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The most famous femtoscopic systematic

The most famous femtoscopic systematic. Mike Lisa Ohio State University. Plan: wherefore, whence, whither. Motivation (wherefore) Femtoscopy: two decades of progress (whence) 2 x s NN in 20 years p T (m T ) dependence (whence)

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The most famous femtoscopic systematic

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  1. The most famousfemtoscopic systematic Mike Lisa Ohio State University Wayne State University 22 Nov 05

  2. Plan: wherefore, whence, whither • Motivation (wherefore) • Femtoscopy: two decades of progress (whence) • 2xsNN in 20 years • pT (mT) dependence (whence) • spatial substructure: evidence of strong collective flow in R.H.I.C. • similar behaviour in (very) low-energy H.I.C. • unexpected (??) scaling w.r.t. pp • pp in some more detail: SHD and long-range correlations (whither) • (in progress) • Summary Wayne State University 22 Nov 05

  3. STAR, PRC66 (2002) 034904 STAR, PRL93 (2004) 252301 Spacetime - an annoying bump on the road to Stockholm? • Non-trivial space-time - the hallmark of rhic • Initial state: dominates further dynamics • Intermediate state: impt element in exciting signals • Final state: • Geometric structural scale is THE defining feature of QGP & r.h.i.c Wayne State University 22 Nov 05

  4. Ann.Rev.Nucl.Part.Sci. 46 (1996) 71 Spacetime - an annoying bump on the road to Stockholm? • Non-trivial space-time - the hallmark of rhic • Initial state: dominates further dynamics • Intermediate state: impt element in exciting signals • Final state: • Geometric structural scale is THE defining feature of QGP & r.h.i.c • Temporal scale sensitive to deconfinement transition (?) Wayne State University 22 Nov 05

  5. The Bottom line… if a pion is emitted, it is more likely to emit another pionwith very similar momentumif the source is small Creation probability r(x,p) = U*U F.T. of pion source Measurable! probingsource geometry through interferometry p1 r1 x1 p source r(x) 1 m x2 r2 p2 experimentally measuring this enhanced probability: quite challenging 5 fm Wayne State University 22 Nov 05

  6. Au+Au R ~ 6 fm p+p R ~ 1 fm d+Au Correlation functions for different colliding systems STAR preliminary C2(Qinv) Qinv (GeV/c) Different colliding systems studied at RHIC First opportunity to directly compare AA, pp, (&pA) Wayne State University 22 Nov 05

  7. p1 q p2 Disintegration timescale Relative momentum between pions is a vector  can extract 3D shape information Rlong – along beam direction Rout – along “line of sight”  increases with emission timescale Rside –  “line of sight” Rout Rside Wayne State University 22 Nov 05

  8. Disintegration timescale - expectation 3D 1-fluid Hydrodynamics Rischke & Gyulassy, NPA 608, 479 (1996) with transition with transition “” “” • Long-standing favorite signature of QGP: • increase in , ROUT/RSIDE due to deconfinement  confinement transition • expected to “turn on” as QGP energy threshold is reached Wayne State University 22 Nov 05

  9. A.D. Chacon et al, Phys. Rev. C43 2670 (1991) G. Alexander, Rep. Prog. Phys. 66 481 (2003) AGS/SPS/RHIC HBT papers (expt) Heinz/Jacak Wiedemann/Heinz Csorgo 20 R = 1.2 (fm)•A1/3 Tomasik/Wiedemann Boal/Jennings/Gelbke 15 10 5 ‘85 ‘90 ‘95 ‘00 ‘05 Two decades of systematics “R = 5 fm” • Pion HBT @ Bevalac: “largely confirming nuclear dimensions” • Since 90’s: increasingly detailed understanding and study w/ high stats Wayne State University 22 Nov 05

  10. mass |b| pT (√SNN, b, Npart, A, B, mT, y, ,PID) • Vary signal () • constrain multi-dimensional models • requires flexible detectors, broad approach • Vary colliding system • does physics change? • requires dedicated program • Vary kinematic variables • dynamics and different regimes • requires large acceptance • Vary particle type • consistent picture? • unique probe of dynamical structure • requires good particle identification & acceptance Wayne State University 22 Nov 05

  11. PHOBOS BRAHMS RHIC PHENIX STAR AGS TANDEMS Also: p+p @ 62.4 & 200 GeV Gunther Roland, QM05 Possibilities in a dedicated program: 5 years @RHIC 1 km v = 0.99995c = 186,000 miles/sec Wayne State University 22 Nov 05

  12. Also: p+p @ 62.4 & 200 GeV Gunther Roland, QM05 Possibilities in a dedicated program: 5 years @RHIC Wayne State University 22 Nov 05

