Quarkonium as Probe of Hot QCD Medium. Ágnes Mócsy

Transcription

1 Quarkonium as Probe of Hot QCD Medium Ágnes Mócsy

2 Quarkonium as Probe of Hot QCD Medium Ágnes Mócsy in collaboration with Peter Petreczky (BNL), Chuan Miao (Uni Mainz)

3 QCD Expectations - Temperature effects in deconfined medium: screening, Landau damping,... - In-medium properties encoded in quarkonium spectral functions Dissolution ( melting ) seen as progressive broadening and disappearance of bound-state peaks T=0 T>0 T>Td - Theory predicts the J/ψ disappears in the plasma J/ψ suppression proposed signal of deconfined QGP Matsui, Satz PLB

4 What We Know from Lattice Deconfinement Color screening T=0 F1(r,T)[GeV] Cheng et al (RBC-Bielefeld) PRD 77, (2008) r[fm] - Rapid rise of the energy density: liberation of new degrees of freedom - Strong screening of static Q-Qbar free energy - at shorter distances with increasing T

5 What We Know from Lattice Deconfinement Color screening T=0 F1(r,T)[GeV] J/ψ Y Cheng et al (RBC-Bielefeld) PRD 77, (2008) r[fm] - Rapid rise of the energy density: liberation of new degrees of freedom - Strong screening of static Q-Qbar free energy - at shorter distances with increasing T rscr < rj/ψ melting of the J/ψ

6 Experimental RAA - J/ψ nuclear modification factor: yield in AA collisions relative to yield in pp (where no QGP formation expected) scaled with number of binary NN collisions - J/ψ-suppression pattern observed at SPS and RHIC and LHC 5

7 Experimental RAA The J/ψ story: Two decades worth of data Modest theory advancement Lots of ad-hoc phenomenological modeling It is difficult to unambiguously interpret - we are still not there 6

8 Experimental RAA The J/ψ story: Two decades worth of data Modest theory advancement Lots of ad-hoc phenomenological modeling It is difficult to unambiguously interpret - we are still not there The Υ story: just started! 7

9 What s the Physics Behind? But is the J/ψ RAA a signal for deconfinement and screening?! To answer this question we need to know: - How the properties of J/ψ change in a deconfined medium Determine the spectral function - Relate an equilibrium spectral function to RAA Through real-time dynamics - Identify what physics might contribute to RAA for example: Suppression is seen in pa, da data as well (where no QGP formation expected) Cold nuclear matter effects - could be relevant to AA 8

10 Determine the Spectral Function 9

11 Theory Progress - Lattice QCD, potential models, effective field theories (EFT) - Recently: Spectral functions are calculated Cabrera, Rapp, Mócsy, Petreczky, Alberico, Beraudo, Laine et al Kaczmarek et al, Morita et al,... - Potential model assumes: most medium effects on quarkonium described by a T-dependent potential. True when Ebin is the smallest scale. Internal energy U or free energy F or combination of these 10

12 Theory Progress - Lattice QCD, potential models, effective field theories (EFT) - Recently: Spectral functions are calculated Cabrera, Rapp, Mócsy, Petreczky, Alberico, Beraudo, Laine et al Kaczmarek et al, Morita et al,... - Potential model assumes: most medium effects on quarkonium described by a T-dependent potential. True when Ebin is the smallest scale. Internal energy U or free energy F or combination of these Which one of these is the correct potential has become an irrelevant question! Thermodynamic quantities calculated on the lattice related to potential only in very special cases (ex. LO weak coupling) 11

13 Theory Progress - Recently: Potential model (can be placed on more solid grounds) appears as the tree-level approximation of the EFT and can be systematically improved Isotrop: Laine et al, Brambilla et al, Blaizot et al, Escobado, Soto,... Anisotrop: Strickland et al, Philipsen et al, 12

14 Theory Progress - Recently: Potential model (can be placed on more solid grounds) appears as the tree-level approximation of the EFT and can be systematically improved Isotrop: Laine et al, Brambilla et al, Blaizot et al, Escobado, Soto,... Anisotrop: Strickland et al, Philipsen et al, complex potential T-effects: screening, Landau-damping, singlet-octet transition... 12

