18 oct 2003lisa: 2nd warsaw meeting on correlations and resonances - summary1 second warsaw meeting...

18 Oct 2003 Lisa: 2nd Warsaw Meeting on Correlations and Resonances - Summary 1

Second Warsaw Meeting on Correlations & Resonances

• Focused workshop of experts easy to summarize, yes? NO!

– field richly-textured in physics – many directions (present/future, fundamental/phenomelogical, technical(!)) sign of a healthy field

• HBT– theory

• “fundamental”: Lednicky, Csörgő, Mrówczyński, Wilk(1)

• phenomenological/fits: Sinyukov, Csanád, Retière, Tomášik, Wilk(2), Ster, Skowroński, Pratt, Stavinski

– experiment• recent & new data:

– low-energy correlations: Trzaska

– SPS Review: Białkowska

– STAR@RHIC: López-Noriega, Lisa, Panitkin, Chajęcki, Cramer, Janik, Renault

• analysis tools & preparing for future (ALICE@LHC):

– STAR software site: Chaloupka

– detector effects: Malinina, Mikhaylov, Pulvirenti

– generators/afterburners/fitters: Utyuzh, Bysterski, Kisiel

• Resonances

– theory

– experiment

murky/arbitrary/ dangerous division

Discussed a few hours ago. Not summarized hereSimilar themes as HBT – see summary slide


G. Wilk: Information content in singles observables

• (semi)-inclusive single-particle measurement well- described by several seemingly VERY different models

• limited information content to distinguish models

• successful models differ in irrelevant (for single-particle observable) details

• common, crucial ingredients:• conservation laws• inelasticity (K)• possible retention of “memory”/fluctuations (q) generalized entropy maximization)

• Phasespace/conservation law – dominated• 2 parameters required to summarize crude

single-particle spectra

p+pbar, p+p

look to correlation data for more physics-rich information !!


R. Lednicky: Grand correlation overview

Outlined much of what we explore in detail at this Warsaw meeting (& future ones!)

• History of/relationships between HBT, GGLP

• HBT “puzzle” – flash emission?

• asHBT

• PSD

• 3 correlations and chaoticity

• FSI & quantum correlations

• non-id correlations as probe of asymmetries most direct evidence of flow

• Coulomb correlations – “corrections” & -+

-p – large baryon sources

• extracting (spin-dependent!) scattering parameter info from - , etc.

• …

discussed also by A. Stavinsky


W. Trzaska: interesting structures in fission correlations

• Surprising/unexplained “fine structure” in correlated fragment distributions, not appearing in textbooks, or out of smoothly-varying fission barriers in statistical codes

• onset of “spontaneous multifragmentation”?

• novel pre-scission configurations?

• It is not only at RHIC that correlations give theorists the major headaches!

Darth Vader picture

“square” of magic nuclei picture

sorry, slides were not availablein time


H. Białkowska: confluence of signals at SPS

• Answering “the” big issue at SPS required assault from all possible directions

But…trivial isospin effect?

But…strangeness enhancement in pA?






But…QGP neccessary?






But…QGP neccessary?

But…comovers…?




• We find a similar situation @ RHIC, even in our little sub-topic, e.g. to explore “puzzles”

• We will need all of the tools outlined by Richard (and more suggested!) to achieve/claim understanding of space-time dynamics

• Take a look at some of them…


M. López-Noriega: HBT @ 200 GeV AuAu

• new Coulomb procedure (not “correction”)

– consistency check w/ +-

• HBT “puzzle” persists

• More detail: centrality dependence of kT

dependence (incl dAu, pp)

• increased flow for central collisions

• freeze-out source evolution with centrality expansion in Au-Au

– see also talk of F. Retière

RO

(fm

)R

L (f

m)

λ

RS

(fm)

RO / R

S

<kT> GeV/c

centrality

6

6

6

4

4

4

1

1.2

0.8

0.2

0.4

0.6

0.2 0.20.3 0.30.4 0.40.5 0.5

2

2

2+- CF (data)

Theoretical CF (Coulomb, Strong)

