1 / 39

Femtoscopy in heavy ion collisions - Part 2

!. !. “School” lecture. Femtoscopy in heavy ion collisions - Part 2. Mike Lisa The Ohio State University. Lecture I - basics and sanity check Motivation (brief) Formalism (brief reminder) accessible geometric substructure Some experimental details 2 decades * of data systematics

candie
Download Presentation

Femtoscopy in heavy ion collisions - Part 2

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ! ! “School” lecture Femtoscopy in heavy ion collisions - Part 2 Mike Lisa The Ohio State University The Berkeley School - Femtoscopy - malisa

  2. Lecture I - basics and sanity check Motivation (brief) Formalism (brief reminder) accessible geometric substructure Some experimental details 2 decades* of data systematics system size: AB, |b|, Npart... system shape: (P,b) Lecture II - dynamics (insanity check?) data systematics [cnt’d] boost-invariance?: Y transverse dynamics: kT, mT new substructure: m1≠m2 Interpretations (& puzzles) Messages from data itself Model comparisons Prelim. comparison: pp, dA Summary Outline * in time and in sNN The Berkeley School - Femtoscopy - malisa

  3. ? in-plane-extended Motivation Formalism Experiment Trends Models out-of-plane-extended Strongly-interacting 6Li released from an asymmetric trap O’Hara, et al, Science 298 2179 (2002) What can we learn? transverse FO shape + collective velocity  evolution time estimate check independent of RL(pT) Teaney, Lauret, & Shuryak nucl-th/0110037 The Berkeley School - Femtoscopy - malisa

  4. RY Spectra RX Motivation Formalism Experiment Trends Models v2 HBT Blast wave : the truth, or something like it F. Retière , QM04 F. Retière & MAL PRC70 044907 (2004) • generalized anisotropic BW in ubiquitous use • consistent picture capturing essence of data • homo. region  “whole source” with realistic flow gradients The Berkeley School - Femtoscopy - malisa

  5. out side Motivation Formalism Experiment Trends Models long out-side in no-flow scenario... U. Wiedemann PR C57 266 (1998) MAL, U. Heinz, U. Wiedemann PL B489 287 (2000) Extracting FO shape/size • 2nd - order oscillations in radii (n>2 negligible) • characterize each kT bin with 7 numbers: R2os,0 = 0 by symmetry [Heinz, Hummel, MAL, Wiedemann PRC66, 044903] F. Retière & MAL PRC70 044907 (2004) The Berkeley School - Femtoscopy - malisa

  6. Motivation Formalism Experiment Trends Models in no-flow scenario... U. Wiedemann PR C57 266 (1998) MAL, U. Heinz, U. Wiedemann PL B489 287 (2000) Extracting FO shape/size • 2nd - order oscillations in radii (n>2 negligible) • characterize each kT bin with 7 numbers: R2os,0 = 0 by symmetry [Heinz, Hummel, MAL, Wiedemann PRC66, 044903] /2 continues to be good approximation even with flow! (~30%) F. Retière & MAL PRC70 044907 (2004) The Berkeley School - Femtoscopy - malisa

  7. Motivation Formalism Experiment Trends Models in no-flow scenario... U. Wiedemann PR C57 266 (1998) MAL, U. Heinz, U. Wiedemann PL B489 287 (2000) Extracting FO shape/size • 2nd - order oscillations in radii (n>2 negligible) • characterize each kT bin with 7 numbers: R2os,0 = 0 by symmetry [Heinz, Hummel, MAL, Wiedemann PRC66, 044903] continues to be good approximation even with flow! (~30%) F. Retière & MAL PRC70 044907 (2004) The Berkeley School - Femtoscopy - malisa

  8. central collisions mid-central collisions Motivation Formalism Experiment Trends Models peripheral collisions Measured final source shape STAR, PRL93 012301 (2004) Expected evolution: ? The Berkeley School - Femtoscopy - malisa

  9. 2.5 Rfinal/Rinitial initial= final 2 Motivation Formalism Experiment Trends Models 1.5 1 0 100 200 300 400 Npart Evolution of size and shape @RHIC STAR PRC71 044906 (2005) STAR PRL93 012301 (2004) ~ x2 size increase ~ 1/2 shape reduction Initial size/shape estimated by Glauber calculation The Berkeley School - Femtoscopy - malisa

  10. Evolution ahead Detour The Berkeley School - Femtoscopy - malisa

  11. Motivation Formalism Experiment Trends Models asHBT systematics (1/100 * sNN) •  = 0-2 (not 0-)first-order plane used • similar oscillations in purely transverse radii • out-long & side-long? • new symmetry! Au+Au sNN = 2.3 GeV; b5 fm E895, PLB496 1 (2000) The Berkeley School - Femtoscopy - malisa

