Heavy Flavors at FAIR Elena Bratkovskaya , WE-Heraeus-Seminar „Characterization of the Quark Gluon Plasma with Heavy Quarks‘‘, Bad Honnef (Germany) Bad Honnef (Germany)

Introduction FAIR energies are well suited to study dense and hot nuclear matter –  a phase transition to QGP,  chiral symmetry restoration,  in-medium effects Observables for CBM: Observables for CBM:  Excitation function of particle yields and ratios  Transverse mass spectra  Collective flow  Dileptons  Open and hidden charm  Fluctuations and correlations ... The way to study: Experimental energy scan of different observables in order to find an ‚anomalous‘ behaviour in comparison with theory Microscopic transport models provide a unique dynamical description of nonequilibrium effects in heavy-ion collisions

HSD – Hadron-String-Dynamics transport approach HSD – Hadron-String-Dynamics transport approach for each particle species i (i = N, R, Y, , , K, …) the phase-space density f i follows the transport equations for each particle species i (i = N, R, Y, , , K, …) the phase-space density f i follows the transport equations with collision terms I coll describing: with collision terms I coll describing:  elastic and inelastic hadronic reactions: baryon-baryon, meson-baryon, meson-meson baryon-baryon, meson-baryon, meson-meson  formation and decay of baryonic and mesonic resonances  string formation and decay ( for inclusive particle production: BB  X, mB  X, X =many particles) BB  X, mB  X, X =many particles) implementation of detailed balance on the level of 1  2 implementation of detailed balance on the level of 1  2 and 2  2 reactions (+ 2  n multi-particle reactions in HSD) and 2  2 reactions (+ 2  n multi-particle reactions in HSD) off-shell dynamics for short-lived states off-shell dynamics for short-lived states Basic concept of HSD BB  B´B´, BB  B´B´m mB  m´B´, mB  B´ Baryons: B=(p, n, , N(1440), N(1535),...) Mesons: m=( , , 

very good description of particle production in pp, pA reactions very good description of particle production in pp, pA reactions unique description of nuclear dynamics from low (~100 MeV) to ultrarelativistic (~20 TeV) energies unique description of nuclear dynamics from low (~100 MeV) to ultrarelativistic (~20 TeV) energies HSD – a microscopic model for heavy-ion reactions HSD 1999 predictions AGSNA49BRAHMS

Open and hidden charm  Hidden charm: J/ ,  ‘: Anomalous J/  suppression in A+A (NA38/NA50/NA60) Heavy flavor sector reflects the early dynamics since heavy hadrons can only be formed in the very early phase of heavy-ion collisions at FAIR/SPS! J/  ‚normal‘ absorption by nucleons (Glauber model) || Experimental observation: extra suppression in A+A collisions; increasing with centrality

Quarkonium dissociation temperatures: I.-II. Scenarios for charmonium suppression in A+A I. QGP threshold melting I. QGP threshold melting [Satz et al’03] Digal, Fortunato, Satz hep-ph/ Dissociation energy density  d ~ 2(T d /T c ) 4 J/   C melting II. Comover absorption II. Comover absorption [Gavin & Vogt, Capella et al.`97]: charmonium absorption by low energy inelastic scattering with ‚comoving‘ mesons (m=  J/  +m  D+Dbar J/  +m  D+Dbar  ‘+m  D+Dbar  C +m  D+Dbar

Charm and Charmonium production and absorption in HSD Coupled channel problem:  J/  exp =  J/  + B (  c ->J/  )   c + B (  ‘ ->J/  )   ‘ Charmonium = hard probe Charmonium = hard probe => binary scaling! => binary scaling! Production  (J/  )  (  ‘ ) in N+N and  +N collsions: parametrization of the available exp. data Production  (J/  ) and  (  ‘ ) in N+N and  +N collsions: parametrization of the available exp. data Charmonia-baryon dissociation cross Charmonia-baryon dissociation cross sections can be fixed from p+A data:  cc B =  J/  B =   B = 4.18 mb,   ‘ B = 7.6 mb (adopting a Glauber fit from NA50) (adopting a Glauber fit from NA50) J /  (  c,  ‘) + B --> D+Dbar +X J /  (  c,  ‘) + B --> D+Dbar +X