Bowler function

Standard function

CF

1

1.5

Qinv (GeV)0.02 0.04 0.06 0.08 0.1 0.12 0.14


S. Panitkin: KK HBT


• charged kaons – continue mT systematic

– expected in flow-dominated scenario

• neutral kaons

– lots of systematic checks

– strongly violate mT systematics (which

are seen at “all” energies, not just in hydro models)

– not solved by strong FSI considerations

• One sanity check, and a new “puzzle”? mt

Pions 5% centrality, Kaons 10% centrality

STAR Preliminary

K0s

Mt (Gev/c)

R

K-

R


(Detour) A. Kisiel – CorrFit tool


• special case of more general treatment where Q.S. and any FSI simultaneously accounted for in fitting function

• fitting tool written for STAR

– C++ class-based, flexible, etc.

– arbitrary source model

– arbitrary correlated system

– identical cuts, phasespace as data

– returns CF, best params, 2 map

• Useful for uniform treatment of measurements for different systems(& systematic studies)


BLv1.5 parameters

Au+Au RHIC

RHIC

P b+P b <S P S >

h+p S P S

T0 [MeV] 214 ±7 139 ± 6 140 ± 3 <ut> 111...000 ±±± 000 ...111 000 ...555555 ±±± 000 ...000666 000...222000 ±±± 000 ...000777 Rs [fm] 888...666 ±±± 000 ...444 777 ...111 ±±± 000 ...222 000...888888 ±±± 000 ...111333 τ0 [fm/c] 666...000 ±±± 000 ...222 555 ...999 ±±± 000 ...666 111 ...444 ±±± 000 ...111 Δτ [fm/c] 0.3 ± 1.2 1.6 ± 1.5 1.3 ± 0.3 Δη 2.3 ±±± 000 ...444 2.1 ± 0.4 1.36 ± 0.02 Tsurf [MeV] 0.5 T 0 fixed 131 ± 8 82 ± 7 Tevap [MeV] 102 ± 11 87 ± 24 - μ0

[MeV] 63 ± 11 μ0

K+ [MeV] 98 ± 19 μ0

p- [MeV] 315 ± 27 2/NDF 158/180 = 0.88 CL 88 %

Ster / Retière: parametric fit to F.O. distrib

• Buda-Lund: special hydro solution w/Hubble flow: good fits to pT spectra, dN/dy, HBT radii

• Freeze-out characteristics

– strong flow, low temperature

– rapid evolution, “flash” emission

• Similar observations from Blast-wave parameterization (Retière)

– though less perfect HBT radius fit

• T0>Tc=170 MeV indication for quarks and hard EOS (???) deconfinement @ RHIC (??)


Csanád / Lisa : Generalization of params to b0

• circular ellipsoidal transverse geometry

• good fits to v2

• suggestive of OOP FO geometry

central midcentral peripheral


Lisa – asHBT at 200 GeV AuAu in STAR

FO =

INIT

• HBT radii oscillate w.r.t. event-wise RP

at all kT, centrality in reasonable (symmetries, trends) way

• OOP source clearly indicated

• Map of initial vs final geometric anisotropy

• probe of evolution timescale from independent direction

– rough model: consistent (~9 fm/c)

• detailed, information-rich probe: overconstraining models? (probably not)


Renault: non-identical particle correlations w/ strange particles

• Challenging, detailed analysis, using topologically-identified (multi-)strange baryons

• probe baryon source size

• opportunity for unique contribution to particle physics

• relevant insight on important issues relating to “partonic collectivity”

• a lot of potential here : watch this spot!

Rp- 2.3 fm

pbar-


Janik : emission asymmetries w/ non-identical particles

• Tool proposed by Lednicky, to probe space-time emission ordering

• requires fine control of anisotropic merging, good understanding of purity

• large errorbars, but consistent with BW “prediction” (not fit)

• more stats, higher pT (TOF), extension to multistrange will help constrain picture

Source ofparticle 1

Source ofparticle 2

Δr* = pair Δr – pair Δt

Δr

r (fm)

Δt<Δr*

out> -K -p K-p

Data -5,60,6 -6,30,6 0,90,7

Blastwave -6,90,3 6,2

RQMD -8,00,6

UrQMD -2,6 -10,6

RM -5,3 -9,7 -

Only statistical errors are presented


Pratt’s response to “Frightening Results from RHIC”

• Frightening: apparently small emission, evolution durations

• To do: further cross-check, again using non-identical particle correlations.

