p-X correlations at RHIC

Michal Šumbera, NPI ASCR, Prague, Czech Republic 1st ALICE Physics week, Erice 9/12/05

correlations at RHICcorrelations at RHIC

Michal Šumbera

Nuclear Physics Institute ASCR Řež/Prague

ALICE Physics week, Erice 5th - 9th December, 2005


+ - K+ K- K0S p p

+

-

- K+

K-

- - K0S

p

p

prelim or final result available

RHIC femtoscopy matrixRHIC femtoscopy matrix

P. Chaloupka, nucl-ex/0510064

Nucl.Phys.A749:283-286,2005

P. Chaloupka, nucl-ex/0510064

Nucl.Phys.A749:283-286,2005 G. Renault, hep-ex/0406066

G. Renault, PhD thesis

G. Renault, hep-ex/0406066

G. Renault, PhD thesis

Phys.Rev.Lett.91:262302,2003J.Phys.G30:S1059-S1064,2004 A. Kisiel, PhD thesis

Phys.Rev.Lett.91:262302,2003J.Phys.G30:S1059-S1064,2004 A. Kisiel, PhD thesis


Measuring production Measuring production offset by kinematic offset by kinematic

selectionselection• If space-time ordering,

select between two configurations– One particle catching up– Particles moving away from

each other

• Final state interactions yield different correlations for these two configuration

• Interaction timeInteraction time is is shortershorter

• Weaker correlationWeaker correlation

A) faster particle flying away

B) faster particle catching up

• Interaction timeInteraction time is is longerlonger

• Stronger correlationStronger correlation

R.Lednický, V. Lyuboshitz, B. Erazmus, D. Nouais, Phys.Lett. B 373(1996)30.R.Lednický, V. Lyuboshitz, B. Erazmus, D. Nouais, Phys.Lett. B 373(1996)30.

R.Lednický, V. Lyuboshitz, Sov.J. Nucl.Phys. 20(1982)770.R.Lednický, V. Lyuboshitz, Sov.J. Nucl.Phys. 20(1982)770.

S. Voloshin, R.Lednický, S. Panitkin, Nu Xu, Phys.Rev.Lett.79(1997)4766.S. Voloshin, R.Lednický, S. Panitkin, Nu Xu, Phys.Rev.Lett.79(1997)4766.


Effects of transverse flowEffects of transverse flow• Correlation between

momentum and emission point

• Effective reduction of source size and shift in average emission point

• Effect increases with mT

Non-identical correlations can test flow by measuring sizes and shifts of the sources

PionpT= 0.15 GeV/c

ProtonpT = 1. GeV/c

Ξ-

pT = 1.4 GeV/cΩ-

pT = 1.8 GeV/c

Emission points from Blast-waveβT = 0.73 for all species

Rout

Rside

R(R())R(p)R(p)R(R())R(R())


• ,K, p <T> at 200 GeV > 62 GeV Tfo at 200 GeV =62 GeV

• <T> at 200 GeV = 62 GeV Tfo at 200 GeV >62 GeV

• Temperature Tfo is higher for baryons with higher strange quark content for Blast-wave fits.

• Spectral shapes are different.

Tfo from a Blast-Wave is not same as the Temperature from a Hydro Model.

Most Central Collisions

0.13

--productionproduction @RHIC: radial @RHIC: radial flowflow

Tem

per

atu

re T

fo (G

eV)

Sevil Salur QM’05

nucl-ex/0509036

Sevil Salur QM’05

nucl-ex/0509036

T=100 MeV

Tfo=132 MeV


What the hydro tell us about What the hydro tell us about multistrange baryons at RHICmultistrange baryons at RHIC

Heavy hadrons, which are particularly sensitive to radial flow effects, require the additional collective “push” created by resonant (quasi)elastic interactions during the fairly long-lived hadronic rescattering stage between Tcr and Td