II. Modelling of the comover scenario in HSD Phase-space model for charmonium + meson dissociation: Phase-space model for charmonium + meson dissociation: PRC 67 (2003) J /  recombination cross sections by D+Dbar annihilation: D+Dbar -> J /  (  c,  ‘) + meson ( , K, K*) are determined bydetailed balance! are determined by detailed balance! constant matrix element 1. Charmonia dissociation cross sections with formed , K and K* mesons J /  (  c,  ‘) + meson ( , K, K*)  D+Dbar 1. Charmonia dissociation cross sections with formed , K and K* mesons J /  (  c,  ‘) + meson ( , K, K*)    D+Dbar Note: comover dissociation as well as DDbar recombination can occure only if the local energy density at the collision point  < 1GeV/fm 3

At SPS recreation of J/  by D+Dbar annihilation is negligible but at RHIC recreation of J/  by D+Dbar annihilation is strong! (II.) Charmonium recombination by D-Dbar annihilation N DD ~16 PRC 67 (2003)

I. Modelling of the QGP melting scenario in HSD Olena Linnyk et al., nucl-th/ , NPA 786 (2007) 183; arXiv: , NPA 807 (2008) 79 Threshold energy densities: J  melting:  (J  )=16 GeV/fm 3  c melting:  (  c ) =2 GeV/fm 3  ‚  melting:  (  ‚ ) =2 GeV/fm 3 Energy density  (x=0,y=0,z;t) from HSD Energy density  (x=0,y=0,z;t) from HSD for Pb+Pb collisions at 160 A GeV Energy density  (x=0,y=0,z;t) from HSD Energy density  (x=0,y=0,z;t) from HSD for Au+Au collisions at A GeV

(I.) ‚Local‘ energy density  versus Bjorken energy density  Bj transient time for central Au+Au at 200 GeV: transient time for central Au+Au at 200 GeV: t r ~ 2R A /  cm ~ 0.13 fm/c t r ~ 2R A /  cm ~ 0.13 fm/c c-cbar formation time: c-cbar formation time:   C ~ 1/M T ~ 1/4GeV ~ 0.05 fm/c < t r c-cbar pairs are produced in the initial hard NN c-cbar pairs are produced in the initial hard NN collisions in time period t r collisions in time period t r Bjorken energy density: Bjorken energy density: J  cccc  ‚ ‚ ‚ ‚ at RHIC  Bj  ~ 5 GeV/fm 2 /c at RHIC  Bj  ~ 5 GeV/fm 2 /c A  is the nuclei transverse overlap area  is the formation time of the medium ‚Local‘ energy density  during transient time t r   GeV/fm 2 /c] / [0.13 fm/c] ~ 30 GeV/fm 3 ~ 30 GeV/fm 3 accounting  C :   ~ 28 GeV/fm 3 HSD reproduces PHENIX data for Bjorken energy density very well HSD reproduces PHENIX data for Bjorken energy density very well HSD results are consistent with simple estimates for the energy density HSD results are consistent with simple estimates for the energy density

J/  and  ´ suppression in In+In and Pb+Pb at SPS: (II.) Comover absorption (+ recombination by D-Dbar annihilation) Exp. data (NA50/NA60) for J/  and  ´ suppression for Pb+Pb and In+In at 160 A GeV are consistent with the comover absorption model for the same set of parameters! Exp. data (NA50/NA60) for J/  and  ´ suppression for Pb+Pb and In+In at 160 A GeV are consistent with the comover absorption model for the same set of parameters! [Olena Linnyk et al., nucl-th/ , NPA 786 (2007) 183 ]

J/  and  ´ suppression in In+In and Pb+Pb at SPS: (I.) QGP threshold melting scenario J/  suppression is qualitatively described, butQGP threshold melting scenario shows a too strong  ‚ absorption, which contradicts the NA50 data! J/  suppression is qualitatively described, but QGP threshold melting scenario shows a too strong  ‚ absorption, which contradicts the NA50 data! Dissociation energy density:   (J  )=16 GeV/fm 3,  (  c ) =2 GeV/fm 3,  (  ‚ ) =2 GeV/fm 3 [Olena Linnyk et al., nucl-th/ , NPA 786 (2007) 183 ]

