Post on 29-Jan-2016
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