  13. Repeating most basic sanity check at relativistic energies... Forget homogeneity regions or fancy stuff. Do femtoscopic length scales increase when they “should?” p-p correlations * big bump  small source • Also • SPS [NA44(‘99),NA49(‘00)] • RHIC [STAR(‘05)] E877 PRC60 054905 (1999) Wayne State University 22 Nov 05

  14. Au+Au sNN =200 GeV Varying initial “source size” Fixed b : vary A (& B!) Fixed A+B : vary b b Likely scaling variable: Npart PHENIX, PRL 2004 R(√SNN, b, Npart, A, B, mT, y, , PID) • Generalize A1/3Npart1/3 • not bad @ RHIC! • connection w/ init. size? Wayne State University 22 Nov 05

  15. PHOBOS R(√SNN, b, Npart, A, B, mT, y, , PID) • Generalize A1/3Npart1/3 • not bad @ RHIC! • connection w/ init. size? • Heavy and light data from AGS, SPS, RHIC • ~s-ordering in “geometrical” Rlong, Rside • Mult ~ K(s)*Npart • source of residual s dep? • ...Yes! common scaling • final state drives radii, not init. geometry • (breaks down s < 5 GeV) NB: not constant density LPSW nucl-ex/0505014 Wayne State University 22 Nov 05

  16. H. Caines (STAR) QM05 Compiled by A. Wetzler (2005) H. Caines (STAR) QM05 NA57 (open) STAR (filled) NA57 (open) STAR (filled) S. Manly (PHOBOS) QM05 Tounsi, Mischke, Redlich NPA715 565 (2003) We are not alone... Entropy determines “everything” at bulk level (soft sector) ? NB: scaling violated s < 4 GeV (as with femtoscopy) Wayne State University 22 Nov 05

  17. Vf N ~ FO volume x-section: CERES, PRL 90 (2003) 022301 m.f.p Refinement: chemical effects • different behaviour below/above AGS • violates “universal” scaling • baryon  meson dominance • neglect time/dynamics: gross F.O. geometry appears determined by • chemistry • “universal” mean free path ~ 1 fm(!?) Wayne State University 22 Nov 05

  18. c.f. Chajecki - lighter systems Messages from systematics • AB, |b|, Npart systematics • sanity check on overall size dependence  • final state multiplicity/chemistry determines rough geometry... ...and that geometry is ~2x initial size collective/flow-like expansion?  probe anisotropically! Wayne State University 22 Nov 05

  19. ? in-plane-extended out-of-plane-extended R(√SNN, b, Npart, A, B, mT, y, ,PID) 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 Wayne State University 22 Nov 05

  20. small RS big RS R(√SNN, b, Npart, A, B, mT, y,,PID) • observe the source from all angles with respect to RP • expect oscillations in HBT radii Wayne State University 22 Nov 05

  21. side side out out R(√SNN, b, Npart, A, B, mT, y,,PID) • observe the source from all angles with respect to RP • expect oscillations in HBT radii (including “new” cross-terms) R2out-side<0 when pair=135º Wayne State University 22 Nov 05

  22. STAR, PRL93 012301 (2004) Measured final source* shape R(√SNN, b, Npart, A, B, mT, y,,PID) R2out-side<0 when pair=135º ever see that symmetry at ycm ? * model-dependent, but see Retiere & MAL PRC70 044907 2004 Wayne State University 22 Nov 05

  23. STAR, PRL93 012301 (2004) central collisions mid-central collisions peripheral collisions Measured final source* shape R(√SNN, b, Npart, A, B, mT, y,,PID) Expected evolution: ? * model-dependent, but see Retiere & MAL PRC70 044907 2004 Wayne State University 22 Nov 05

  24. STAR PRL93 012301 (2004) initial= final c.f. Chajecki - lighter systems Evolution of size and shape - “the rule of two” R(√SNN, b, Npart, A, B, mT, y, ,PID) ~ 1/2 shape reduction ~ x2 size increase Initial size/shape estimated by Glauber calculation Final config according to Retiere & MAL PRC70 044907 2004 Wayne State University 22 Nov 05

  25. AGS: FO  init RHIC: FO < init (approximately same centrality) sNN (GeV) is relation b/t final and  near quantitatively sensible? “Anisotropic sanity check” • non-trivial excitation function • does it make sense? Is it related to bulk dynamics? • YES Wayne State University 22 Nov 05