15 Theory Progress - Recently: Potential model (can be placed on more solid grounds) appears as the tree-level approximation of the EFT and can be systematically improved Isotrop: Laine et al, Brambilla et al, Blaizot et al, Escobado, Soto,... Anisotrop: Strickland et al, Philipsen et al, complex potential T-effects: screening, Landau-damping, singlet-octet transition... bonus: the applicability of potential model approach is apparent 12

16 Theory Progress - Recently: Potential model (can be placed on more solid grounds) appears as the tree-level approximation of the EFT and can be systematically improved Isotrop: Laine et al, Brambilla et al, Blaizot et al, Escobado, Soto,... Anisotrop: Strickland et al, Philipsen et al, complex potential T-effects: screening, Landau-damping, singlet-octet transition... bonus: the applicability of potential model approach is apparent drawback: weak coupling assumption. how to include perturbative effects? 12

17 The Complex Potential Thermal contributions come from Re ( binding energy) and Im ( width) part Constrain ReV s (r) by lattice QCD data on the singlet free energy Maximal value (upper bound) Take ImV s (r) from HTL resummed pqcd calculations Minimal value (lower bound) Mócsy, Petreczky, PRL 99 (07) Burnier, Laine, Vepsalainen JHEP 0801 (08) 043 Beraudo, arxiv:

18 1.2T c 1.2T c T=0 potential Internal energy- upper limit TS Free energy - lower limit Mocsy, Petreczky, PRD 77 (2008) 14

19 1.2T c 1.2T c T=0 potential Most confining potential Internal energy- upper limit TS Free energy - lower limit Mocsy, Petreczky, PRD 77 (2008) 14

20 The Complex Potential Thermal contributions come from Re ( binding energy) and Im ( width) part Constrain ReV s (r) by lattice QCD data on the singlet free energy Maximal value (upper bound) Take ImV s (r) from HTL resummed pqcd calculations Minimal value (lower bound) Mócsy, Petreczky, PRL 99 (07) Burnier, Laine, Vepsalainen JHEP 0801 (08) 043 Beraudo, arxiv:

21 The Complex Potential Thermal contributions come from Re ( binding energy) and Im ( width) part Constrain ReV s (r) by lattice QCD data on the singlet free energy Maximal value (upper bound) Take ImV s (r) from HTL resummed pqcd calculations Minimal value (lower bound) Mócsy, Petreczky, PRL 99 (07) Burnier, Laine, Vepsalainen JHEP 0801 (08) 043 Beraudo, arxiv:

22 The Complex Potential Thermal contributions come from Re ( binding energy) and Im ( width) part Constrain ReV s (r) by lattice QCD data on the singlet free energy Maximal value (upper bound) Take ImV s (r) from HTL resummed pqcd calculations Minimal value (lower bound) Mócsy, Petreczky, PRL 99 (07) Burnier, Laine, Vepsalainen JHEP 0801 (08) 043 Beraudo, arxiv: Study the effect of color screening and of dissipation on the quarkonium spectral functions. 15

23 Charmonium Spectral Function Take the upper limit for the real part of the potential allowed by lattice calculations Calculated in full QCD "(!)/! 2 T=0 245MeV 326MeV 449MeV Mocsy, Petreczky, PRL 2007, PRD 2008, residual correlations Im V s (r) = ![GeV] - 1S peak with reduced binding energy - residual c-cbar correlations persist 16

24 Charmonium Spectral Function Calculated in full QCD Take the upper limit for the real part of the potential allowed by lattice calculations "(!)/! 2 T=0 245MeV 326MeV 449MeV Mocsy, Petreczky, PRL 2007, PRD 2008, residual correlations Im V s (r) = ![GeV] - 1S peak with reduced binding energy - residual c-cbar correlations persist Take the perturbative imaginary part of the potential and the code from Burnier, Laine, Vepsalainen JHEP 0801 (08) 043 "(!)/! 2 T=0 245MeV 326MeV 449MeV Petreczky, Miao, Mocsy, Nucl Phys A 2011 Im V s (r) ![GeV] - dramatic changes with Im part, peaks strongly broaden 16