  12. Motivation Formalism Experiment Trends Models out-side-long versus x-y-z side y K • Source in b-fixed system: (x,y,z) • Space/time entangled in pair system (xO,xS,xL) out f x b (several terms vanish @ pT = y = 0) U. Wiedemann, PRC 57, 266 (1998) MAL, U. Heinz, U. Wiedemann PLB 489, 287 (2000) The Berkeley School - Femtoscopy - malisa

  13. y 2nd-harmonic oscillations from elliptical transverse shape x b 1st-harmonic oscillations: spatial tilt angle qS y x qs z (Beam) Coordinate space! First-order information in HBT(f) The Berkeley School - Femtoscopy - malisa

  14. f () Data: p- correlation functionsAu(4 AGeV)Au, b4-8 fm 2D projections 1D projections, f=45° C(q) out side long lines: projections of 3D Gaussian fit • 6 components to radius tensor: i, j = o,s,l E895, PLB 496 1 (2000) The Berkeley School - Femtoscopy - malisa

  15. f () Cross-term radii Rol, Ros, Rslquantify “tilts” in correlation functions fit results to correlation functions Mike Lisa: thicker lines!!! bigger symbols!! have 2 GeV handy Lines: Simultaneous fit to HBT radii to extract underlying geometry The Berkeley School - Femtoscopy - malisa

  16. qS=47° qS=33° qS=37° y z y y z z x x ’ x ’ x x ’ x similar to naïve overlap: b~5 fm 3 fm Images of p--emitting sources (scaled ~ x1014) Mike Lisa: 1 fm = 1/4” 2 AGeV 4 AGeV 6 AGeV Large, positive tilt angles The Berkeley School - Femtoscopy - malisa

  17. p+ 6 AGeV z (fm) x (fm) RQMD Au(2GeV)Au Opposing average tilts in p, x & the physics of p flow • p “antiflow” (negative tilt in p-space) • x-space tilt in positive direction •  non-hydro nature of p flow (@ AGS) B. Caskey, E895 The Berkeley School - Femtoscopy - malisa

  18. AGS: FO  init RHIC: FO < init (approximately same centrality) sNN (GeV) • transverse shape: • non-trivial excitation function • increased flow*time  rounder FO geometry @ RHIC • insufficient [flow]x[time] to become in-plane The Berkeley School - Femtoscopy - malisa

  19.  (o) y x qs sNN (GeV) z (Beam) AGS • transverse shape: • non-trivial excitation function • increased flow*time  rounder FO geometry @ RHIC • insufficient [flow]x[time] to become in-plane • Spatial orientation: • another handle on flow & time • HUGE tilts @ AGS!! • RHIC? • QGP-induced orientation? STAR: soon ? ? The Berkeley School - Femtoscopy - malisa

  20. v1 predictions (QGP invoked) x-p transverse-longitudinal coupling may be affected in early (v1) stage L.P. Csernai, D. Rohrich: Phys. Lett. B 458 (1999) 454 J. Brachmann et al., Phys. Rev. C. 61 024909 (2000) The Berkeley School - Femtoscopy - malisa

  21.  (o) y x qs sNN (GeV) z (Beam) AGS • transverse shape: • non-trivial excitation function • increased flow*time  rounder FO geometry @ RHIC • insufficient [flow]x[time] to become in-plane • Spatial orientation: • another handle on flow & time • HUGE tilts @ AGS!! • RHIC? • QGP-induced orientation? • requires true 3D dynamical model (explicitly non-B.I.) STAR: soon ? ? ? The Berkeley School - Femtoscopy - malisa

  22. Spectra Evolution ahead v2 Resume legal speed HBT x2 size increase & decreasing deformation -- ?collective expansion? -- The Berkeley School - Femtoscopy - malisa

  23. Decreasing R(pT) • usually attributed to collective flow • flow integral to our understanding of R.H.I.C.; taken for granted • femtoscopy the only way to confirm x-p correlations – impt check Kolb & Heinz, QGP3 nucl-th/0305084 The Berkeley School - Femtoscopy - malisa

  24. Decreasing R(pT) • usually attributed to collective flow • flow integral to our understanding of R.H.I.C.; taken for granted • femtoscopy the only way to confirm x-p correlations – impt check • Non-flow possibilities • cooling, thermally (not collectively) expanding source • combo of x-t and t-p correlations early times: small, hot source late times: large, cool source The Berkeley School - Femtoscopy - malisa

  25. Decreasing R(pT) • usually attributed to collective flow • flow integral to our understanding of R.H.I.C.; taken for granted • femtoscopy the only way to confirm x-p correlations – impt check • Non-flow possibilities • cooling, thermally (not collectively) expanding source • combo of x-t and t-p correlations MAL et al, PRC49 2788 (1994) The Berkeley School - Femtoscopy - malisa

