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A menu of expectations for femtoscopy * 1.0 at LHC /ALICE

A menu of expectations for femtoscopy * 1.0 at LHC /ALICE. Mike Lisa Ohio State University. * femtoscopy (fem-ta-skö-pee) noun The measurement of spatial scales at the fermi level. Non-trivially related to the “HBT effect” invented to measure stellar scales. Outline.

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A menu of expectations for femtoscopy * 1.0 at LHC /ALICE

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  1. A menu of expectations forfemtoscopy* 1.0 at LHC/ALICE Mike Lisa Ohio State University * femtoscopy (fem-ta-skö-pee) noun The measurement of spatial scales at the fermi level. Non-trivially related to the “HBT effect” invented to measure stellar scales Mike Lisa - ISMD, Berkeley - August 2007

  2. Outline • Brief motivation / review • Model expectations for H.I. collisions [ mostly] • The importance of femtoscopy in p+p collisions • A menu Mike Lisa - ISMD, Berkeley - August 2007

  3. fast energy deposition  plasma  hydro expansion  cooling to original phase • do geometric “postmortem” & infer momentum Mike Lisa - ISMD, Berkeley - August 2007

  4. fast energy deposition  plasma  hydro expansion  cooling to original phase • do geometric “postmortem” & infer momentum Mike Lisa - ISMD, Berkeley - August 2007

  5. measure explosive pattern of the thermalized bulk matter (low-pT) B2B jets? access to bulk properties (EoS) driving dynamics • fast energy deposition  plasma  hydro expansion  cooling to original phase • do geometric “postmortem” & infer momentum Mike Lisa - ISMD, Berkeley - August 2007

  6. collective pT component: m*vT Spectra v2 HBT measure explosive pattern of the thermalized bulk matter (low-pT) hydro expectation (off-center collision) Mike Lisa - ISMD, Berkeley - August 2007

  7. Spectra v2 HBT measure explosive pattern of the thermalized bulk matter (low-pT) “elliptic flow” Mike Lisa - ISMD, Berkeley - August 2007

  8. Spectra v2 HBT measure explosive pattern of the thermalized bulk matter (low-pT) femtoscopy probes x-p substructure Mike Lisa - ISMD, Berkeley - August 2007

  9. hydro cascade ideal fluid dynamics Boltzmann models - collisions between particles 3 talks later At RHIC: Explosive signature sensitive to physics in models What might we expect at LHC? Mike Lisa - ISMD, Berkeley - August 2007

  10. H. Caines (STAR) QM05 NA57 (open) STAR (filled) NA57 (open) STAR (filled) S. Manly (PHOBOS) QM05 MAL,Pratt Soltz,Wiedemann nucl-ex/0505014 E-by-E fluctuation in K/ G. Westfall, WPCF 2007 “All” soft-physics observables at RHIC (& often SPS/AGS)are multiplicity-driven Entropy dominance? Mike Lisa - ISMD, Berkeley - August 2007

  11. 6 5 5.5 TeV 1000 6.4 = RHICx1.6 PHOBOS White Paper: NPA 757, 28 Mike Lisa - ISMD, Berkeley - August 2007

  12. 6.4 = RHICx1.6 6 5 PHOBOS White Paper: NPA 757, 28 5.5 TeV 1000 NNUS*: Multiplicity sets scale: all else fixed • PHOBOS-based extrapolation: • RLHC / RRHIC = (1.6)1/3 = 1.17 * NNUS = Nothing New Under the Sun Mike Lisa - ISMD, Berkeley - August 2007

  13. NNUS*: Multiplicity sets scale: all else fixed • PHOBOS-based extrapolation: • RLHC / RRHIC = (1.6)1/3 = 1.17 • CGC prediction of multiplicity • RLHC / RRHIC = (11/3.6)1/3 = 31/3 = 1.45 Mike Lisa - ISMD, Berkeley - August 2007 Kharzeev, Levin & Nardi NPA747 609 (2005)

  14. NNUS*: Multiplicity sets scale: all else fixed • PHOBOS-based extrapolation: • RLHC / RRHIC = (1.6)1/3 = 1.17 • CGC prediction of multiplicity • RLHC / RRHIC = (11/3.6)1/3 = 31/3 = 1.45 • R <~ 11 fm [low pT pions generate largest separation distribution] Mike Lisa - ISMD, Berkeley - August 2007