25 Charmonium Spectral Function Calculated in full QCD Take the upper limit for the real part of the potential allowed by lattice calculations "(!)/! 2 T=0 245MeV 326MeV 449MeV Mocsy, Petreczky, PRL 2007, PRD 2008, residual correlations Im V s (r) = ![GeV] - 1S peak with reduced binding energy - residual c-cbar correlations persist Take the perturbative imaginary part of the potential and the code from Burnier, Laine, Vepsalainen JHEP 0801 (08) 043 "(!)/! 2 T=0 245MeV 326MeV 449MeV Petreczky, Miao, Mocsy, Nucl Phys A 2011 Im V s (r) ![GeV] - dramatic changes with Im part, peaks strongly broaden No charmonium state could survive for T > 240 MeV 16

26 Bottomonium Spectral Function Calculated in full QCD Take the upper limit for the real part of the potential allowed by lattice calculations Mocsy, Petreczky, PRL 2007, PRD 2008 Take the perturbative imaginary part of the potential and the code from Burnier, Laine, Vepsalainen JHEP 0801 (08) 043 Petreczky, Miao, Mocsy, Nucl Phys A S 2S 3S 1S 2S 3S Im V s (r) =0 Im V s (r) 0-1S peak and remnant of 2S state there - Binding energies reduced - Threshold enhancement - Changing Re part has little effect - Dramatic changes with Im part peaks significantly broaden 17

27 Bottomonium Spectral Function Calculated in full QCD Take the upper limit for the real part of the potential allowed by lattice calculations Mocsy, Petreczky, PRL 2007, PRD 2008 Take the perturbative imaginary part of the potential and the code from Burnier, Laine, Vepsalainen JHEP 0801 (08) 043 Petreczky, Miao, Mocsy, Nucl Phys A S 2S 3S 1S 2S 3S Im V s (r) =0 Im V s (r) 0-1S peak and remnant of 2S state there - Binding energies reduced - Threshold enhancement - Changing Re part has little effect - Dramatic changes with Im part peaks significantly broaden No bottomonium state could survive for T > 450 MeV 17

28 Melting Temperatures Note - Ebin would be smaller with other potentials -- lower melting temperatures - Charmonium sensitive to Re V Bottomonium sensitive to Im V Could be different mechanism behind melting J/ψ and Y - Quantitative estimates of peak disappearance Thermometer of upper limits Tdiss T/T C 1/ r 2 ϒ(1S) χ b (1P) J/ψ(1S) χ c (1P) Note: At finite temperature Ebinding=0 is an overkill for dissociation! 18

29 Lattice says so... - Ugly rumor : Lattice tells J/ψ survives to 2Tc There is no evidence for that. - Neither the unchanged Euclidean correlator ratios, nor the extracted spectral functions suggest charmonium survival. 19

30 Lattice says so... - Correlation function of mesonic currents in Euclidean time are calculated G τ, r p,t ( ) = d 3 xe ir p x r j H ( ) ( τ, x r ) j + H 0, 0 r - Correlators ratios studied ( ) = σ ω,t G τ,t G rec τ,t ( ) = σ ω,t = 0 ( )K( τ,ω,t)dω ( )K( τ,ω,t)dω - We now understand that changes come from zero modes - Correlator ratios do not change in all channels - Potential model agree with lattice Correlator ratios not sensitive to spectral function changes. 20

31 Charmonium Spectral Function Extracted in quenched QCD Extracted from correlation function of mesonic currents in Euclidean time G( τ,t) = σ( ω,t)k( τ,ω,t)dω correlator directly calculated spectral function extracted not directly calculated G τ,t O (10) data but O (100) degrees of freedom to reconstruct MEM ( ) σ ω,t ( )K maximizes the conditional probability of having the spf given the data and some prior knowledge Umeda et al, EPJ C39S1 (05) 9, Asakawa, Hatsuda,PRL 92 (2004) 01200, Datta et al,prd 69 (04) ,Jakovac et al PRD 2007,... Shortcomings: limited # of data points limited extent in tau default model dependence large 21

32 Charmonium Spectral Function Extracted in quenched QCD Jakovac et al PRD

33 Charmonium Spectral Function Extracted in quenched QCD Jakovac et al PRD 2007 Mocsy, Petreczky, PRD 2008 σ(ω)/ω 2 ω[gev 22

34 Charmonium Spectral Function Extracted in quenched QCD Jakovac et al PRD 2007 Mocsy, Petreczky, PRD 2008 σ(ω)/ω 2 ω[gev Peak (previously regarded as bound state) consistent with threshold enhancement 22

