experimental overview

Federico Antinori - Levoča - 29 jún 2007Federico Antinori - Levoča - 29 jún 2007 11

experimental overviewexperimental overview

Federico AntinoriFederico Antinori(INFN Padova & CERN)(INFN Padova & CERN)


DisclaimerDisclaimer

This selection is biassed and incomplete:This selection is biassed and incomplete: too much material, not enough timetoo much material, not enough time I concentrated on I concentrated on flavourflavour results results and my personal selection at thatand my personal selection at that

in particular: in preparing this talk in particular: in preparing this talk I have not tried to be ecumenicalI have not tried to be ecumenical I have tried to share with you what I’ll take home from this I have tried to share with you what I’ll take home from this

beautiful conferencebeautiful conference


ContentsContents

StrangenessStrangeness

QuarkoniaQuarkonia

Heavy FlavourHeavy Flavour

ConclusionsConclusions


StrangenessStrangeness

55

MotiváciaMotivácia s particle production suppressed (wrt production of s particle production suppressed (wrt production of

light flavour) in elementary collisionslight flavour) in elementary collisions

large system should easelarge system should ease ifif strangeness can be conserved over a large volume strangeness can be conserved over a large volume i.e.: correlation volume large! (e.g.: quarks freed in i.e.: correlation volume large! (e.g.: quarks freed in

QGP)QGP) if AA were simple superposition of pp if AA were simple superposition of pp no enhancement no enhancement

if sistem deconfined and particles built if sistem deconfined and particles built by recombination, expect larger by recombination, expect larger enhancement for multi-strangeenhancement for multi-strange enhancement increasing with s contentenhancement increasing with s content

enhancementenhancementremoval of suppressionremoval of suppression

s

u

s

d

u du

u

u

u

uu

u

u

uu

u

uu

u dd

d

d

d

d

d

d

d dd

dd

ds

s

s s

s

s

s

s

s

s

s ss

sd d

dd

d

dd

uu

u

u

uuu

u

d

K+

u+

+

-

p

-

[[Rafelski: Phys. Rep. 88 (1982) 331]Rafelski: Phys. Rep. 88 (1982) 331][Rafelski-Müller: P. R. Lett. 48 (1982) 1066[Rafelski-Müller: P. R. Lett. 48 (1982) 1066]][Koch, Müller & Rafelski: Phys. Rep. 142 (1986) [Koch, Müller & Rafelski: Phys. Rep. 142 (1986) 167]167]


centrality dependence also important to constrain models ! e.g.: “canonical suppression model” fast saturation with centrality

[Hamieh et al.: Phys. Lett. B486 (2000) 61]

Hyperon enhancementsHyperon enhancements top SPStop SPS

NA57

NA49

Giuseppe Bruno

Christoph Blume


energy dependence also constrains modelsenergy dependence also constrains models e.g. much weaker than predicted by canonical suppression e.g. much weaker than predicted by canonical suppression

model:model:

40 GeV

160 GeV

1

10

Redlich et al., JPG28 (2002) 2095

Giuseppe Bruno (NA57)


Hyperon enhancements @ RHICHyperon enhancements @ RHIC

still strong, a bit lower than @ SPSstill strong, a bit lower than @ SPS

open: NA57 @ SPSopen: NA57 @ SPS closed: STAR @ RHICclosed: STAR @ RHIC

Lee Barnby (STAR)


Now also Cu-CuNow also Cu-Cu

similar to Au-Ausimilar to Au-Au

Jun Takahashi (STAR)

open: Au-Au (STAR)open: Au-Au (STAR) closed: Cu-Cu (STAR)closed: Cu-Cu (STAR)


and also for and also for ΦΦ

role of canonical suppression?role of canonical suppression?

