rcnp qgp workshop 2004/11/04shinichi esumi, univ. of tsukuba1 high-energy heavy-ion collisions...

RCNP QGP workshop 2004/11/04 ShinIchi Esumi, Univ. of Tsukuba 1

High-energy heavy-ion collisions viewed with v2, singles and HBT measurements.

ShinIchi Esumi, Univ. of Tsukuba

v2 – initial geometry and partonic flow and jetssingles(ratio and spectra) – chemical/thermal f.o.HBT – space-time information


initial state

pre-equilibrium

QGP andHydro. expansion

Hadronization

Elastic scatteringand kinetic freeze-outHadronic interaction

and chemical freeze-out

Time

? ?

TC=170 MeVC=0.5 GeV/fm3

Decreasing energy density

S. Bass

高エネルギー重イオン衝突における衝突領域の時間発展

v2

particle ratio

particle spectra

HBT


Au+Au collisions in sqrt(sNN)=200GeV with

Relativistic Heavy Ion Collider (RHIC) at BNL

PHENIX

mid-rapidity hadron/electron/ photon spectrometer

Forward-rapidity muon spectrometer


BBC/ZDC : centralityDch/PC1,2,3 : trackingTof : hadron PIDRich : electron PIDEmcal : electron/photon PID


Beam-beam counter(BBC) ||=3~464pmts in each BBC charged particles

two central arms (CNT) ||<0.35Dch,PCs,TOF,EMCALtracking, momentum, PID

collision point

beam line

dNch

/d

-6 -3 0 3 6

Zero Degree CalorimeterShower-Max DetectorSpectator neutron energyBeam position

BBC

CNT

ZDC/SMD

MuonMuon arm +Silicon multiplicity(MVD) endcap

MVD

Reaction plane detectors in PHENIX

South North


Target

Projectile

b:impact parameter

React

ion

plan

e Reaction plane

initial geometryfinal momentum anisotropy

parton

parton

hadrons

A+A

p+p

Experimentally, the R.P. is defined by the event anisotropy by itself.


collisionvertex

BBCMVD


LED flasher

Scintillator strips

WLS fibers

16ch. PMT “M16”

Shower Maximum Detector (SMD)

horizontal-strips

vertical-strips

(X-CX)/X

(Y-C

Y)/ Y

(X-CX)/X

SMD1 SMD2

SMD1 (South) SMD2 (North)

beam spot distribution

X (cm) X (cm)

Y (

cm)

SMD


SMD1vsSMD2BBC1vsBBC2 SMDvs BBC

BBC1vs

BBC2

back-to-back back-to-back spectator neutrons vss from participants are flowing opposite.

MVD1vs

MVD2 BBCvs

MVD


particleR.P. (rad)

beam linereaction plane

neutron spectator

charged particles(pions) at mid

beam


PHOBOS : nucl-ex/0406021

PHENIX Preliminary

indication of v2 saturation at RHIC energy


Thermal model with blast-wave

hydro is really good to be truth!!What will happen with resonances?

Resonance effects are important in single spectra, but not too much in v2, because of pT shift of heavy particles having smaller v2 and linear pT dependence of v2.


Phys

.Let

t. B59

7 (2

004)

328

-332

, X. D

ong

et.al

.

Phys

.Rev

. C70

(200

4) 0

2490

1, V

. Gre

co et

.al

Pion deviation is explained by resonance decays

pT shift is the dominant effect compared to the smearing given by the opening angle.


hydro + jet

quark coalescence

recombination + fragmentation

Data prefer “quark coalescence / recombination” based picture rather than “hydro + jet” picture at intermediate pT.

QGP


minimum bias Au+Au at sNN = 200 GeV

PHENIX preliminary

some remainingmass ordering

PHENIX preliminary

quark + hadron flow

Tfo

初期離脱

SPS

Similar effect from the time-difference is seen in v2

Almost NOmass ordering


hydro + jet

Jets dominate the high pT part of spectra.


PHENIX STAR

And they (jets) are suppressed.


0.906 < < 1.042

dN/dy = A (Ncoll)

charmed e,e pT distribution

PHENIX Preliminary

PHENIX Preliminary

Charm quarks are not suppressed w.r.t. binary scaling compared to the light quarks, but it could be enhanced and suppressed (looked like binary scaled). The v2 of charm would give a hint for the answer to the question.


inclusive ee v2

charmed ee v2

If charm quarks also flow, charm quarks are thermalized and / or suppressed similarly to the light quarks.

STAR SQM04


Inclusive Single

PHENIX Preliminary

Run2 AuAu 200 GeV

1 + ( pQCD direct x Ncoll) / ( phenix pp backgrd x Ncoll)

[w/ the real, suppressed background]

PHENIX Preliminary

AuAu 200 GeV Central 0-10%

1 + ( pQCD direct x Ncoll) / phenix backgrd Vogelsang NLO

pT (GeV/c)

Direct photons are enhanced w.r.t. production, but it’s just because is suppressed, and the direct photons are in fact binary scaled.


vertical bar : stat. errorcurves, gray box : sys. error

phenix preliminary

Note : Inclusive photon = including all of the decay effect from hadrons

phenix preliminary phenix preliminary

pT [GeV/c]

, 200 GeV Au+Au , 200 GeV Au+Au , 200 GeV Au+Au

Direct photons should not have any flow by definition, but …Alternatively ratio can be measured by assuming v2

=0.