35 Charmonium Spectral Function Extracted in quenched QCD Jakovac et al PRD 2007 prior: perturbative continuum spf (no lattice effects) prior: from T=0 data at high energies peak - no peak?! Strong default model dependence 23

36 Charmonium Spectral Function Extracted in quenched QCD Jakovac et al PRD 2007 Comparing low resolution confined phase (blue) to low resolution deconfined phase (red) and getting an agreement does not imply the agreement will hold at high resolution 24

37 agreement in low resolution does not imply agreement at high resolution 25

38 agreement in low resolution does not imply agreement at high resolution 26

39 agreement in low resolution does not imply agreement at high resolution 27

40 agreement in low resolution does not imply agreement at high resolution 28

41 Charmonium Spectral Function Extracted in quenched QCD Jakovac et al PRD 2007 (extracted) Lattice spectral functions do not suggest Jpsi survival well into the deconfined medium 29

42 Comparison to Other Works Most recent extracted charmonium spectral functions Ding, Kaczmarek, Karsch, Satz 2010 Talk by H-T Ding (Bielefeld) at BNL in June 2011 prior: from T=0 data at high energies Our analysis suggests that J/ψ is melted already by 1.46 Tc 30

43 Comparison to Other Works Charmonium screening in quark gluon plasma dynamical lattice QCD simulations Screening mass C(z) ~ exp[ Mz ] inverse screening length of charmonium in the medium Talk by Swagato Mukherjee (BNL) at BNL in June 2011 Unlike temporal correlators, spatial correlators can be studied at arbitrary large distances freely propagating c & cbar in the medium charmonium does not feel T 31

44 Comparison to Other Works Charmonium screening in quark gluon plasma dynamical lattice QCD simulations Screening mass C(z) ~ exp[ Mz ] inverse screening length of charmonium in the medium Talk by Swagato Mukherjee (BNL) at BNL in June 2011 Unlike temporal correlators, spatial correlators can be studied at arbitrary large distances freely propagating c & cbar in the medium charmonium does not feel T In-medium charmonia differs from vacuum for T ~ 1.2Tc 31

45 Comparison to Other Works Compared to lattice: Sum rule approach to quarkonium at finite temperature P. Gubler and M. Oka, Prog. Theor. Phys. 124, 995 (2010). P. Gubler, K. Morita and M. Oka, arxiv: [hep-ph]. Talk by Philipp Gubler (TokyoTech) at BNL in June 2011 No reduction of data points, allowing a direct comparison of T=0 and T 0 spectral functions. 32

46 Comparison to Other Works Compared to lattice: Sum rule approach to quarkonium at finite temperature P. Gubler and M. Oka, Prog. Theor. Phys. 124, 995 (2010). P. Gubler, K. Morita and M. Oka, arxiv: [hep-ph]. Talk by Philipp Gubler (TokyoTech) at BNL in June 2011 No reduction of data points, allowing a direct comparison of T=0 and T 0 spectral functions. 32

47 Comparison to Other Works Compared to lattice: Sum rule approach to quarkonium at finite temperature P. Gubler and M. Oka, Prog. Theor. Phys. 124, 995 (2010). P. Gubler, K. Morita and M. Oka, arxiv: [hep-ph]. Talk by Philipp Gubler (TokyoTech) at BNL in June 2011 No reduction of data points, allowing a direct comparison of T=0 and T 0 spectral functions. 32

48 Comparison to Other Works Compared to lattice: Sum rule approach to quarkonium at finite temperature P. Gubler and M. Oka, Prog. Theor. Phys. 124, 995 (2010). P. Gubler, K. Morita and M. Oka, arxiv: [hep-ph]. Talk by Philipp Gubler (TokyoTech) at BNL in June 2011 No reduction of data points, allowing a direct comparison of T=0 and T 0 spectral functions. 32

49 Comparison to Other Works Compared to lattice: Sum rule approach to quarkonium at finite temperature P. Gubler and M. Oka, Prog. Theor. Phys. 124, 995 (2010). P. Gubler, K. Morita and M. Oka, arxiv: [hep-ph]. Talk by Philipp Gubler (TokyoTech) at BNL in June 2011 No reduction of data points, allowing a direct comparison of T=0 and T 0 spectral functions. Both η c and J/ψ melt between T ~ 1.0 T C and T ~ 1.1 T C 32