U. Heinz, J. Phys. G31,S717, 2005U. Heinz, J. Phys. G31,S717, 2005


Phys. Rev. Lett. 92 (2004) 052302 Au+Au √sNN=200 GeV

Au+Au √sNN=62 GeV

STAR Preliminary

--productionproduction @RHIC: elliptic @RHIC: elliptic flowflow

pT/n (GeV/c)0 1 2

2

2

2

1 2 ( )cos(2 )

1 2 ( )cos(2 )

1 2 cos(2 )

q

T

nq qT

q Tq

q

dNv p

d

v p

pn v

n

Sevil Salur QM’05Sevil Salur QM’05

Au+Au √sNN=200 GeV

Michal Šumbera, NPI ASCR, Prague, Czech Republic 1st ALICE Physics week, Erice 9/12/05MeVmmm 70)()1530(

Resonant states in Resonant states in systemsystem

*

*

*

*


p

*

K*

p

K

K

p

Che

mic

al f

reez

e-ou

t

KK

RelevantCrossSections:*{Kp}K*{K}*{}{p}*{}

σ σp σrescattering of K (+K ) in the medium should be higher than that of (K+p ).

K*) < *) enhanced the rescattering probability of K*.

Non-zero lifetime between chemical and thermal freeze-out regeneration σ(K*) σ(*)

Resonances: Resonances: rescattering and rescattering and recombinantionrecombinantion

Life time [fm/c] :Life time [fm/c] :(1020) = 47 (1020) = 47 (1520) = 13(1520) = 13 (1385) = (1385) = 55 K(892) =K(892) = 4 4

Npart

Sevil Salur QM’05, nucl-ex/0509036 Sevil Salur QM’05, nucl-ex/0509036


Why Why correlations?correlations?

• (as well as other multi strange baryons) may have thermal freeze-out behaviour differing from the other hadrons: e.g. early decoupling?

•Why is elliptic flow comparable to other hadrons? Is that all suggesting early partonic collectivity?

•What is the production mechanism of (1520) resonance?


pp

Topological reconstruction Topological reconstruction ofof

pT= (1 , 3)

GeV/c

: y = (-0.5 , 0.5) p

T= (0.15 , 0.8) GeV/c

DcaXiToPrimVertex < 0.55cm DcaV0ToPrimVertex > 0.1cmDcaBachelorToPrimVertex > 1.5cm

..BN ..BN


0-10% ~ 460k

10-40% ~ 410k

40-80% ~ 150k

Centrality bins:

200GeV AuAu200GeV AuAuY2+Y4: 57M events

Analyzed Analyzed datadata

0-10% ~ 39k

10-40% ~ 110k

40-80% ~ 40k

Centrality bins:

62GeV AuAu62GeV AuAu12.7M events

~ 18k

Minimum bias:

200GeV dAu200GeV dAu10M events

..BN ..BN


States in unlike-sign States in unlike-sign systemsystem

200 GeV pp

**(1530)(1530)

200 GeV dAu MinBias

STAR preliminary

STAR preliminary

R. Witt SQM’04

R. Witt SQM’04

*

*

*

*


62 GeV AuAu 0-80%

200 GeV dAu MinBias

STAR preliminary

STAR preliminary

**(1530)(1530)


*

*

*

*


62 GeV AuAu

200 GeV AuAu: Y2+Y4

STAR preliminary

STAR preliminary

**(1530)(1530)


*

*

*

*


STAR preliminary

STAR preliminary

200 GeV AuAu 10-40%: Y2+Y4

200 GeV AuAu 0-10%: Y2+Y4

**(1530)(1530)


*

*

*

*



STAR preliminary

STAR preliminary

200 GeV AuAu 10-40%: Y2+Y4

200 GeV AuAu 40-80%: Y2+Y4

**(1530)(1530)

*

*

*

*


M

mmMmmMk

2

])([])([ 2/1222/122*

STAR preliminary

STAR preliminary

**(1530)(1530)

200 GeV dAu MinBias200 GeV dAu MinBias

From mFrom m to to

C(kC(k**))

