase-spacebehind hadronization

Relevance of Coalescence in the Heavy-Quark sector Relevance of Coalescence in the Heavy-Quark sector

Back up slidesBack up slides

Baryon contamination due to coalescence …Baryon contamination due to coalescence …

• Contamination of Lc in single e : enhance v2e: v2c > v2D

• enahencement modest + BRe 4.5%

but if one can verify those prediction …

Heavy-Flavor and jet quenching- Workshop, Padova 29-9-2005Heavy-Flavor and jet quenching- Workshop, Padova 29-9-2005

P. Soresen, nucl-ex/0701048G. Martinez-Garcia et al., hep-ph/0702035

Apparent reduction if c/D ~1consistent with RHIC data (pt~2-4 GeV)

coal.

coal.+ fragm. = 0.75 GeV

Thermalization w “D”-Mesons

pQCD

“D”QGP- RHIC

Isotropic angular distribution sres essential for thermalization

2

2)(

p

fD

p

pf

t

f

Transport approximated Fokker-Plank equation

Background not affected by heavy quarks

What is the RWhat is the RAAAA and v and v22 ? ?

Cross section Equilibration time

Heavy-Flavor Baseline Spectra at RHICHeavy-Flavor Baseline Spectra at RHIC Single-Electron Decays D-Mesons

• bottom crossing at 5GeV !? • strategy: fix charm with D-mesons, adjust bottom in e±-spectra

Improve treatment of fluctuations (not Gaussian)Include hadronization: coal+ fragmentation

I. Vitev, A. Adil, H. van Hees, hep-ph/0701188

Inclusion of radiative E-lossInclusion of radiative E-loss

w/o gluon radiation

RRAA AA & v& v2 2 for D/B mesons at LHCfor D/B mesons at LHC

D and B via coalescence+ fragmentation!

coalescence leads to increase both RAA and v2

resonant scattering factor 3 in v2

What happens at lower energy –RHIC @62?What happens at lower energy –RHIC @62?

p+/ increase by 20%p/ decrease slight decreaseGreco ,Ko, Vitev - PRC71

Without changing any coalescence parameter!

Balance between fragmentation (w quenching) and coalescence

Uncertainties: amount of quenching,bulk properties (ET, b,..), p fragmentationfunction

What happens at higher energy - LHC?What happens at higher energy - LHC?

Fries, Muller, EPJ C34:S279 (2004).

Similar trend for MICOR + pQCD(quenched)P. Levai - ALICE Week- February 2007

Uncertainties:- radial flow (=0.65-075)- jet quenching

What about the v2 ?

we will see the scaling?r-p correlation will be so nice at LHC?

Charm reaching thermalization?Charm reaching thermalization?Shadowing not included yet!Spectra same parameter of PPR-ALICE

Therm+Flow

Pythia

LHC spectra considerably harder ! At Tc charm nearly thermalizedAt Tc charm nearly thermalized

Resonances switched-off above 2 TResonances switched-off above 2 Tcc