50 Melting Temperatures Tc used in quarkonium studies by everyone MEM, Cabrera, Rapp, Zhao, Mocsy, Petreczky, Young, Shuryak,... Tc = 270MeV, 204MeV, 196MeV, 190MeV,... T/T C 1/ r 2 ϒ(1S) χ b (1P) J/ψ(1S) χ c (1P) 33

51 Melting Temperatures Tc used in quarkonium studies by everyone MEM, Cabrera, Rapp, Zhao, Mocsy, Petreczky, Young, Shuryak,... Tc = 270MeV, 204MeV, 196MeV, 190MeV,... T/T C 1/ r 2 ϒ(1S) χ b (1P) J/ψ(1S) χ c (1P) - Be aware of the meaning of Tc! In pure gauge theory Tc = 270 MeV Boyd et al 1996 In full QCD there is Tchiral 157 MeV and Tonset of screening MeV Budapest-Wuppertal 2010, HotQCD 2011 Bazavov, Petreczky,

52 Chiral vs Deconfinement defining transition temperature: peak of chiral susceptibility Everyone agrees 34

53 Chiral vs Deconfinement Deconfinement: - liberation of many degrees of freedom, which can be understood as a transition from hadronic degrees of freedom to partonic ones - the onset of screening Cheng et al (RBC-Bielefeld) PRD 77, (2008) pion gas: 3 free quark-gluon gas: ~ 8x2 + 3x2x2x3 = 52 dof? ( ) MeV T > 200MeV Most relevant for quarkonium physics at finite temperature Debye screening, Landau damping - are effects from deconfined quarks and gluons 35

54 Chiral vs Deconfinement Deconfinement: - liberation of many degrees of freedom, which can be understood as a transition from hadronic degrees of freedom to partonic ones - the onset of screening Partonic screening becomes relevant at about ~1.3Tc, where Tc is chiral transition So we are back to T > 200MeV region It is most relevant for quarkonium Bazavov and P.P., arxiv: , arxiv: , arxiv: , Söldner, arxiv:

55 Melting Temperatures Tc used in quarkonium studies by everyone MEM, Cabrera, Rapp, Zhao, Mocsy, Petreczky, Young, Shuryak,... Tc = 270MeV, 204MeV, 196MeV, 190MeV,... T/T C 1/ r 2 ϒ(1S) χ b (1P) J/ψ(1S) χ c (1P) 37

56 Melting Temperatures New Rules: Let s talk about absolute temperatures instead in Tc units 38

57 Melting Temperatures New Rules: Let s talk about absolute temperatures instead in Tc units T/TT C 1/ r MeV ϒ(1S) χ b (1P) MeV MeV J/ψ(1S) χ c (1P) 38

58 From Theory to Data 39

59 Famous Plot How can we relate these? Quarkonium spectral functions in equilibrated plasma Experimental data 40

60 Famous Plot How can we relate these? Quarkonium spectral functions in equilibrated plasma Dynamical models Experimental data 40

61 The Connection - Spectral function calculation no bound states only correlated c-cbar pairs - What is the probability that c-cbar find themselves in proximity at the hadronization time? Zhao, Rapp, van Hees, Fries, Young, Shuryak, Strickland... - Modeling the motion of c-cbar in the evolving fireball illustration by Alex Doig - stochastic force from the heat bath - Input: charm diffusion constant if small enough that attraction between c and cbar may survive - attractive interaction between c-cbar - Input: heavy quark potential - lifetime of the plasma 41

62 The Connection - Comparison to PHENIX data Young, Shuryak, PRC 2010 The 1st microscopic calculation of non-correlated recombination! - total yield - suppression + correlated regeneration - statistical recombination c and cbar originate from different hard processes - Direct J/ψ suppressed, but ~ 50% of correlated c-cbar recombine - Coalescence gives relative small contribution - Quite good agreement with data for small charm diffusion and Tc=190 MeV Note: Tc = Tdeconfinement 42

63 The Connection - Comparison to PHENIX data Young, Shuryak, PRC 2010 The 1st microscopic calculation of non-correlated recombination! - total yield - suppression + correlated regeneration - statistical recombination c and cbar originate from different hard processes - Direct J/ψ suppressed, but ~ 50% of correlated c-cbar recombine - Coalescence gives relative small contribution - Quite good agreement with data for small charm diffusion and Tc=190 MeV Outlook: Petreczky, Mocsy (BNL/Pratt) and Young, Schenke (McGill/BNL) using MUSIC Note: Tc = Tdeconfinement 42