  15. STAR PRC71 044906 (2005) Access to low-q -> high R NNUS*: Multiplicity sets scale: all else fixed • PHOBOS-based extrapolation: • RLHC / RRHIC = (1.6)1/3 = 1.17 • CGC prediction of multiplicity • RLHC / RRHIC = (11/3.6)1/3 = 31/3 = 1.45 • R <~ 11 fm • well within experimental reach • Rfit ~ 1/(q2) • q ~ 1 MeV/c • qmin ~ 2 MeV/c Mike Lisa - ISMD, Berkeley - August 2007 ALICE PPR (vol 2): J. Phys G. Part. Nucl. Phys. 32 1295 (2006)

  16. Brown, Soltz, Newby, Kisiel nucl-th/0705.1337 Access to long-range non-Gaussian tail • Generalized imaging* fit probes long-R / low-q • access to resonance tail • small below s ~ 10 GeV • LHC should be ~RHIC • (... and/or “other” tails...) • details beyond gross size PHENIX, PRL 98, 132301 (2007) , * c.f. talks of P. Danielewicz & P. Chung Mike Lisa - ISMD, Berkeley - August 2007

  17. Physics from (Gaussian) scales - dynamic models • Boltzmann models • particle rescattering • thermalization not assumed • typically “hard” EoS • softening must be put in by hand (“string melting” etc) • Hydrodynamic models • thermalization / “perfect fluid” • EoS varied. Typically a “soft point” used Mike Lisa - ISMD, Berkeley - August 2007

  18. dN/d Boltzmann-type models T. Humanic, Int.J.Mod.Phys.E15197(2006) • Humanic/Hadron Rescattering Model • “real” model predicting flow & HBT • (dN/d[LHC] / dN/d[RHIC])1/3 ~ 1.9 Mike Lisa - ISMD, Berkeley - August 2007

  19. dN/dt Rlong (fm) Boltzmann-type models T. Humanic, Int.J.Mod.Phys.E15197(2006) • Humanic/Hadron Rescattering Model • “real” model predicting flow & HBT • (dN/d[LHC] / dN/d[RHIC])1/3 ~ 1.9 • LHC / RHIC = 2 :: (recall Rlong~~ ) • dynamic effect • Rlong[LHC] / Rlong[RHIC] ~ 2 • all are connected?? Mike Lisa - ISMD, Berkeley - August 2007

  20. Boltzmann-type models T. Humanic, Int.J.Mod.Phys.E15197(2006) • Humanic/Hadron Rescattering Model • “real” model predicting flow & HBT • (dN/d[LHC] / dN/d[RHIC])1/3 ~ 1.9 • LHC / RHIC = 2 :: (recall Rlong~~ ) • dynamic effect • Rlong[LHC] / Rlong[RHIC] ~ 2 • all are connected? • RS, RO larger, but not a simple factor Mike Lisa - ISMD, Berkeley - August 2007

  21. Boltzmann-type models T. Humanic, Int.J.Mod.Phys.E15197(2006) • Humanic/Hadron Rescattering Model • “real” model predicting flow & HBT • (dN/d[LHC] / dN/d[RHIC])1/3 ~ 1.9 • LHC / RHIC = 2 :: (recall Rlong~~ ) • dynamic effect • Rlong[LHC] / Rlong[RHIC] ~ 2 • all are connected? • RS, RO larger, but not a simple factor • steeper pT-dep due to more flow? • dynamic effect • Hard EoS rescattering models: dynamic effects superimposed on chemistry • similar for AMPD C.M. Ko; WPCF06 Mike Lisa - ISMD, Berkeley - August 2007

  22. Eskola et al PRC72044904 (2005) initial conditions from pQCD+saturation Hydro predictions I: Scales • Neglecting flow, to cool to C[QGP] :C = 0(C /0)3/4 • Cno flow[RHIC] = 6 fm/c • Cno flow[LHC] = 20 fm/c Mike Lisa - ISMD, Berkeley - August 2007

  23. Eskola et al PRC72044904 (2005) Hydro predictions I: Scales • Neglecting flow, to cool to C[QGP] :C = 0(C /0)3/4 • Cno flow[RHIC] = 6 fm/c • Cno flow[LHC] = 20 fm/c • Much larger flow @LHC • signif. reduction of timescale @ LHC [similar to RHIC] • larger transverse size @ FO Mike Lisa - ISMD, Berkeley - August 2007