**


M

mmMmmMk

2

])([])([ 2/1222/122*

STAR preliminarySTAR preliminary

**(1530)(1530)

200 GeV AuAu 0-80%200 GeV AuAu 0-80%

STAR preliminary

STAR preliminary

**

From mFrom m to to

C(kC(k**))


-- systematicssystematics: : experimentexperiment

• No significant energy dependence

•Strong system dependence


like-sign vs unlike-sign

central vs peripheral

++ & --•consistent•Coulomb-dominated

+- & -+•consistent•Coulomb + strong

Expected centralitydependence • “*” sensitive! *

-- correlations in Au+Aucorrelations in Au+Au @ @ 200 GeV200 GeV

P. Chaloupka, QM’05

P. Chaloupka, QM’05


Spherical harmonics Spherical harmonics decomposition of non-identical decomposition of non-identical

particle correlationsparticle correlations

Z. Chajecki , T.D. Gutierrez , M.A. Lisa and M. López-Noriega, nucl-ex/0505009

Z. Chajecki , T.D. Gutierrez , M.A. Lisa and M. López-Noriega, nucl-ex/0505009

*

*

*

*

2*2*2***

arctan

)cos(

OUT

SIDE

TOT

LONG

LONGSIDEOUTTOT

k

k

k

k

kkkkk

binsall

iiiiimlml kCYkA

.*

,cos*

, ),cos,(),(4

)(

*** ppk


Spherical harmonics Spherical harmonics decomposition of non-identical decomposition of non-identical

particle correlationsparticle correlations

• Different Alm

correspond

to different symmetries of

the source

• A00 - monopole size

• A11 - dipole shift in

out-direction

• A2m – quadrupole shape

• .....


Accessing asymmetryAccessing asymmetry

• A11 ≠ 0 in

correlation regions

Asymmetry in the average emission point between

and

• Correct ordering (A

11 0) , i.e. in the

“right” direction (cf BW)

P. Chaloupka, WPCF’05

P. Chaloupka, WPCF’05


Model comparisonModel comparison

FSI: S.Pratt & S.Petricioni,

Phys.Rev. C68,054901(2003)

Emission points from:

• BW constrained by CF data

• RQMD

• Difference between measured and calculated CF in the * region is under investigation

• Observed shift agrees qualitatively with flow scenario.

l


Model comparison: Model comparison: RQMD without FSIRQMD without FSI

Petr Chaloupka and Fabrice Retière: NSD LBNL Annual Report 2004

http://www.lbl.gov/nsd/resources/annualreportcontributionsall/chaloupka.pdf

Petr Chaloupka and Fabrice Retière: NSD LBNL Annual Report 2004

http://www.lbl.gov/nsd/resources/annualreportcontributionsall/chaloupka.pdf


Remaining technical Remaining technical challengeschallenges

• Non-flat baseline issue• Wide k* structure in CF

possible source: flow, detector effects are currently being investigated

• Using fake s to construct correlation function with similar baseline behaviour for corrections

fake s


Summary

• First high statistics measurements of correlations were presented.

• Coulomb and strong FSI were observed.• Very good sensitivity to source size in peak

was found. Theoretical input needed.• New spherical harmonics representation of

data allowed us to observe clear shift between average emission points of and sources in qualitative agreement with transversally expanding source.

• Prospect for the same type measurement at LHC seems good!!