– look at quadrupole moment in addition to dipole moment (previous slide): provides extra measure of Ro, Rs, Rl (well…)

– focus on well-understood Coulomb correlation at large Q

• large Q-bins possible

• sensitive to (Ro/Rs)^2

– also can use, e.g. FSI

• noted negative correlation for attractive/absorptive interaction

– also: Mryczynski: fall of a beautiful rule

Rout=8 fm, Rside = Rbeam = 4 fm


Tomášik : Is F.O. prescription at root of “Frightening” behaviour?

• Sharp FO hypersurface probably unrealistic

• F.O. @ “universal” PSD?

– NO – it’s not universal…

• F.O. @ universal m.f.p. (CERES)?

– better; incorporates chemistry, but not dynamics

• next improvement (BT & UW):

– calculation of “excape probability” based on chemistry, cross-sections, and expansion dynamics

– is it different than an RQMD afterburner??

• sequential delay (bad news for HBT?)

• pions decouple @ 100 MeV

• high PSD may occur @ RHIC

sorry,no pictures


J. Cramer: PSD at 130 GeV AuAu

• Combine spectra, HBT measurements to estimate space-averaged phase-space density

ë

1

RRR

∂ë

ymm∂2

N

E

1)m(

LOS

3

TT

2

∂T

)(⎥⎥⎦

⎤

⎢⎢⎣

⎡⎥⎦

⎤⎢⎣

⎡=⟩⟨

cdd

df

h

Momentum Spectrum HBT “momentumvolume” Vp

PionPurity

Correction

Jacobianto make ita Lorentz

scalar

Average phasespace density


J. Cramer: PSD at 130 GeV AuAu• Combine spectra, HBT measurements to estimate space-

averaged phase-space density

• Break-down of “universal” FO PSD postulated @ SPS

• significant centrality dependence only for most peripheral

• extraction of entropy per particle

– rather low entropies overall

– no threshold behaviour as function of centrality

• Explanation of the “puzzle” or a new one?

• Yuri Sinyukov: no surprise?

0.1 0.2 0.3 0.4 0.5 0.6mT- mp

0.01

0.02

0.05

0.1

0.2

<f>

50 100 150 200 250 300 350NpHparticipantsL3.4

3.6

3.8

4

4.2

4.4

4.6

Sp

?Np

T=90MeV

T=120MeV

T=200MeV

LandauLimit:m=0

BPB


Abounding “features” in AuAu: touch base with reference

Z. Chajęcki : HBT in d-Au and p-p @ 200 GeV

• Beautiful systematics vs centrality, system (pp, dAu, “pAu”), rapidity in dAu

• Same mT dependence in dAu, pp, and AuAu ?? (coincidence or another “puzzle”?)

• Caveat: non-Gaussian CF in dAu, pp

• T. Csörgő: quantify/isolate non-Gaussian behaviour via Edgeworth expansion

– (but this is not the “problem” IMHO)


Preparation for a healthy future – technical tool development

– Pulvirenti: standalone ALICE ITS

– Malinina: PID (several subsystems), 2-track effects in ALICE

– Mikhaylov: 2-track effects at CLAS

– Skowronski: new possibilities in the age of jets

– Ultyuzh, Bysterski: Numerical modelling of HBT

– Chaloupka: dispersal of STAR technology to local sites

Sorry! Time did not permit to give these the attention they deserve.Studies like these build for the future and ensure continued health of our field


Themes / Questions / Puzzles

“Themes”• RHIC data explosive fireball

• unknown: can “real” model describe this consistently from reasonable initial conditions?