Nu Xu (STAR)


RRCPCP @ SPS @ SPS

Larger than @ RHICLarger than @ RHIC

NA49

PHENIX

NA49 preliminary NA49 preliminary

NA49 preliminary -0.3 < y < 0.7

Christoph Blume (NA49)


RRCPCP @ SPS @ SPS

no evidence for high pno evidence for high pTT suppression (Rsuppression (RCPCP < 1) < 1)

but similar relative but similar relative KK00

SS// pattern as at RHIC pattern as at RHIC



Relative Relative ΛΛ,K,K00SS R Rcpcp pattern ~ independent of √s, coll. pattern ~ independent of √s, coll.

systemsystem



KK00SS from NA45 from NA45

New approach:New approach: does not use separation of Kdoes not use separation of K00

SS vertex from primaryvertex from primary

use all (+,-) combinationsuse all (+,-) combinations S/B ~ 10S/B ~ 10-3-3

subtract mixed-events bckg and subtract mixed-events bckg and

sensitivity at low psensitivity at low pTT

Sylwester Radomski (NA45)


Sylwester Radomski (NA45)


NA57-NA49-NA45 kaon NA57-NA49-NA45 kaon comparisoncomparison

not too bad…not too bad…

NA57 0-11%

NA49 0-10%

NA49 Nucl. Phys. A715 (2003) 453c, QM2002

NA45 0-7%scaled to 0-10%

NA49 0-5%scaled to 0-10%

K0s

½(K++K-)

NA49 Phys. Rev. C 66, 054902 (2002)NA57 Jour. Phys. G 31 (2005) 1345-1357NA45 S. Radomski Ph.D. thesis

5.0

5.0dy

dy

dNY



Recombination triumphantRecombination triumphant

multi-strange enhancementsmulti-strange enhancements kinetic evidence from nkinetic evidence from nqq scaling of v scaling of v22, R, RCPCP

(+ KE(+ KET T at low momentum)at low momentum)Phys. Rev Lett. 98, 162301 (2007)

Hugo Pereira (PHENIX)


a flea in the ontiment?a flea in the ontiment?

shower (S) + thermal (T) recombinationshower (S) + thermal (T) recombination ΩΩ-- mostly from TTT (shower s suppressed) mostly from TTT (shower s suppressed)

[RC Hwa & CB Yang nucl-th/0602024]

no no ΩΩ-- in jets? in jets? but Ωbut Ω-- shows same side peak… shows same side peak…

Betty Abelev (STAR)


……Fyre Burn & Cauldron Bubble…Fyre Burn & Cauldron Bubble…

e.g. STAR, using e.g. STAR, using ThermusThermus

Ye Thermal Fyttes Are Doing Well! Ye Thermal Fyttes Are Doing Well! (as usual…)(as usual…)


200 GeV

62.4 GeV


remarkable regularity in freeze-out systematicsremarkable regularity in freeze-out systematics

Jean Cleymans


Thermal parameters vs y?Thermal parameters vs y?

chemistry depends on ychemistry depends on y e.g.: baryon densitye.g.: baryon density

“net”

pro

ton

AGS

SPS

RHIC 62

RHIC 200

LHC 5500

dN

/dy

(BRAHMS preliminary)

Michael Murray (BRAHMS)


Thermal parameters vs y!Thermal parameters vs y!

how to interpret T, µhow to interpret T, µBB from “4 from “4ππ”fits?”fits?

Jean Cleymans


(+ the step, the jump, the kink, the stomp, the bump, the whoopee…)(+ the step, the jump, the kink, the stomp, the bump, the whoopee…)

new expeditions to the region are being organizednew expeditions to the region are being organized

Low SPS energy anomalies?Low SPS energy anomalies?

[Marek Gazdzicki (NA49) QM04]Jan Rafelski

a.k.a. “the horn”a.k.a. “the horn”


Lower energy still…Lower energy still…

again, thermal fit very good…again, thermal fit very good… Al+Al @ 1.9 A GeV (FOPI)Al+Al @ 1.9 A GeV (FOPI)

MeV780μ

MeV70T4080b

64

Al+Al

THERM. MOD.: .A. Andronic et al., NPA 772 (2006) 167

Xavier Lopez (FOPI)

chemical T < kinetic Tchemical T < kinetic T

exception to systematics?exception to systematics?


