Beijing. Charmed hadron signals of partonic medium. Olena Linnyk

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1 Beijing Charmed hadron signals of partonic medium Olena Linnyk

2 Our goal properties of partonic matter Hadron-string models Experiment QGP models

3 Observables Hadron abundances J/Ψ anomalous suppression at SPS J/Ψ anomalous suppression at RHIC J/Ψ rapidity distribution at RHIC Elliptic flow of D-mesons Elliptic flow of J/Ψ Quenching of charm at RHIC

4 Basic concepts of Hadron-String Dynamics for each particle species i (i = N, R, Y, π, ρ, K, ) the phase-space density f i follows the transport equations t + ( ) H ( H ) f ( r, p,t) = I (f,f,...,f ) p r r p i coll 1 2 M with the collision terms I coll describing: elastic and inelastic hadronic reactions formation and decay of baryonic and mesonic resonances BB < > B B,, BB < > B B m, mb < > m B, mb < > B string formation and decay (for inclusive production: BB->X, mb->x, X =many particles) Implementation of detailed balance on the level of 1< >2 and 2< >2 reactions (+ 2< >n multi-meson fusion reactions) Off-shell dynamics for short living states No explicit quark and gluon degrees-of-freedom, partons only in the strings

5 Charmonium production in σ πn (s) [nb] σ pn (s) [nb] p+n D+Dbar J/Ψ Ψ / Hard probe->binary scaling! π+n D+Dbar J/Ψ Ψ / all x F all x F s 1/2 [GeV] primary (Baryon+Baryon) secondary (meson+baryon) recreation (D+D < > J/Ψ+meson) dn/dt Au+Au, s 1/2 =200 GeV, central N DD ~16 J/Ψ+m->D+Dbar D+Dbar->J/Ψ+m time [fm/c] at RHIC, recreation of J/Ψ by D-Dbar annihilation is strong!

6 Charmonium interactions with the medium in Default comover absorption scenario: Interactions with nucleons (normal nuclear absorption, as in pa) Absorption on formed mesons (comovers), J/Ψ+m >D+D Recombination by D+Dbar annihilation, D+D >J/Ψ+m Modified comover, i.e. prehadron interaction scenario: additionally, absorption and elastic scattering by prehadrons=mesons and baryons under formation time of τ~0.8 fm/c in their rest frame)

7 Observables Hadron abundances J/Ψ anomalous suppression at SPS J/Ψ anomalous suppression at RHIC J/Ψ rapidity distribution at RHIC Elliptic flow of D-mesons Elliptic flow of J/Ψ Quenching of charm at RHIC

8 Hadron abundances very good description of particle production in pp, pa reactions with unique description of nuclear dynamics from low (~100 MeV) to ultrarelativistic (~20 TeV) energies Au+Au (central) AGS NA49 BRAHMS Multiplicity π + η K + K φ D(c) D(c) ' 99 J/Ψ AGS SPS RHIC Energy [A GeV]

9 J/Ψ anomalous suppression at SPS (σ(j/ψ)/σ(dy)) / (σ(j/ψ)/σ(dy)) Glauber NA60, In+In, 158 A GeV Comover absorption NA50, Pb+Pb, 158 A GeV Comover absorption NA60, In+In, 158 A GeV (2007) N part B µµ (Ψ') σ / B (J/Ψ) σ Ψ' µµ J/Ψ Pb+Pb, 158 A GeV NA NA Comover absorption E T [GeV] Both J/Ψ and Ψ suppression in Pb+Pb and 160 A GeV are consistent with the comover absorption scenario. [OL et al., NPA 786 (2007) 183 ]

10 R AA (J/Ψ) J/Ψ anomalous suppression at RHIC Au+Au, s 1/2 =200 GeV Comover absorption comover scenario y < < y <2.2 B µµ dn(j/ψ)/dy central, 0-20% Au+Au, s 1/2 =200 GeV semi-central, 20-40% PHENIX, y <0.35 PHENIX, 1.2< y < N part Centrality dependence reproduced µµ dn(j/ψ)/dy B µµ semi-peripheral, 40-60% y comover prehadron interactions PHENIX peripheral, 60-90% But: the suppression at mid-y is stronger than at forward y, y unlike data! [OL et al., PRC 76 (2007) ; NPA 807 (2008) 79] y

