Second Warsaw Meeting on Correlations & Resonances

1. Second Warsaw Meeting on Correlations & Resonances Discussed a few hours ago. Not summarized here Similar themes as HBT – see summary slide • 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 Lisa: 2nd Warsaw Meeting on Correlations and Resonances - Summary

2. G. Wilk: Information content in singles observables p+pbar, p+p • (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 • look to correlation data for more physics-rich information !! Lisa: 2nd Warsaw Meeting on Correlations and Resonances - Summary

3. 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 Lisa: 2nd Warsaw Meeting on Correlations and Resonances - Summary

4. W. Trzaska: interesting structures in fission correlations Darth Vader picture • 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! “square” of magic nuclei picture sorry, slides were not available in time Lisa: 2nd Warsaw Meeting on Correlations and Resonances - Summary

5. 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? Lisa: 2nd Warsaw Meeting on Correlations and Resonances - Summary

6. H. Białkowska: confluence of signals at SPS But… QGP neccessary? • Answering “the” big issue at SPS required assault from all possible directions But… trivial isospin effect? But… strangeness enhancement in pA? Lisa: 2nd Warsaw Meeting on Correlations and Resonances - Summary

7. H. Białkowska: confluence of signals at SPS But… QGP neccessary? • Answering “the” big issue at SPS required assault from all possible directions But… trivial isospin effect? But… strangeness enhancement in pA? But… comovers…? Lisa: 2nd Warsaw Meeting on Correlations and Resonances - Summary

8. H. Białkowska: confluence of signals at SPS • Answering “the” big issue at SPS required assault from all possible directions • 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… Lisa: 2nd Warsaw Meeting on Correlations and Resonances - Summary

9. M. López-Noriega:  HBT @ 200 GeV AuAu centrality λ 0.6 CF 1.5 0.4 +- CF (data) Theoretical CF (Coulomb, Strong) Bowler function Standard function 0.2 6 6 RO (fm) RS (fm) 4 4 1 2 2 0.02 0.04 0.06 0.08 0.1 0.12 0.14 Qinv (GeV) 6 1.2 RL (fm) RO / RS 4 1 2 0.8 0.2 0.3 0.4 0.5 0.2 0.3 0.4 0.5 <kT> GeV/c • 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 Lisa: 2nd Warsaw Meeting on Correlations and Resonances - Summary

10. S. Panitkin: KK HBT  R Pions 5% centrality, Kaons 10% centrality STAR Preliminary R  K0s mt K- Mt (Gev/c) • new Coulomb procedure (not “correction”) • 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”? Lisa: 2nd Warsaw Meeting on Correlations and Resonances - Summary

11. (Detour) A. Kisiel – CorrFit tool • new Coulomb procedure (not “correction”) • 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) Lisa: 2nd Warsaw Meeting on Correlations and Resonances - Summary

12. 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 (??) Lisa: 2nd Warsaw Meeting on Correlations and Resonances - Summary

13. Csanád / Lisa : Generalization of params to b0 • circular  ellipsoidal transverse geometry • good fits to v2 • suggestive of OOP FO geometry central midcentral peripheral Lisa: 2nd Warsaw Meeting on Correlations and Resonances - Summary

14. Lisa – asHBT at 200 GeV AuAu in STAR FO = INIT • HBT radii oscillate w.r.t. event-wiseRPat 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) Lisa: 2nd Warsaw Meeting on Correlations and Resonances - Summary

15. Renault: non-identical particle correlations w/ strange particles Rp-  2.3 fm pbar- • 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! Lisa: 2nd Warsaw Meeting on Correlations and Resonances - Summary

16. Janik : emission asymmetries w/ non-identical particles Source of particle 1 Source of particle 2 Dr Dt r (fm) Dr* = gpair (Dr– bpair Dt) • 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 Lisa: 2nd Warsaw Meeting on Correlations and Resonances - Summary

17. Pratt’s response to “Frightening Results from RHIC” Rout=8 fm, Rside = Rbeam = 4 fm • 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 Lisa: 2nd Warsaw Meeting on Correlations and Resonances - Summary

18. Tomášik : Is F.O. prescription at root of “Frightening” behaviour? sorry, no pictures • 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 Lisa: 2nd Warsaw Meeting on Correlations and Resonances - Summary

19. J. Cramer: PSD at 130 GeV AuAu • Combine spectra, HBT measurements to estimate space-averaged phase-space density Average phasespace density HBT “momentumvolume” Vp PionPurityCorrection Momentum Spectrum Jacobianto make ita Lorentzscalar Lisa: 2nd Warsaw Meeting on Correlations and Resonances - Summary

20. 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? Lisa: 2nd Warsaw Meeting on Correlations and Resonances - Summary

21. Abounding “features” in AuAu: touch base with referenceZ. 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) Lisa: 2nd Warsaw Meeting on Correlations and Resonances - Summary

22. 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 Lisa: 2nd Warsaw Meeting on Correlations and Resonances - Summary

23. 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 • “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?? demand consistency Previously: “Is there anything beyond a hadronic phase in the data?” Now: “Where is the hadronic phase in the data?” Lisa: 2nd Warsaw Meeting on Correlations and Resonances - Summary

24. A (not really) short tradition continues… Thank you Jan, Adam, Michal, Piotr and the whole Warsaw group for a very useful and well-run workshop!! Lisa: 2nd Warsaw Meeting on Correlations and Resonances - Summary

25. “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 absortionsegue 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 Lisa: 2nd Warsaw Meeting on Correlations and Resonances - Summary