ResonancesResonances

time

signal lost

signal measured late decay

signal measured

signal measuredearly decay

che

mic

al fr

eeze

-o

ut

p

pp

kin

etic

fre

eze

-out

re-scattering

regeneration

e+

e-leptonic decay

hadronic decay

Christina Markert (STAR)


Resonance suppressionResonance suppression

can we extract information on system timescales?can we extract information on system timescales?

Life-time [fm/c] :K(892) = 4.0 =(1520) = 13 (1020) = 45



K* vK* v22

Agrees better with n=2 Agrees better with n=2 expect n=4 from Kexpect n=4 from Kππ coalescence coalescence



Mass shifts?Mass shifts?

e.g.: STAR K*e.g.: STAR K* ~ 10 MeV shift observed at low p~ 10 MeV shift observed at low pTT

could we be onto something?could we be onto something?

PDG K*0

PDG K*±

STAR Preliminary

MC

Patricia Fachini

same effect also in pp…same effect also in pp…


Caveat…Caveat… 10 MeV shift comparable with typical size of instrumental 10 MeV shift comparable with typical size of instrumental

effects… e.g.:effects… e.g.:

D0+D0

NA45 KNA45 K00: a few MeV: a few MeV

STAR DSTAR D00 from e – D from e – D00 analysis: analysis:

~ 25 MeV~ 25 MeV

NA57 KNA57 K00: a few MeV: a few MeV


The SPS The SPS ΦΦ puzzle puzzle (NA49 vs NA50)(NA49 vs NA50)

News from NA60: better agreement with NA49, at least at low pNews from NA60: better agreement with NA49, at least at low pTT

NA60 In-In (pT < 1.6 GeV/c)NA49 Pb-PbNA50 Pb-Pb

NA60 In-In (pT > 1.1 GeV/c)NA49 Pb-PbNA50 Pb-Pb

Absolute yield in progressAbsolute yield in progress

Michele Floris (NA60)

Similar conclusion from NA45Similar conclusion from NA45

[NA45 - PRL 96 (2006) 152301]


Quarkonia (& dileptons)Quarkonia (& dileptons)


J/J/ψψ suppression suppression present status:present status:

SPS RHIC LHC

very similar suppression at very similar suppression at RHIC and SPS...RHIC and SPS... only only ’and ’and cc melt? melt? J/J/ melting compensated by cc melting compensated by cc

recombination?recombination?

at LHC we should at LHC we should finally be able to finally be able to tell...tell...

larger larger J/ J/ finally melts? finally melts?

more cc more cc reco dominates? reco dominates?

F.Karsch et al.: PLB637 75 (2006)


J/J/: R: RAAAA at large rapidity at large rapidity

Larger suppression at Larger suppression at larger rapiditylarger rapidity

What controls suppression?What controls suppression? energy density?energy density? ……??

NA50 at SPS (0<y<1)PHENIX at RHIC (|y|<0.35)PHENIX at RHIC (1.2<|y|<2.2)

Hugo Pereira (PHENIX)


ΥΥ in STARin STAR

• unlike-sign pairs— like-sign pairs

Lee Barnby (STAR)


Intermediate mass excess (NA60)Intermediate mass excess (NA60)

Fit weighted impact parameter distributionFit weighted impact parameter distribution prompt from J/prompt from J/ψψ dimuons, charm from PYTHIA dimuons, charm from PYTHIA requires > 2 x expected D-Y to fit datarequires > 2 x expected D-Y to fit data

6500 A, 2match < 3

sensitivity to assumption on cc psensitivity to assumption on cc pTT, , ΔφΔφ extracted value of cc cross section ~ 2 – 3 larger than extrap.extracted value of cc cross section ~ 2 – 3 larger than extrap.

but compatible with extrapolation from NA50 p-Abut compatible with extrapolation from NA50 p-A

NA60

H.Woehri and C.Lourenco, Phys.Rep. 433 (2006) 127-180



Intermediate mass excess (NA60)Intermediate mass excess (NA60)

Centrality and pT distribution of excessCentrality and pT distribution of excess



PHENIX di-leptonsPHENIX di-leptons Low mass enhancement!Low mass enhancement!