11 Prehadron interaction scenario 1. early interactions of charmonium (ccbar) and D-mesons with unformed (under formation time t = γ τ F, τ F ~0.8 fm/c) baryons and mesons = prehadrons 2. comover absorption with recombination by D-Dbar annihilation Dissociation cross sections of charmonium by pre-hadrons: = 5.8 mb, σ dis cc pre-baryon σ dis cc pre-meson = 2/3 σ dis cc pre-baryon Elastic cross sections with prehadrons: Charmonium - prehadrons: D-meson - prehadrons: Fitted to PHENIX data σ el cc pre-baryon = 1.9 mb, σ el D pre-baryon = 3.9 mb, σ el cc pre-meson = 2/3 σ el cc pre-baryon σ el D pre-meson = 2/3 σ el cc pre-baryon [For details see: OL et al., arxiv: Int J Mod Phys (2008)] i Pre-hadronic interaction scenario only simulates the interactions in the QGP without(!) explicit partonic interactions and phase transition => NOT (yet!) a consistent description! => P

12 R AA (J/Ψ) J/Ψ anomalous suppression at RHIC Au+Au, s 1/2 =200 GeV Prehadron interactions prehadronic interactions y < < y <2.2 B µµ dn(j/ψ)/dy central, 0-20% Au+Au, s 1/2 =200 GeV semi-central, 20-40% PHENIX y < < y < N part B µµ dn(j/ψ)/dy semi-peripheral, 40-60% y comover prehadron interactions PHENIX peripheral, 60-90% In the prehadronic interaction scenario, the J/Ψ rapidity distribution has the right shape, reproduces the PHENIX data! => describes R AA at mid- and forward-rapidity simultaneously. y [OL et al., NPA 807 (2008) 79 ]

13 Elliptic flow of D-mesons v 2 (J/Ψ) In+In, E beam =160 A GeV / / / / central peripheral NA60 Central / Peripheral v 2 (p T ) , D-mesons comover(+recombination) + prehadron interactions PHENIX PHENIX, QM'08 Au+Au, s 1/2 =200 GeV at SPS: v 2 is hadronic; 0.00 [OL et al., NPA 807 (2008) 79 ] at RHIC: p T [GeV/c] Default hadron comover scenario underestimates the data; Pre-hadron interactions lead to an increase of the elliptic flow v 2 of D mesons; The pre-hadronic scenario is ~consistent with the preliminary PHENIX data => strong initial flow of non-hadronic nature!

14 Elliptic flow of J/Ψ More data needed! 0.10 J/Ψ, Au+Au, s 1/2 =200 AGeV, y < v 2 (p T ) min bias comover + prehadron interactions [R.Granier de Cassagnac J Phys G 35 (2008) , C.Silvestre J Phys G 35 (2008) ] p T [GeV/c] [OL et al., arxiv: Int J Mod Phys (2008)]

15 Quenching of D mesons at RHIC Evidence of additional high p T suppression in the most central collisions. Suppression of D mesons in peripheral collisions is consistent with a purely hadronic scenario. [OL et al., arxiv: Int J Mod Phys (2008)]

16 Quenching of J/Ψ at RHIC Strong suppression at low p T observed experimentally cannot be explained: by hadronic absorption of initially produced J/Ψs R AA (p T ) J/Ψ from Au+Au, s 1/2 =200 GeV, mid-rapidity 0-20% centrality PHENIX, comover 20-40%, comover +prehadron interactions or by D+D recombination, since J/Ψs would follow R AA pattern similar to D mesons syst +/- 10% 40-60% centrality syst +/- 10% 60-92% centrality Possible indication of J/Ψ formation by parton coalescence! R AA (p T ) syst +/- 13% p T [GeV/c] syst +/- 28% p T [GeV/c] [OL et al., arxiv: Int J Mod Phys. E (2008)]

17 Conclusions In search for partonic phase signatures, an understanding of hadron (string) matter effects is necessary, and is the tool to model it Charm absorption at SPS is consistent with the hadronic comover picture But hadron comover absorption fails to describe the rapidity distribution of J/Ψ mesons from Au+Au at s 1/2 =200 GeV In the prehadronic interaction scenario, the data at s 1/2 =200 GeV for Au+Au at mid and forward rapidities are simultaneously reproduced However, RHIC data on high p T suppression and v 2 of D mesons are not reproduced in the (pre-)hadron-string picture => evidence for a plasma pressure?!