The difference here and the ratio will give us a measure of direct v2.


1<p T

(ass

ocia

te) <

1.5G

eV2.

5<p T

(ass

ocia

te) <

3GeV

hadron-hadron correlation (full pT reference)

(rad)

pure harmonic function fit

1.1

1.0

0.91.1

1.0

0.9

harmonic +near-side Gaussfunction fit

0. 0. 0.

harmonic +near-side +Far-side Gaussfunction fit

harmonic function fixed to themeasured v2

Au+Au 200GeV PHENIX preliminary

Another way to get the v2 : (v2)2 is given by the pair correlation

Ways to reduce the jet correlation with additional Gauss terms

A{1+2 (v2)2 cos(2)} + Gauss term


PHENIX Preliminary

Reac. plane v2 does have less non-flow because of the gap.Non-flow are removed in 2 part. corr. 2nd cumulant …


phenix preliminary

}nucl-ex/0305013

Au+Au 200 GeV Au+Au 200 GeV

v2 reduction of charged particles in the previous page could be enlarged by the baryon/meson ratio.


STAR2

par

ticl

e co

rrel

atio

n(v

2 +

no

n-f

low

)The difference here is given by the real flow (v2).


STAR : nucl-ex/0409033 non-flow reduced

v2{2}

v2{RP}

v2{4}

STAR Preliminary

charged particle v2

v2{2}

v2{RP}

Jet suppression ends somewhere …



semi-old STAR data

old STAR data

no jet-quenching


leading parton

hadrons

Q: Are jets source of v2?Q: Does reaction zone make flowing jets?

20-60%

STAR preliminary

20-60%

track1 - track2|

r.p.

in-plane pair

out-of-plane pair

in between

trigger particlein the selected angular window

Proof of the jet quenchingand the source of v2 at high pT


in-plane pairin between pairout-of-plane pair

0 0 (rad) (rad)

real

/mix

ed flow subtractedpT

trigger > 3GeV/c1 < pT

associated < 2 GeV/c

three curves are fixed bymeasured v2 and resolution

coalescence of jet-fragmentation could be one of the source of v2

PHENIX preliminary PHENIX preliminary


Associated particles pT distributions4 < pT

trig < 6 GeV/c

re-distributed lost energy


Tch : 化学的フリーズアウト温度B : バリオン化学ポテンシャルｓ : ストレンジネス化学ポテンシャルｓ : ストレンジネス平衡

粒子

比

SPS

RHIC

非弾性散乱の終了化学的フリーズアウト


弾性散乱の終了熱力学的フリーズアウト


/dN dy 2 2 2/30S r r A

2

Gluon saturation scale:

/1 GeVS

dN dyQ

r

Tch

/dN dy

S

TC

dNch/d200 400 600

<>

history of temperatureinitial temperaturefrom the energy densityphase transition atcritical temperaturechemical freeze-outtemperaturethermal freeze-outtemperature


early freeze-out

parton flow ?


クォーク数 ( バリオン／メソン）によるスケーリング則


２粒子相関と横方向膨張

検出

器x p

横方向運動量

流体モデル

１粒子分布２粒子相関

熱的

フリ

ーズ

アウ

ト温

度

横方向流体速度


PHENIX, 200GeV Au+Au


coulomb correction


NA49


10

20

30

40

50

60

70

80

90

10

20

30

40

50

60

70

80

90

Vf (

fm3 )

d+Au

p+p

√s=200 GeV

preliminary0

N

(fm

2 )

fmN

V

iii

ff 1

1

,

Mean free path at freeze-out:


(0) RQMD v2.4 original(1) pT vector randomized(2) pT vector aligned with rT vector(3) stronger |pT| vs time correlation(4) apply (2) and (3) simultaneously


The ellipse is still vertical (negative w.r.t. R.P.), but || is smaller than at AGS (closer to circle)


2

0,2

2,

2222

/2

/

ssfinal

xyxyinitial

RR

RRRR

initial final


E895

E895

PHENIX Preliminary

new source imaging technique (coulomb included)indication of the large (exponential/non-gaussian) sourcecore-core / halo-halo / core-halo cross term


PHENIX Preliminary PHENIX Preliminary


blast-wave model (fit)


Spectra Source size (HBT)

nucl-th/0311102 and nucl-th/0310040

Buda-Lund model (fit)


v2 and HBT from AMPT?σ ~ 10 mbσ < 6 mb (~ 3 mb?)


initial geometry and partonic (and hadronic) flow v2 and its relation to jet quenching

(partonic and) hadronic flow + chemical/thermal freeze-out singles (ratio and spectra)

hadronic flow and space-momentum correlation HBT - space-time information

rcnp qgp workshop 2004/11/04shinichi esumi, univ. of tsukuba1 high-energy heavy-ion collisions...

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