J/  and  ´ suppression in Au+Au at RHIC: (II.) Comover absorption (+ recombination by D-Dbar annihilation) In the comover scenario the J/  suppression at mid-rapidity is stronger than at forward rapidity, unlike the data! Pure comover scenario is ruled out by PHENIX data! Olena Linnyk et al., nucl-th/ , NPA 786 (2007) 183; arXiv: , NPA 807 (2008) 79

QGP threshold melting scenario is ruled out by PHENIX data! J/  and  ´ suppression in Au+Au at RHIC: (I.) QGP threshold melting scenario Satz’s model: complete dissociation of initial J/  and  ´ due to the huge local energy densities ! Charmonia recombination by D-Dbar annihilation is important, however, it can not generate enough charmonia, especially for peripheral collisions! [Olena Linnyk et al., arXiv: , arXiv: , PRC 76 (2007) ]

Summary (I.-II. ) I. QGP ‚threshold melting‘ I. QGP ‚threshold melting‘ versus experimental data versus experimental data SPS RHIC SPS RHIC J/  survival  :  +   ‚ / J/  ratio :    ? II. Comover absorption II. Comover absorption (+ recombination by D-Dbar annihilation) versus experimental data versus experimental data SPS RHIC SPS RHIC J/  survival  :  +   ‚ / J/  ratio :    ? Comover absorption and threshold melting scenarios are ruled out by experimental data evidence for non-hadronic interaction ?! evidence for non-hadronic interaction ?!

III. Scenarios for charmonium suppression in A+A III. Pre-hadronic interaction scenario : III. Pre-hadronic interaction scenario :  early interactions of charmonium (ccbar) and D-mesons with unformed (i.e. under formation time t =  F,  F ~0.8 fm/c in the hadron rest frame) baryons and mesons - pre-hadrons  + comover absorption with recombination by D-Dbar annihilation  Dissociation cross sections of charmonium by pre-hadrons:  dis cc pre-Baryon = 5.8 mb,  dis cc pre-meson = 2/3  dis cc pre-Baryon  Elastic cross sections with prehadrons: Charmonium - prehadrons:D-meson - prehadrons:  el cc pre-Baryon = 1.9 mb,  el D pre-Baryon = 3.9 mb,  el cc pre-meson = 2/3  el cc pre-Baryon  el D pre-meson = 2/3  el cc pre-Baryon  Pre-hadronic interaction scenario only ‚simulates‘ the interactions in the QGP in the Hadron-String model without (!) explicit partonic interactions and phase transition => NOT (yet!) a consistent description ! => PHSD Fitted to PHENIX data

J/  and  ´ suppression in Au+Au at RHIC: (III.) Pre-hadronic interaction scenario In the prehadronic interaction scenario the J/  rapidity distribution has the right shape like the PHENIX data! => can describe the RHIC data at s 1/2 =200 GeV for Au+Au at mid- and forward-rapidities simultaneously. Olena Linnyk et al., arXiv: , NPA 807 (2008) 79

J/  and  ´ suppression in Au+Au at RHIC PHENIX data:  evidence for non-hadronic interactions of charm degrees of freedom ! Olena Linnyk et al., arXiv: , NPA 807 (2008) 79

Comover reactions in the hadronic phase give almost a constant suppression; Comover reactions in the hadronic phase give almost a constant suppression; pre-hadronic reactions lead to a larger recreation of charmonia with E beam The J/  melting scenario with charmonia recombination by DDbar annihilation shows a maximum suppression at E beam = 1 A TeV; The J/  melting scenario with charmonia recombination by DDbar annihilation shows a maximum suppression at E beam = 1 A TeV; exp. data ? exp. data ? J/  excitation function [Olena Linnyk et al., arXiv: , NPA 807 (2008) 79 ] FAIR FAIR