  26. “radial flow” P. Kolb, nucl-th/0306081 A simple estimate – 0 from init and final • BW → X, Y @ F.O. (X > Y) • hydro: flow velocity grows ~ t • From RL(mT): 0 ~ 9 fm/c • consistent picture • Longer or shorter evolution times • inconsistent • toy estimate: 0 ~ 0(BW)~ 9 fm/c • too short to account for expansion?? • Need a real model comparison→ asHBT workable “evolutionary clock” constraint for models MAL ISMD03 Wayne State University 22 Nov 05

  27. inconsistent with boost-invariance consistent with boost-invariance PHOBOS nucl-ex/0410022 briefly:R(√SNN, b, Npart, A, B, mT, y, , PID) rapidity of emitting source rapidity of emitted particle ? meaning ? another “universal” behaviour Wayne State University 22 Nov 05

  28. Hirano ‘02 Heinz & Kolb, hep-ph/0204061 N() common plots Wayne State University 22 Nov 05

  29. R(√SNN, b, Npart, A, B, mT,y,, PID) hydro cascades LPSW Ann. Rev. Nucl. Part. Sci 2005 • Cascades more successful than hydro • different EoS • different assumptions • different freezeout • different methods of getting radii!! qualitative pT dependence generic Wayne State University 22 Nov 05

  30. R(√SNN, b, Npart, A, B, mT,y,, PID) Why do the radii fall with increasing mT ?? Wayne State University 22 Nov 05

  31. R(√SNN, b, Npart, A, B, mT,y,, PID) Why do the radii fall with increasing mT ?? It’s collective flow !! (we assume...) Directgeometrical/dynamicalevidence for bulk behaviour Amount of flow consistent with p-space Wayne State University 22 Nov 05

  32. Flow-dominated model w/ “hand-tuned” short timescales • Blast-wave model (latest in long series) reproducesp- and x-space • Also non-id, asHBT... • quantitatively consistent soft-sector description F. Retiere, QM04 F. Retiere & MAL, PRC 70 (2004) Wayne State University 22 Nov 05

  33. LPSW(05) - DATA in color-- experimentalist’s plot what agreement!! (what agreement?) Strong flow confirmed by all expts... R(√SNN, b, Npart, A, B, mT,y,, PID) Wayne State University 22 Nov 05

  34. Strong flow confirmed by all expts... R(√SNN, b, Npart, A, B, mT,y,, PID) Central (~10%) AuAu (PbPb) collisions at y~0 Wayne State University 22 Nov 05

  35. Also: strong flow --> “universal” ~mT scaling R(√SNN,b, Npart, A, B, mT,y,,PID) R(√SNN, b, Npart, A, B, mT,y,,PID) Is ubiquitous beauty still beautiful? Wayne State University 22 Nov 05

  36. Gong et al, PRC43 1804 (1991) PRL70, 3709 (1993) 45Sc(36Ar,pp)X E=80 AMeV sNN=1.92 GeV ; sNN-2mN=0.041 GeV Is “famous” systematic everywhere? p-p correlations flow might be relevant... Wayne State University 22 Nov 05

  37. R (fm) “out” vs “side” PRC49, 2788 (1994) 0 1000 2000 3000 4000  (fm/c) PRC49, 2788 (1994) Who says femtoscopy can’t measure long lifetimes? Gong et al, PRC43 1804 (1991) Is “famous” systematic everywhere? p-p correlations 129Xe(27Al,pp)X E=31 AMeV sNN=1.891 GeV ; sNN-2mN=0.0157 GeV E*/AC.N.= 2.6 MeV Wayne State University 22 Nov 05

  38. STAR prelim. Ignore low-s (S.O.P.) use reference of R(√SNN, b, Npart, A, B, mT,y,, PID) • Au+Au reaction zone: x2 expansion • Preliminary Cu+Cu, d+Au, p+p:smooth interpolation • central Cu+Cu = periph Au+Au • Little expansion for small system • shorter timescales? • less bulk collectivity...? N.B : dN/dy scaling preserved Wayne State University 22 Nov 05

  39. 200 GeV Au+Au 200 GeV p+p STAR PRC71 044906 (2005) STAR preliminary mT (GeV) mT (GeV) Ignore low-s (S.O.P.) use reference of R(√SNN, b, Npart, A, B, mT,y,, PID) • famous systematic independent of |b| • observed also for lightest system (p+p) Wayne State University 22 Nov 05