  26. Decreasing R(pT) • usually attributed to collective flow • flow integral to our understanding of R.H.I.C.; taken for granted • femtoscopy the only way to confirm x-p correlations – impt check • Non-flow possibilities • cooling, thermally (not collectively) expanding source • combo of x-t and t-p correlations • hot core surrounded by cool shell • important ingredient of Buda-Lund hydro picturee.g. Csörgő & LörstadPRC54 1390 (1996) The Berkeley School - Femtoscopy - malisa

  27. Each scenario generates x-p correlations • Decreasing R(pT) • usually attributed to collective flow • flow integral to our understanding of R.H.I.C.; taken for granted • femtoscopy the only way to confirm x-p correlations – impt check but… x2-p correlation: yes x-p correlation: yes • Non-flow possibilities • cooling, thermally (not collectively) expanding source • combo of x-t and t-p correlations • hot core surrounded by cool shell • important ingredient of Buda-Lund hydro picturee.g. Csörgő & LörstadPRC54 1390 (1996) x2-p correlation: yes x-p correlation: no t x2-p correlation: yes x-p correlation: no The Berkeley School - Femtoscopy - malisa

  28. pT T • flow-dominated “models” can reproduce soft-sector x-space observables • imply short timescales • however, are we on the right track? [flow] • puzzles?  check your assumptions! • look for flow’s “special signature”x-p correlation • In flow pictures, low-pT particles emitted closer to source’s center (along “out”) • non-identical particle correlations(FSI at low v) probe: • (x1-x2)2 (as does HBT) • x1-x2  K p [click for more details on non-id correlations] F. Retiere & MAL, nucl-th/0312024 Csanád, Csörgő, Lörstad nucl-th/0311102 and nucl-th/0310040 The Berkeley School - Femtoscopy - malisa

  29. T T x (fm) QM02 x (fm) A. Kisiel (STAR) QM04 • extracted shift in emission point x1-x2 consistent w/ flow-dominated blastwave • In flow pictures, low-pT particles emitted closer to source’s center (along “out”) • non-identical particle correlations(FSI at low v) probe: • (x1-x2)2 (as does HBT) • x1-x2 The Berkeley School - Femtoscopy - malisa

  30. LPSW(05) - DATA in color-- experimentalist’s plot Motivation Formalism Experiment Trends Models what agreement!! (what agreement?) Strong flow confirmed by all expts... The Berkeley School - Femtoscopy - malisa

  31. Motivation Formalism Experiment Trends Models Strong flow confirmed by all expts... Central (~10%) AuAu (PbPb) collisions at y~0 The Berkeley School - Femtoscopy - malisa

  32. Motivation Formalism Experiment Trends Models Another implication of strong flow: ~mT scaling The Berkeley School - Femtoscopy - malisa

  33. inconsistent with boost-invariance Motivation Formalism Experiment Trends Models PHOBOS nucl-ex/0410022 Some longitudinal systematics consistent with boost-invariance The Berkeley School - Femtoscopy - malisa

  34. beam “Dynamic” BI without “Chemical” BI ? Only femtoscopy can tell! The Berkeley School - Femtoscopy - malisa

  35. beam “Dynamic” BI without “Chemical” BI ? Only femtoscopy can tell! The Berkeley School - Femtoscopy - malisa

  36. sizes and offsets in impact parameter and longitudinal directions C E877, Miskowiec CRIS’98 nucl-ex/9808003 p-- Motivation Formalism Experiment Trends Models 10 fm qX (GeV/c) b qY (GeV/c) qZ (GeV/c) z Greater detail - -p correlations @ AGS The Berkeley School - Femtoscopy - malisa

  37. Summary - very brief.More in Friday’s discussion The Berkeley School - Femtoscopy - malisa

  38. R = 1.2 (fm)•A1/3 Summary - very brief.More in Friday’s discussion • Part I • space-time THE special aspect of our field • systematics pass sanity check • Data show remarkable consistency • HUGE range of systematics, b (mag and direction), pT, m1m2, y, AB • size • shape • orientation in 3D space • detailed dynamic substructure in all directions including shifts • At a given s, flow-dominated scenario strongly indicated. Can work (Blast Wave) • (Unfortunately?) 2 decades of experimental effort over 2 decades of s • very little changes • scaling with final multiplicity, not A... progress? The Berkeley School - Femtoscopy - malisa

  39. final words (for today) • We are measuring system geometry • Space and time geometry (in detail) hardly changesAGS RHIC • This astounding fact is the 0th HBT Puzzle, and much more important/troubling than the 1st Puzzle (model failures) • generic expectation: entropy & latent heat / “softest point” • Given the importance of spacetime to RHI and QGP, this deserves our attention, despite its being a wart on otherwise “perfect” story The Berkeley School - Femtoscopy - malisa

More Related