  24. Eskola et al PRC72044904 (2005) Hydro predictions I: Scales • Neglecting flow, to cool to C[QGP] :C = 0(C /0)3/4 • Cno flow[RHIC] = 6 fm/c • Cno flow[LHC] = 20 fm/c • Much larger flow @LHC • signif. reduction of timescale @ LHC [similar to RHIC] • larger transverse size @ FO • No HBT prediction per se, but... • RL[LHC] / RL[RHIC] ~ 1.1 ÷ 1.2 • RS[LHC] / RS[RHIC] ~ 1.5 ÷ 2 • (different than HRM) • steeper pT-dependence Mike Lisa - ISMD, Berkeley - August 2007

  25. Eskola et al PRC72044904 (2005) Heinz&Kolb, PLB542 216 (2002) Hydro predictions I: Scales • Neglecting flow, to cool to C[QGP] :C = 0(C /0)3/4 • Cno flow[RHIC] = 6 fm/c • Cno flow[LHC] = 20 fm/c • Much larger flow @LHC • signif. reduction of timescale @ LHC [similar to RHIC] • larger transverse size @ FO • No HBT prediction per se, but... • RL[LHC] / RL[RHIC] ~ 1.1 ÷ 1.2 • RS[LHC] / RS[RHIC] ~ 1.5 ÷ 2 • (different than HRM) • steeper pT-dependence • Consistent w/ independent hydrofor non-central collisions (LHC) Mike Lisa - ISMD, Berkeley - August 2007

  26. STAR 200 GeV PRL93 012301 (‘04) Hydro predictions II: Shapes ALICE PPR (vol 2): J. Phys G. Part. Nucl. Phys. 32 1295 (2006) • easy prediction: importance of -dep measurements will continue @ LHC • RP resolution at least as good as STAR • asHBT • measures source shape at freezeout Mike Lisa - ISMD, Berkeley - August 2007

  27. PLB496 1 (2000) E895 2 GeV STAR 200 GeV O’Hara, et al, Science 298 2179 (2002) PRL93 012301 (‘04) Hydro predictions II: Shapes  • easy prediction: importance of -dep measurements will continue @ LHC • RP resolution at least as good as STAR • asHBT • measures source shape at freezeout • probes timescale & dynamics • non-trivial (& incomplete!) excitation fctn Mike Lisa - ISMD, Berkeley - August 2007

  28. “RHIC” STAR PRL93 012301 (2004) Heinz&Kolb, PLB542 216 (2002) Hydro predictions II: Shapes  • easy prediction: importance of -dep measurements will continue @ LHC • RP resolution at least as good as STAR • asHBT • measures source shape at freezeout • probes timescale & dynamics • non-trivial (& incomplete!) excitation fctn • hydro @ RHIC • misses scale (well-known) • impressive agreement on -dep Mike Lisa - ISMD, Berkeley - August 2007

  29. “RHIC” “IPES” (LHC) Heinz&Kolb, PLB542 216 (2002) Heinz&Kolb, PLB542 216 (2002) Hydro predictions II: Shapes  • easy prediction: importance of -dep measurements will continue @ LHC • RP resolution at least as good as STAR • asHBT • measures source shape at freezeout • probes timescale & dynamics • non-trivial (& incomplete!) excitation fctn • hydro @ RHIC • misses scale (well-known) • impressive agreement on -dep • prediction @ LHC • sign change in shape & oscillations Sign flip in oscillations reflects transition to in-plane geometry (more flow, more time) Mike Lisa - ISMD, Berkeley - August 2007

  30. p+p: A clear reference system? Mike Lisa - ISMD, Berkeley - August 2007

  31. OPAL e+e- -> Z July 2007 CERN-PH-EP/2007-025 e+e- (and p+p, +p...) -- “similar” HBT radii • high-quality/stats data sparse • diversity of methods • corrections • coordinate systems • jet axis in e+e-... • mixing... • physics? Mike Lisa - ISMD, Berkeley - August 2007

  32. i-th particle Initial “disk” of radius r L. Lonnblad - WPCF2007 e+e- (and p+p, +p...) -- “similar” HBT radii • high-quality/stats data sparse • diversity of methods • corrections • coordinate systems • jet axis in e+e-... • mixing... • physics of “x-p” correlations in very small systems? • strings? • jets? • pythia + rescattering? • else? pT signal? Paic and Skowronski J. Phys. G311045 (2005) see also Csorgo & Zajc hep-ph/0412243 (ISMD04) Mike Lisa - ISMD, Berkeley - August 2007 talk by T. Humanic

  33. STAR preliminary mT (GeV) mT (GeV) Caution: femtoscopy in p+p @ STAR Z. Chajecki WPCF05 • p+p and A+A measured in same experiment with same method • great opportunity to compare physics • what causes pT-dependence in p+p? • same cause as in A+A?? Mike Lisa - ISMD, Berkeley - August 2007