+ intermediate mass suppression?+ intermediate mass suppression?

p+p Au+Au minimum bias

Watch this space!Watch this space!Christian Klein-Bösing (PHENIX)


Heavy FlavourHeavy Flavour


MotiváciaMotivácia

study medium with probes of known colour charge study medium with probes of known colour charge and massand mass e.g.: energy loss by gluon radiation expected to be:e.g.: energy loss by gluon radiation expected to be: parton-specific: stronger for gluons than quarks (colour parton-specific: stronger for gluons than quarks (colour

charge)charge) flavour-specific: stronger for lighter than for heavier quarks flavour-specific: stronger for lighter than for heavier quarks

(dead-cone effect)(dead-cone effect) study effect of medium on fragmentation (no extra study effect of medium on fragmentation (no extra

production of c, b at hadronization)production of c, b at hadronization) independent string fragmentation vs recombinationindependent string fragmentation vs recombination e.g.: De.g.: D++

ss/D/D++

+ measurement important for quarkonium physics+ measurement important for quarkonium physics open QQ production natural normalization for quarkonium open QQ production natural normalization for quarkonium

studiesstudies B meson decays non negligible source of non-prompt J/B meson decays non negligible source of non-prompt J/


Experimental techniques @ Experimental techniques @ RHICRHIC


Non-photonic electronsNon-photonic electrons Identified electron spectraIdentified electron spectra

STAR: dE/dx in TPC + TOF at low pSTAR: dE/dx in TPC + TOF at low pTT, EMC at high p, EMC at high pTT

PHENIX: combined RICH and E/p (with E from EM cal)PHENIX: combined RICH and E/p (with E from EM cal)

Rejection of non-heavy-flavour electronsRejection of non-heavy-flavour electrons Main source of electrons: “photonic”Main source of electrons: “photonic”

ee++ee-- conversions conversions Dalitz decays Dalitz decays 00 e e++ee-- Dalitz decays Dalitz decays e e++ee--

STAR:STAR: rejected by full invariant mass analysis of erejected by full invariant mass analysis of e++ee-- combinations combinations

PHENIX:PHENIX: estimated by simulation and subtracted (“cocktail method”)estimated by simulation and subtracted (“cocktail method”) measured by “converter method” and subtractedmeasured by “converter method” and subtracted

Other sources of non-charm electrons:Other sources of non-charm electrons: ,,,,, K decays, K decays

estimated by sim. and subtracted (in both STAR and PHENIX)estimated by sim. and subtracted (in both STAR and PHENIX)

(“internal conversions”)(“internal conversions”)


Reconstructed decays (STAR)Reconstructed decays (STAR)

DD00 K K tracks from TPCtracks from TPC K, K, identification from dE/dx identification from dE/dx no separation of D decay vertexno separation of D decay vertex large combinatiorial background large combinatiorial background

evaluated by event mixing and evaluated by event mixing and subtractedsubtracted

that still leaves substantial that still leaves substantial background, subtracted with linear background, subtracted with linear fitfit

Andre Mischke (STAR)


Low pLow pTT muons (STAR) muons (STAR)

in TPC (dE/dx)in TPC (dE/dx)

22 in TOFin TOF

3.3. fit to impact fit to impact parameter parameter distributiondistribution charm charm should ~ should ~

point to primary...point to primary...

[C Zhang (STAR) QM06]


Experimental statusExperimental status

4545

PHENIX ppPHENIX pp

Excess wrt FONLL:Excess wrt FONLL:

Similar situation also in CDF:Similar situation also in CDF:

[A. Adare et al. (PHENIX) Phys.Rev.Lett. 97 (2006) 252002]

Ratio: 1.72 0.02 (stat) 0.19 (sys)(0.3 < pT < 9.0 GeV/c)

D0

[D. Acosta et al. (CDF) PRL 91 (2003) 241804]

DongJo Kim (PHENIX)


STAR v PHENIX ppSTAR v PHENIX pp

~ a factor 2 discrepancy~ a factor 2 discrepancy

hep-ex/0609010

[J. Lajoie (PHENIX) QM06]


STAR dAu, AuAuSTAR dAu, AuAu

Internal consistencyInternal consistency

[M. Calderon (STAR) QM06]

Lee Barnby (STAR)


STAR v PHENIX dAu, AuAuSTAR v PHENIX dAu, AuAu Discrepancy pretty “stable” v collision system, channel, pDiscrepancy pretty “stable” v collision system, channel, pTT

0,0 0,5 1,0 1,5 2,0 2,5 3,010-5

10-4

10-3

10-2

10-1

100

1/(2N

evp T

)d2 N

/dp T

d y [(G

eV/c

)-2]

pT [GeV/c]

STAR Combined fit MB , electrons and D-mesons

Phenix MB Au+Au data

looks like something very basic...looks like something very basic...