 ´ suppression provides independent information on absorption versus recreation mechanisms !  ´ excitation function [Olena Linnyk et al., arXiv: , PRC 76 (2007) ] FAIR FAIR [Olena Linnyk et al., arXiv: , NPA 807 (2008) 79 ]

HSD predictions for J/  and  ´ suppression in Au+Au at CBM energies Different scenarios can be distinguished already at FAIR energies:  ´ over J/  ratio is lower in the comover absorption model since the average comover density decreases only moderately with lower bombarding energy whereas the energy density decreases rapidly [Olena Linnyk et al., arXiv: , PRC 76 (2007) ]

HSD: v 2 of D+Dbar and J/  from Au+Au versus p T and y at RHIC Pre-hadronic interactions lead to an increase of the elliptic flow v 2 Pre-hadronic interactions lead to an increase of the elliptic flow v 2 The pre-hadronic interaction scenario is ~consistent with the preliminary PHENIX data on the D-mesons v 2 The pre-hadronic interaction scenario is ~consistent with the preliminary PHENIX data on the D-mesons v 2 => strong initial flow of non-hadronic nature! => strong initial flow of non-hadronic nature! [Olena Linnyk et al., arXiv: , NPA 807 (2008) 79 ]

HSD predictions for CBM - elliptic flow at 25 A GeV Challenge for CBM! HSD: D-mesons and J/  follow the charged particle flow  small v 2 HSD: D-mesons and J/  follow the charged particle flow  small v 2 Possible observation at CBM: strong initial flow of D-mesons and J/  due to partonic interactions! strong initial flow of D-mesons and J/  due to partonic interactions!

J/  probes early stages of fireball and HSD is the tool to model it. J/  probes early stages of fireball and HSD is the tool to model it. Comover absorption and threshold melting: both reproduce J/  survival in Pb+Pb as well as in In+In at SPS, while  ´/J/  data appear to be in conflict with the ‚melting scenario‘. Comover absorption and threshold melting: both reproduce J/  survival in Pb+Pb as well as in In+In at SPS, while  ´/J/  data appear to be in conflict with the ‚melting scenario‘. Comover absorption and threshold melting fail to describe the RHIC data at s 1/2 =200 GeV for Au+Au at mid- and forward- rapidities simultaneously Comover absorption and threshold melting fail to describe the RHIC data at s 1/2 =200 GeV for Au+Au at mid- and forward- rapidities simultaneously Prehadronic interaction scenario can describe the RHIC data at s 1/2 =200 GeV for Au+Au at mid- and forward-rapidities simultaneously Prehadronic interaction scenario can describe the RHIC data at s 1/2 =200 GeV for Au+Au at mid- and forward-rapidities simultaneously STAR data on v 2 of high p T charged hadrons and charm D mesons are not reproduced in the hadron-string picture => evidence for a plasma pressure ?! STAR data on v 2 of high p T charged hadrons and charm D mesons are not reproduced in the hadron-string picture => evidence for a plasma pressure ?! Summary

FAIR is an excellent facility to study the properties of the sQGP (strongly interacting ‚color liquid‘) as well as hadronic matter FAIR is an excellent facility to study the properties of the sQGP (strongly interacting ‚color liquid‘) as well as hadronic matter Outlook Transport theory is the general basis for an understanding of nuclear dynamics on a microscopic level Transport theory is the general basis for an understanding of nuclear dynamics on a microscopic level UrQMD: U+U, 25 A GeV

Thanks to Olena Linnyk Wolfgang Cassing Horst Stöcker

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D+Dbar transverse p T spectra from Au+Au – HSD predictions Interactions (inelastic and elastic) of D/Dbar and J/  with hadronic medium change the shape of the initial spectra (i.e. at the production point). Interactions (inelastic and elastic) of D/Dbar and J/  with hadronic medium change the shape of the initial spectra (i.e. at the production point). However, a full thermalization of charm (charmonium) p T spectra is NOT achieved in the hadron- string model [E. B., W. Cassing, H. Stöcker, N. Xu, PRC 71 (2005) ] (II.) Comover absorption (+ recombination by D-Dbar annihilation)

Supression in cold nuclear matter Charmonium is absorbed by scattering on baryons [OL et al., arXiv: ]