64 The Connection - Comparison to PHENIX data Young, Shuryak, PRC 2010 The 1st microscopic calculation of non-correlated recombination! - total yield - suppression + correlated regeneration - statistical recombination c and cbar originate from different hard processes - Note There are effects not included in this model: initial state effects and absorption in the crossover-hadronic region (CNM effects) - A quantitative comparison with data is difficult 43

65 Isolate Hot Effects from Other Physics 44

66 Can we isolate hot effects? illustration by Alex Doig c and cbar are produced at early times go through the entire evolution end up in hidden (J/ψ) or in open (D) charm 45

67 Can we isolate hot effects? keywords illustration by Alex Doig Cold Nuclear Matter Initial: PDF s modification (shadowing) Final: nuclear absorption Hot Matter screening gluo-dissociation Landau damping threshold enhancement Coalescence (regeneration) coalescence of single c quarks in the plasma Feed-down J/ψ from decays: ψ, χc J/ψ χb, ϒ, ϒ ϒ Hadronic Absorption 46

68 Can we isolate hot effects? new way of organizing illustration by Alex Doig Initial State Deconfined Matter Crossover/Hadronic Region 47

69 Can we isolate hot effects? With CNM effects divided out Anomalous suppression M. Leitch, INT Quarkonium Workshop 2008 This makes sense if - all CNM effects are initial state (shadowing), or - absorption in the crossover region ( mixed phase ) is similar to absorption in nuclear matter 48

70 Can we isolate hot effects? With CNM effects divided out Anomalous suppression M. Leitch, INT Quarkonium Workshop 2008 energy-density - SPS described well with hadronic - reaches into crossover region - RHIC reaches into deconfined region onset of plasma effects (onset of screening) ~ 3.5 GeV/fm 3 ~ 200 MeV 49

71 Other Controls RAA versus pt Great for separating the different contributions Zebo Tang (STAR), QM 2011 STAR CuCu: PRC80, (R) PHENIX: PRL98, At high pt - CNM effects are less important: larger x - Statistical recombination has little effect - A suppression at high pt would indicate suppression of direct J/ψ by the hot medium Silvestre (CMS), QM If no suppression then J/ψ forms outside of (or after) the hot plasma. Formation time! - larger high pt suppression at LHC: can be from smaller x and/or longer lifetime At RHIC: no suppression for J/y at high pt (~5 GeV) in 200GeV Cu+Cu and peripheral Au+Au collisions, but suppression at high pt in central Au At LHC suppression persists to higher pt 50

72 Other Controls ϒpsilon - Y (theoretically) is a much cleaner signal - Initial state effects not very relevant (mb >> Q 2 ) - Absorption is small in the crossover/hadronic region - No recombination: number of b and bbar is negligible (at RHIC) - Easy to calculate spectral function, but dynamical modeling harder - Ground state can survive at RHIC and be suppressed at LHC?! Reed (STAR), QM 2011 Silvestre (CMS), QM

73 Summary The imaginary part of the potential plays a prominent role as a quarkonium dissolution mechanism. Spectral functions determined with complex potential (with effects of color screening and dissipation) Microscopic mechanism behind the melting of Jpsi and Upsilon could be quite different All signs point towards the melting of Jpsi early on in the plasma phase Even the most binding potential allowed by lattice QCD leads 1S charmonium & excited bottomonium melting by T 240 MeV and of the 1S bottomonium states for T 450 MeV Threshold enhancement has phenomenological consequences Dynamical bridging necessary to compare to data - heavy quark diffusion, strength of Q-Qbar correlation, lifetime of deconfined medium High pt - clear hot matter signal?! Y much clearer signal

74 The Sound of the Little Bangs illustration: Alex Doig 53

75 The Sound of the Little Bangs illustration: Alex Doig The Sound of the Little Bangs - Mocsy, Sorensen 2010 Analyzing the Power Spectrum of the Little Bangs - Mocsy, Sorensen 2011 The Rise and Fall of the Ridge in Heavy Ion Collisions - Sorensen, Bolliet, Mocsy, Pandit, Puthri,