[A. Suaide QM06]


a curiosity…a curiosity…

STAR yield larger than STAR yield larger than PHENIX yield for PHENIX yield for ΦΦ

STAR

PHENIX

STAR + PHENIX

Patricia Fachini

J. Rafelski et al.,Phys.Rev. C72 (2005) 024905


STAR v PHENIX dAu, AuAuSTAR v PHENIX dAu, AuAu Discrepancy pretty “stable” v system, pDiscrepancy pretty “stable” v system, pTT

0,0 0,5 1,0 1,5 2,0 2,5 3,010-5

10-4

10-3

10-2

10-1

100

1/(2N

evp T

)d2 N

/dp T

d y [(G

eV/c

)-2]

pT [GeV/c]

STAR Combined fit MB , electrons and D-mesons

Phenix MB Au+Au data

looks like something very basic...looks like something very basic... of course then Rof course then RAAAA not too different... not too different...

[A. Suaide QM06]


STAR v PHENIX: RSTAR v PHENIX: RAAAA

RRAAAA of non-photonic electrons of non-photonic electrons

[A. Suaide QM06]

similar picture from STAR and PHENIXsimilar picture from STAR and PHENIX


InterpretationsInterpretations


Theoretically...Theoretically...

Energy loss for heavy flavours is expected to be reduced:Energy loss for heavy flavours is expected to be reduced:i)i) Casimir factorCasimir factor

light hadrons originate from a mixture of gluon and quark jets, light hadrons originate from a mixture of gluon and quark jets, heavy flavoured hadrons originate from quark jets heavy flavoured hadrons originate from quark jets

CCRR is 4/3 for quarks, 3 for gluons is 4/3 for quarks, 3 for gluons

ii)ii) dead-cone effectdead-cone effect gluon radiation expected to be suppressed for gluon radiation expected to be suppressed for < M < MQQ/E/EQQ

[Dokshitzer & Karzeev,[Dokshitzer & Karzeev, Phys. Lett. Phys. Lett. B519B519 (2001) 199] (2001) 199][Armesto et al., Phys. Rev. D69 (2004) 114003][Armesto et al., Phys. Rev. D69 (2004) 114003]

2 ˆ LqCE Rs

Casimir coupling factor

transport coefficient of the medium

average energy lossdistance travelled in the medium

R.Baier et al., Nucl. Phys. B483 (1997) 291 (“BDMPS”)


Experimentally...Experimentally...

non ph. el. ~ as non ph. el. ~ as suppressed as light suppressed as light hadronshadrons

use of high density use of high density (qhat), introduction of (qhat), introduction of elastic (in addition to elastic (in addition to radiative) energy loss... radiative) energy loss... not enoughnot enough

high qhat and no beauty high qhat and no beauty electrons does betterelectrons does better

[B.I. Abelev et al (STAR): nucl-ex/0607012]


How much beauty?How much beauty? high phigh pTT region expected region expected

to be beauty-dominated to be beauty-dominated but how “high”?but how “high”?