18 Review for Int. J. Modern Phys. E (September, 2008) arxiv:

19 Supression in pa at RHIC s 1/2 =200 GeV 1.0 R da PHENIX Charmonium is absorbed on baryons Effect of shadowing at forward y y [OL et al., NPA (2008) 807, 79]

20 J/Ψ and Ψ from threshold melting scenario at SPS Dissociation energy densities: ε(j (J/Ψ )=16 GeV/fm 3, ε(χ c ) =2 GeV/fm 3, ε(ψ ) =2 GeV/fm 3 B µµ σ(j/ψ)/σ(dy) B µµ (Ψ') σ / B (J/Ψ) σ Ψ' µµ J/Ψ NA Q G P threshold m elting ε =16, ε 3 J /Ψ =2, ε χ c Ψ ' =2 G ev /fm N part In+In, 158 A G ev Q G P threshold m elting ε =16, ε 3 J/Ψ =2, ε χ c Ψ ' =2 G ev /fm H SD N part H SD P b+pb, 158 A G ev NA Q G P threshold m elting ε =16, ε 3 J/Ψ =2, ε χ c Ψ ' =2 G ev /fm H SD N part NA NA Q G P threshold m elting ε =16, ε 3 J /Ψ =2, ε χ c Ψ ' =2 G ev /fm H SD E T [G ev ] (σ(j/ψ)/σ(dy)) / (σ(j/ψ)/σ(dy)) Glauber NA60, In+In, 158 A GeV QGP threshold melting NA50, Pb+Pb, 158 A GeV QGP threshold melting NA60, In+In, 158 A GeV (2007) N part J/Ψ suppression is qualitatively described, but QGP threshold melting scenario shows a too strong Ψ absorption, which contradicts the NA50 data! [OL et al., NPA 786 (2007) 183 ]

21 J/Ψ and Ψ from threshold melting scenario at RHIC R AA (J/Ψ) Au+Au, s 1/2 =200 GeV, QGP threshold scenario w ithout recombination PHEN IX, y <0.35 PHEN IX, 1.2< y <2.2 + recombination D+Dbar< > J/Ψ +m B µµ (Ψ') σ / B (J/Ψ) σ Ψ' µµ J/Ψ y < < y <2.2 [O Linnyk et al., PRC 76 (2007) ] Threshold melting model: complete dissociation of initial J/Ψ and Ψ due to the huge local energy densities! N part QGP threshold melting scenario is ruled out by PHENIX data! N part Charmonia recombination by D-DbarD Dbar annihilation is important, however, it can not generate enough charmonia, especially for peripheral collisions!

22 Summary Threshold scenario vs Comover absorption I. QGP threshold melting versus experimental data II. Comover absorption (+ recombination by D-Dbar D Dbar annihilation) versus experimental data SPS RHIC J/Ψ survival : + Ψ / J/Ψ ratio :? SPS RHIC J/Ψ survival : + Ψ / J/Ψ ratio : +? Comover absorption and threshold melting scenarios are ruled out by experimental data evidence for non-hadronic interaction?!

23 Bjorken energy density de T /dη/0.5n part [GeV] Au+Au, 200 GeV N part PHENIX ε Bj * τ [GeV/fm 2 /c] Au+Au, 200 GeV N part PHENIX ε Bj = 1 A τ de dy T Local energy density ε during transient time t r ~0.13 fm/c: ε 5[GeV/fm 2 /c] / [0.13 fm/c] ~ 30 GeV/fm 3 [OL et al., NPA (2008) 807, 79]

24 Local energy density from 5 Pb+Pb, 160 A GeV b=1 fm 4 ε(0,0,z) [GeV/fm 3 ] time [fm/c] z [fm] 10 At RHIC, energy-densities above the critical value (~2 GeV/fm 3 ) exist in an extended space-time area [OL et al., NPA 786 (2007) 183 ] [OL et al., NPA (2008) 807, 79]

25 Comparison to statistical hadronization 7 Pb+Pb, E beam =158 A GeV, mid-rapidity 40 Au+Au, s 1/2 =200 GeV, mid-rapidity <J/Ψ>/<π> <J/Ψ>/<π> Comover Comover QGP threshold Andronic et al QGP threshold Andronic et al Prehadron interactions N coll N coll [OL et al., NPA (2008) 807, 79]