  40. Z0 decay @ LEP R Z(fm) DELPHI  200 GeV p+p  R (fm) K p  STAR preliminary mT (GeV) mT (GeV) m, mT (GeV) hep-ph/0108194 • p+p and A+A measured in same • experiment • great opportunity to compare physics • what causes pT-dep in p+p? • same cause as in A+A? 1. Heisenberg uncertainty? • e.g. G. Alexander • “plausible” in z-direction • unlikely in transvrse 2. String fragmentation? (Lund) • pT dependence maybe (??) • mass dependence probably no [Andersson, Moriond 2000] 3. Resonance effects? • e.g. Wiedemann & Heinz ‘97 • maybe, but presumably significantly different effect than for Au+Au • under investigation Wayne State University 22 Nov 05

  41. Z0 decay @ LEP R Z(fm) flow not expected in such a small system as p+p e.g. Shuryak:hep-ph/0405066 • Csorgoet al.: Buda-Lund treatment of p+p collision as bulk system(w/ temperature gradients)hep-ph/0406042  4. Bulk system („hydro”) in pp? DELPHI K 1/(2pmT)d2n/(dmTdy) p  200 GeV p+p  mT-m (GeV) R (fm) • d+Au : Rlong doesn’t change with centrality RSIDE RLONG ROUT K p  STAR preliminary mT (GeV) mT (GeV) mT (GeV) m, mT (GeV) hep-ph/0108194 • p+p and A+A measured in same • experiment • great opportunity to compare physics • what causes pT-dep in p+p? • same cause as in A+A? 1. Heisenberg uncertainty? 2. String fragmentation? (Lund) 3. Resonance effects? Wayne State University 22 Nov 05

  42. Surprising („puzzling”) scaling Ratio of (AuAu, CuCu, dAu) HBT radii by pp • first-ever pp/AA comparison yields a surprise! • similar underlying physics? HBT radii scale with pp Scary coincidence or something deeper? pp, dAu, CuCu - STAR preliminary Wayne State University 22 Nov 05

  43. What the “coincidence” does NOT mean • pp appears to be blasting system (?!) • AA ≠(pp) • would mean local x-p correlations(giving identical p-space...) • More like pp = “little AA” !! Wayne State University 22 Nov 05

  44. Don’t forget where the “radii” come from... long-range correlations for small systems Wayne State University 22 Nov 05

  45. STAR PRC71 044906 (2005) • Harmonic Decomposition Analysis • exploits full symmetry of q-space • explicit isolation of femtoscopic(& non-femtoscopic) effects • full 3D CF seen clearly in few plots • acceptance-robust (*) • Cartesian HDDanielewicz & Pratt nucl-th/0501003 • Spherical HDChajecki,Gutierrez,MAL,Lopez nucl-ex/0505009 out “Gaussian fit” (remember: not Gaussian CF) side long Michael Lisa: “Salient geometrical...” bullet just means: if I want to know “Rlong” or so, I *mostly* just look at width of long projection, but there are also acceptance effects 1D projections: a limited view • Usual 1D out-side-long “Cartesian projections” • limited view of data • ~set of zero measure of 3D CF • Fit-violating trends may be hidden • Salient geometrical effects non-trivially convoluted • acceptance-dependent (unlike 3D CF) Wayne State University 22 Nov 05

  46. QLONG Q  QOUT  QSIDE Spherical harmonic decomposition of CF • Cartesian-space (out-side-long) naturally encodes physics, but is “inefficient” representation • Harmonic Moments -- 1::1 connection to source geometry [Danielewicz,Pratt: nucl-th/0501003] • ~immune to acceptance • full information content at a glance[thanks to symmetries] Wayne State University 22 Nov 05 Chajecki., Gutierrez, MAL, Lopez-Noriega, nucl-ex/0505009

  47. RL < RT ~acceptance free RL > RT RO < RS Simple, Gaussian source calculations RO > RS “Mental calibration” - a Gaussian CF Chajecki., Gutierrez, MAL, Lopez-Noriega, nucl-ex/0505009 • Full 3D structure • (high-L (fine structure) coefficients drop off) • Different geometrical aspects separate & use “all” relevant information in the CF • AL≠0 vanishes in non-femtoscopic region Wayne State University 22 Nov 05

  48. SH Moments C(Qout) A00 A20 C(Qside) Chajecki., Gutierrez, MALLopez-Noriega, nucl-ex/0505009 C(Qlong) A22 STAR preliminary STAR Central Au+Au -- Spherical HD 1D o-s-l projections Wayne State University 22 Nov 05

  49. STAR preliminary d+Au peripheral collisions ad hoc, but try it... Gaussian fit Baseline problems with smallest systems Wayne State University 22 Nov 05

  50. STAR preliminary Spherical harmonics d+Au peripheral collisions L =2 M=0 data NA22 fit L =1 M=0 NA22 fit L =1 M=1 L =2 M=2 Try NA22 empirical form Wayne State University 22 Nov 05

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