The STARSTAR CollaborationU.S. Labs:

Argonne, Lawrence Berkeley, and Brookhaven National Labs

U.S. Universities: UC Berkeley, UC Davis, UCLA, Caltech, Carnegie Mellon, Creighton, Indiana, Kent State, MIT, MSU, CCNY, Ohio State, Penn State, Purdue, Rice, Texas A&M, UT Austin, Washington, Wayne State, Valparaiso, Yale

Brazil: Universidade de Sao Paolo

China: IHEP - Beijing, IPP - Wuhan, USTC,Tsinghua, SINAP, IMP Lanzhou

Croatia: Zagreb University

Czech Republic: Nuclear Physics Institute

England:University of Birmingham

France: Institut de Recherches Subatomiques Strasbourg, SUBATECH - Nantes

Germany: Max Planck Institute – Munich University of Frankfurt

India:Bhubaneswar, Jammu, IIT-Mumbai, Panjab, Rajasthan, VECC

Netherlands:NIKHEF/Utrecht

Poland:Warsaw University of Technology

Russia: MEPHI – Moscow, LPP/LHE JINR – Dubna, IHEP – Protvino

South Korea:Pusan National University

Switzerland:University of Bern

STARSTAR


Back up slides


Early freeze-out ?Early freeze-out ?

• Is this due to early freeze-out? (Could we tell?)

• Competing changes – small overall effect

• Assumed early freeze-out scenario – small effect on CF BW parameters

T[Mev] 103 103 150 0,93 0,93 0,75

R[fm] 10,3 10,3 96,9 6,9 52 2 2

early freeze-out

[fm]fm]


M

mmMmmMk

2

])([])([ 2/1222/122*

**(1530)(1530)

200 GeV AuAu 40-80%200 GeV AuAu 40-80%

STAR preliminary

STAR preliminary

From mFrom m to C(k to C(k**))

**


M

mmMmmMk

2

])([])([ 2/1222/122*

**(1530)(1530)

200 GeV AuAu 10-40%200 GeV AuAu 10-40%

STAR preliminary

STAR preliminary


**


M

mmMmmMk

2

])([])([ 2/1222/122*

**(1530)(1530)

200 GeV AuAu 0-10%200 GeV AuAu 0-10%

STAR preliminary

STAR preliminary


**


pion

Kaon

proton

Distribution of emissionpoints at a given emission momentum.

Particles are correlated when their velocities are similar.

Keep velocity constant: - Left: vx = 0.73c, vy = 0 - Right: vx = 0.91c, vy = 0

Dashed lines: average emission radius.

RRxx(()) RRxx(K)(K)RRxx(p)(p)

px = 0.15 GeV/c

px = 0.53 GeV/c px = 1.07 GeV/c

px = 2.02 GeV/cpx = 1.01 GeV/c

px = 0.3 GeV/c

Looking at Looking at different different particlesparticles


Entropy drives the Entropy drives the strangenessstrangeness yield yield

dNch/dη instead of Npart

Correlated to the entropy of the system!

Sevil Salur QM’05

nucl-ex/0509036

Sevil Salur QM’05

nucl-ex/0509036

J.Stachel: (1530)/(1321) = 0.56 0.025 for 0-10% AuAu @ 200GeV

J.Stachel: (1530)/(1321) = 0.56 0.025 for 0-10% AuAu @ 200GeV

Michal Šumbera, NPI ASCR, Prague, Czech Republic 1st ALICE Physics week, Erice 9/12/05LPSW: nucl-ex/0505014 LPSW: nucl-ex/0505014

•Final geometry - particle density (entropy)- drives the radii, not the initial geometry!!

•Breaks down s < 5 GeV

Entropy drives the Entropy drives the pionpion emission emission radii radii


),(),(

),(),()(

44

44

bbbaaaba

babbbaaabaabP xpsxpsxdxd

xxrxpsxpsxdxdrS

Distribution of relative positions of particles with identical velocities and total momentum P

Two-particle correlation Two-particle correlation functionfunction

CP

ab(q )

d6Nab /(dpa3dpb

3)

d3Na /dpa3 d3Nb /dpb

3 ba

ba

ppq

ppP

23 ),()()( rqrSrdqC abP

abP

N.B. prime means in the pair CMS frame

: Space-time emission function of particle i

),( iii xps

Two particle wave funcion(QS+FSI)

p-X correlations at RHIC

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Transcript of p-X correlations at RHIC