[M. Cacciari et al.: PRL 95 (2005) 122001]

not easy to disentangle c/b not easy to disentangle c/b contributions to RHIC non ph. el. contributions to RHIC non ph. el. samples (no heavy flavour vertex samples (no heavy flavour vertex detectors in RHIC experiments)detectors in RHIC experiments)

[A. Suaide QM06]


e-h correlations in STARe-h correlations in STAR idea: Midea: MBB > M > MDD larger transverse kick for B electrons larger transverse kick for B electrons less pronounced correlation in B wrt D decaysless pronounced correlation in B wrt D decays

e-h from Be-h from DFit

from simulation of PYTHIA events

[X. Y. Lin: hep-ph/0602067][X. Y. Lin: QM06]

nice idea, of course relies heavily onnice idea, of course relies heavily on understanding of purity of “non ph. el.” understanding of purity of “non ph. el.” accuracy of simulationaccuracy of simulation

taken at face value: FONLL ratio ~ OKtaken at face value: FONLL ratio ~ OK

but then B also enhanced?but then B also enhanced?

Xiao Yan Lin (STAR)


New approachNew approach electron-Delectron-D00 correlations in STAR (in pp) correlations in STAR (in pp)

Andre Mischke (STAR)


By the way: the factor 9/4? By the way: the factor 9/4?

energy loss should be energy loss should be proportional to: proportional to: CCRR = 4/3 for q, = 3 for g = 4/3 for q, = 3 for g

at RHIC, at 6-8 GeV pat RHIC, at 6-8 GeV pTT: : x ~ 10 x ~ 10-1-1

large quark contribution large quark contribution also for light flavours?also for light flavours?

at LHC, at same pat LHC, at same pTT: : x ~ a few 10 x ~ a few 10-4-4

quark contribution quark contribution negligiblenegligible


E loss being understood?E loss being understood?

DongJo Kim (PHENIX)


another sobering caveat…another sobering caveat…

Relative abundances in charm sector also important:Relative abundances in charm sector also important:

c/D

(e c)/(e D)

DD00 DD DDss++ cc

++

BR (XBR (Xe) e) in %in %

17.2 17.2 1.91.9

66..71 71 0.290.29

8 +6-58 +6-5 4.5 4.5 1.7 1.7

Sebastien Gadrat

(see also P Sorensen & X Dong, PRC 74 (2006) 024902)

and what about Dand what about Dss?? s enhancement!s enhancement!

e.g.: e.g.: ΛΛcc/D may change /D may change from pp to AAfrom pp to AA


Vertex Detectors!Vertex Detectors!

need less indirect measurementneed less indirect measurement

full reconstruction of charm decays!full reconstruction of charm decays! get rid of b/c ambiguitiesget rid of b/c ambiguities study relative abundances in charm sectorstudy relative abundances in charm sector

Silicon Pixels in ALICE (+ ATLAS, CMS)Silicon Pixels in ALICE (+ ATLAS, CMS)

Silicon Vertex upgrades in STAR, PHENIXSilicon Vertex upgrades in STAR, PHENIX


tDpp

tDAA

collt

DAA dpdN

dpdN

NpR

/

/1)(

tepp

teAA

collt

eAA dpdN

dpdN

NpR

/

/1)(

Expected ALICE performance on D, B Expected ALICE performance on D, B RRAAAA

mb = 4.8 GeV

D0 K B e + X

1 year at nominal luminosity(107 central Pb-Pb events, 109 pp events)

mass dependencecolour charge dependence

)()()( D from eB from e/ tAAtAAtDB pRpRpR )()()(/ t

hAAt

DAAthD pRpRpR

Andrea Dainese (ALICE)


ConclusionsConclusions

Flavour in Quark Matter is going strong!Flavour in Quark Matter is going strong!

Extension to hard sector tantalizingly promisingExtension to hard sector tantalizingly promising

Heavy flavour: we need more experimental Heavy flavour: we need more experimental information!information!

two quantum jumps ahead:two quantum jumps ahead: vertex detectors (ALICE, ATLAS, CBM, CMS, PHENIX, STAR)vertex detectors (ALICE, ATLAS, CBM, CMS, PHENIX, STAR) LHCLHC

very high rates (expect ~ 100 cc, ~ 5 bb per central Pb-Pb!)very high rates (expect ~ 100 cc, ~ 5 bb per central Pb-Pb!) truly hard probestruly hard probes + low x !+ low x !


A big A big

ĎakujemĎakujem to the Organizers to the Organizers for an excellent for an excellent

SQM 2007 ConferenceSQM 2007 Conference(from every point of view)(from every point of view)

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