  34. Ratio of (AuAu, CuCu, dAu) HBT radii by pp pp, dAu, CuCu - STAR preliminary Surprising („puzzling”) scaling • !! But !! significant issues with nontrivial • interplay non-femtoscopic correlations • (restricted phasespace) • should be less of a problem at LHC • [see talk of T. Humanic] • p+p and A+A measured in same experiment with same method • great opportunity to compare physics • what causes pT-dependence in p+p? • same cause as in A+A? A. Białasz (ISMD): I personally feel that its solution may provide new insight into the hadronization process of QCD HBT radii scale with pp Scary coincidence or something deeper? Mike Lisa - ISMD, Berkeley - August 2007

  35. le menu des espérances au LHC hydro NNUS: naive extrapolation p+p • signif pT dep • R increase w/ mult RL small increase (~30%) [huge flow  rapid cooling  short ] as before (same pT dep etc) but scale by ~17% • R increase w/ mult • other details?? • RO,S : huge flow  • larger increase (~60%) • steeper pT dep 5 as before(same pT dep etc) but scale by ~45% • very large RO in high mult?? shape inversion; oscillation sign flip p+p “=“ A+A ??? large tilt for central region? HRM andAMPT jet RL (50-100%30%increase) [dynamics / chemistry / both ??] • RO,S • smaller increase (~30% 10%) • higher flow  steeper pT dep p p jet entrées boissons plats principaux Mike Lisa - ISMD, Berkeley - August 2007

  36. Mike Lisa - ISMD, Berkeley - August 2007

  37. extract phaseshifts (inversion of K-P paradigm) • p+p in multiplicity classes [esp very low multiplicity] • HBT relative to jets in p+p and A+A • excitation function • - (direct  yield) R(√SNN, b, Npart, A, B, mT, y, ,PID1, PID2) Does lock pattern break? Mike Lisa - ISMD, Berkeley - August 2007

  38. The end (...finally...) Mike Lisa - ISMD, Berkeley - August 2007

  39. ALICE PPR (vol 2): J. Phys G. Part. Nucl. Phys. 32 1295 (2006) Relative momentum resolution • ITS+TPC tracks • 2 MeV/c (-> 100 fm, for scale only...) • del-qside small since azim. angle well-known • qout probes sagitta resolution • heavier particles • less bending -> smaller sagitta -> worse resolution • but due to mT scaling, worse resolution is OK :-) Mike Lisa - ISMD, Berkeley - August 2007

  40. ALICE PPR (vol 2): J. Phys G. Part. Nucl. Phys. 32 1295 (2006) Track merging effects in the TPC • merging -> ~0.3 fm bias in HBT radius determination for 8 fm source • less impt for smaller sources • less impt if Coulomb FSI included (?) • impact on imaging (non-Gaussian shapes) (?) • merging correlated in qo-qs (can mimic “tilted source”) • requiring separation in TPC helps remove effect, but convergence is slow Mike Lisa - ISMD, Berkeley - August 2007

  41. ALICE PPR (vol 2): J. Phys G. Part. Nucl. Phys. 32 1295 (2006) The ITS helps remove merging effects • Ros = 0 as figure of merit • Cutting on ITS separation reduces bias to ~0.1-0.2 fm “similar triangles” : qmin/pT = separationMin/radius Mike Lisa - ISMD, Berkeley - August 2007

  42. ALICE PPR (vol 2): J. Phys G. Part. Nucl. Phys. 32 1295 (2006) method of NA44/E895/STAR/... Momentum resolution correction • “Triple-ratio” correction first (?) used by NA44 • uses single-particle resolution (assumed known) to smear “ideal” CF • rapid convergence Mike Lisa - ISMD, Berkeley - August 2007

  43. ALICE PPR (vol 2): J. Phys G. Part. Nucl. Phys. 32 1295 (2006) HBT radii : “out versus in” • good to ~15 fm Mike Lisa - ISMD, Berkeley - August 2007

  44. ALICE PPR (vol 2): J. Phys G. Part. Nucl. Phys. 32 1295 (2006) Event-by-event femtoscopy in Pb+Pb Mike Lisa - ISMD, Berkeley - August 2007

  45. ALICE PPR (vol 2): J. Phys G. Part. Nucl. Phys. 32 1295 (2006) reactionplane resolution • At least as good as RHIC/STAR Plot from T. Hirano 2005 Mike Lisa - ISMD, Berkeley - August 2007

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