76 Ágnes Mócsy with Alex Doig and Paul Sorensen YouTube Video (~ 4 min) : 54

77 Media Attention 55

78 Analogy with the Early Universe illustration: Alex Doig We determine the power-spectrum in heavy-ion collisions. Ágnes Mócsy, Pratt Institute, HARD PROBES 2010, Eilat, Israel

79 Analogy with the Early Universe picture credits NASA/WMAP Science Team CMB temperature map: fluctuations ~10-5 illustration: Alex Doig Quantum fluctuations from the start of the universe that show up as temperaturefluctuations (hotspots) in the CMB. Power spectrum extracted from CMB. Most power is in l~200 corresponding to small distances. We determine the power-spectrum in heavy-ion collisions. Ágnes Mócsy, Pratt Institute, HARD PROBES 2010, Eilat, Israel

80 Analogy with the Early Universe illustration: Alex Doig Quantum fluctuations from the start of the universe that show up as temperaturefluctuations (hotspots) in the CMB. What is the analogy for HIC? We determine the power-spectrum in heavy-ion collisions.

81 Analogy with the Early Universe Au+Au at 200 GeV 0-5% % " ! " Adams, [STAR Collaboration]:J.Phys.G34:S ,

82 Correlation Measurements pt-pt correlations Δρ ρ ref = ρ ρ ref (GeV/c) 2 ρ ref 0-5% % " ! " STAR Collaboration J. Phys. G 32, L37 (2006) illustration: Alex Doig Peak indicates that particles with above average momentum tend to come out together, suggesting they are born out of the same high T lump 60

83 Analogy with the Early Universe Au+Au at 200 GeV 0-5% Power Spectrum % " ! " Adams, [STAR Collaboration]:J.Phys.G34:S , a n [(GeV/c) ] n Mocsy, Sorenen,

84 Temperature Fluctuations in HIC Temperature [MeV]! = 0.6 fm/c Temperature [MeV]! = 4.6 fm/c y [fm] x [fm] 5 y [fm] x [fm] 5 Mocsy, Sorenen, 2010 Au+Au collisions may initially contain hotspots of ~ 1.5 fm and remnants of these persist HIC analog of the CMB map 62

85 Length Scales and Power Spectrum How much of the initial inhomogeneity is transferred to the final state? Spherical harmonic expansion of CMB sum l Higher harmonics probes smaller length-scales. Fourier expansion of HIC n=2 n=3 n=4 n=10 n=15 Efficiency of conversion depends on relation of l mfp to the scale probed at n: <R> average radial position of participants Power spectrum tells the strength transferred into each harmonic n --? get l mfp 63

86 Length Scales and Power Spectrum How much of the initial inhomogeneity is transferred to the final state? Spherical harmonic expansion of CMB sum l Higher harmonics probes smaller length-scales. Fourier expansion of HIC l mfp n=2 n=3 n=4 n=10 n=15 Efficiency of conversion depends on relation of l mfp to the scale probed at n: <R> average radial position of participants Power spectrum tells the strength transferred into each harmonic n --? get l mfp 63

87 Length Scales and Power Spectrum How much of the initial inhomogeneity is transferred to the final state? Spherical harmonic expansion of CMB sum l Higher harmonics probes smaller length-scales. Fourier expansion of HIC l mfp l mfp n=2 n=3 n=4 n=10 n=15 Efficiency of conversion depends on relation of l mfp to the scale probed at n: <R> average radial position of participants Power spectrum tells the strength transferred into each harmonic n --? get l mfp 63

88 Acoustic Horizon another important lengthscale H = distance density perturbations can travel Alex Doig Alex Doig 2010 Horizon means long wavelengths cannot be heard at first. Time-ordering of frequencies 64

89 Acoustic Horizon Alex Doig Alex Doig 2010 Horizon means long wavelengths cannot be heard at first. Time-ordering of frequencies 65

90 Acoustic Horizon Alex Doig Alex Doig 2010 Horizon means long wavelengths cannot be heard at first. Time-ordering of frequencies 66

91 Acoustic Horizon Alex Doig Alex Doig 2010 Horizon means long wavelengths cannot be heard at first. Time-ordering of frequencies 67

92 The Sound of the Little Bang illustration: Alex Doig 68

93 The End 69