• timescales!• assault on STE problem from several exptl fronts:

±±, K±K±, K0K0 correlations• asHBT• non-id correlations• improved Coulomb• combine w/ spectra, v2 (BW, B-L)

• Tightly-coupled feedback theorists↔experimentalists• new data/probes from unique directions• suggestions for new analyses (e.g. “quad moments”)• warnings re: interpretation (e.g. residual correlations,

resonances)• Results from full range/shape of Q (Csorgo, Pratt,

Skowronski)• Increased prominence of PSD• Increased use of FSI as tool (not annoyance)• CF feedback to particle physics

demandconsistency

“Puzzles” & Questions• short timescale puzzles(s) persist

• hydro: good p-space, bad x-space?• is there “time” for hadronic phase?

• probably related – low entropy• K0K0 violation of “mT systematic”

• RAuAu(mT)/Rpp(mT) ~ const – huh??

Previously: “Is there anything beyond ahadronic phase in the data?”

Now: “Where is the hadronic phase in the data?”


A (not really) short tradition continues…

Thank you Jan, Adam, M

ichal,

Piotr and th

e whole Warsa

w

group for a

very useful and well-

run workshop!!


“Internal slide” – order of presentation

• Wilk(1) – minimal information in singles – that’s why we study correlations!• Lednicky – beautiful overview of field – lots of tools/filing out of picture; also: using CFs to extract scattering lengths• Stavinsky – more on this last point (his topic #2)• Trzaska – unexpected/unexplained fine structure in fission correlations correlations give theorists headache @ low E too!• Białkowska – addressing THE crucial question @ SPS: crucial to have systematics – attack the problem from all sides. We must do the same @

RHIC, even in our small sub-topic – use all the tools Richard has layed out (theme)

• López-Noriega - correlations @ 200 GeV (& new Coulomb procedure (not “correction”)); “puzzle” still there; Rs vs cent (also Retiere)• Panitkin – kaon correlations: charge kaons follow mT systematic; neutral kaons ? ; does not appear to be solved by strong FSI considerations• Kisiel – CorrFit – including all correlations naturally in fit of any 2-particle system ( Bowler is special case of this, and could use for K0K0)• Retière – BW intro; BW sort of works @ 130, sort of breaks @ 200; short timescale (theme)• Ster: B-L (~BW fit); similar story• Csanád – generalization of B-L for nonzero impact parameter: v2• Lisa – asHBT; generalization of BW to nonzero impact parameter; new evidence for fast evolution (theme); hadronic stage? (theme)• Janik, Renault – More from unique angle: non-id correlations; ~consistent w/BW – finite shift (probably spatial) – clear evidence of flow• Pratt – all add up to “Frightening results from RHIC”; more info: study quadrupole as well as dipole moment in Coulomb (and other)

correlations – another handle on Ro Rs Rl (theme); directional dependence even in p- - “repulsive” interaction due to absortionsegue to…• Mrówczyński – similar observations an attempt at a beautiful sum rule, and a (now-understood) failure w/ Coulomb (keep w/Pratt)• Tomášik: Also “Frightened”: how to understand this “flash”? – better understand of FO (not CooperFrye): universal PSD?• Cramer: PSD data @ 130 GeV – low entropy & relation to HBT “puzzle” – where is the entropy jump due to QGP? (Rafelski: ~Npart=50)• Sinyukov: time-invariance of APSD <<f>> probing initial state? (Liouville’s theorem?)

• segue: with abounding “mysteries” AuAu, worthwhile to check with “reference” systems:• Chajęcki – pp & dAu reference to AuAu; “link”; beautiful systematics pA, pp, dA; Ratio AuAu/pp (also in Mercedes’) ?; Caveat: nonGaussian• Csörgő – don’t be too simplistic in fitting/characterizing correlations – nonGaussian behaviour; use Edgeworth expansions etc ( theme)• Stavinsky – more warnings: watch out for event-mixing reference and for “residual” correlations• Wilk(2) – more on this last point: residual gamma-gamma correlations from pi0-pi0 correlations

• Readying tools for the future: Ultyuzh, Malinina, Bysterski, Mikhaylov, Skowronski, Chaloupka, Pulvirenti

18 oct 2003lisa: 2nd warsaw meeting on correlations and resonances - summary1 second warsaw meeting...

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