RHIC LHC Determine the temperature ini BES

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RHIC LHC Determine the temperature ini BES Powered By Docstoc
					NQ-scaling for Phase Boundary

  F. Liu(1), K.J. Wu(1), and N. Xu(2)
(1) Institute of Particle Physics, China Center Normal University, Wuhan, China
(2) Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, 94720 CA, USA




Many Thanks to the Organizers!
                                     Outline


       (1) Introduction
       (2) Recent v2 results from RHIC
       (3) A proposal: using NQ scaling in v2 for
           locating the possible QCD phase boundary

       (4) Summary




Feng Liu          CBM China Meeting Nov. 2 – 4, 2009, Beijing, China   2/15
                       Elliptic Flow (v2)
                                                                       y 2  x2 
                                                                   
                                                                       y2  x2 

                                                                 Coordinate-Space
                                                                    Anisotropy

                                                                              interactions

                                                                 Momentum-Space
                                                                   Anisotropy
                                                                                         py
                                                          v2  cos 2 ,   tan 1 (        )
                                                                                         px

           partonic            hadronic

                                                         Strange hadron: less sensitive to
                                                        late hadronic rescattering
                                                         Elliptic flow =>
                                                           Early stage collision dynamics
                                                         Good probe of the early stage of
                 D    , Ω, Ξ, Λ      , K, p           the collision


Feng Liu                 CBM China Meeting Nov. 2 – 4, 2009, Beijing, China                       3/15
           200 GeV: Centrality Dependence
           STAR: Phys. Rev. C77, 54901(2008)
                    200 GeV Au+Au




                                                            S. Voloshin, A. Poskanzer, PL B474, 27(00).
                                                            D. Teaney, et. al., nucl-th/0110037



   Larger v2/part indicates stronger flow in more central collisions.
    NO partscaling.
    The observed nq-scaling does not necessarily mean thermalization.

Feng Liu                  CBM China Meeting Nov. 2 – 4, 2009, Beijing, China                      4/15
           System Size Driven Collectivity


                     STAR Preliminary




           Collectivity: Driven by number of participants,
                        NOT by eccentricity.
           Caution:     Local equilibrium andPerfect fluid
Feng Liu            CBM China Meeting Nov. 2 – 4, 2009, Beijing, China   5/15
                   φ-meson Flow: Partonic Flow
           STAR: Phys. Rev. Lett. 99, 112301(2007).




  “φ-mesons (and other hadrons) are produced via coalescence of
  seemingly thermalized quarks in central Au+Au collisions. This
  observation implies hot and dense matter with partonic
  collectivity has been formed at RHIC”
  STAR: Phys. Rev. Lett. 99, 112301(2007)


Feng Liu                       CBM China Meeting Nov. 2 – 4, 2009, Beijing, China   6/15
               Partonic Collectivity at RHIC

                                                       STAR: preliminary




                                                                             STAR: QM2009
                                                                               0907.2265

           Low pT(≤ 2 GeV/c): hydrodynamic mass ordering
           High pT (> 2 GeV/c): number of quarks ordering
           s-quark hadron: smaller interaction strength in hadronic medium
            light- and s-quark hadrons: similar v2 pattern
           => Collectivity developed at partonic stage!

Feng Liu                CBM China Meeting Nov. 2 – 4, 2009, Beijing, China          7/15
           Collectivity, De-confinement at RHIC
                                                           - v2 of light hadrons and
                                                             multi-strange hadrons
                                                           - scaling by the number
                                                             of quarks

                                                          At RHIC:
                                                           nq-scaling
                                                              novel hadronization
                                                              process
                                                          ê Partonic flow
                                                          De-confinement

                                                          PHENIX: PRL91, 182301(03)
                                                          STAR: PRL92, 052302(04), 95, 122301(05)
                           i    ii                              nucl-ex/0405022, QM05

                                                          S. Voloshin, NPA715, 379(03)
                                                          Models: Greco et al, PRC68, 034904(03)
                                                          Chen, Ko, nucl-th/0602025
                                                          Nonaka et al. PLB583, 73(04)
                                                          X. Dong, et al., Phys. Lett. B597, 328(04).
                                                          ….


Feng Liu          CBM China Meeting Nov. 2 – 4, 2009, Beijing, China                              8/15
                    The QCD Critical Point
                                                - LGT prediction on the transition
                                                temperature TC is robust.

                                                - LGT calculation, universality, and
                                                models hinted the existence of
                                                the critical point on the QCD phase
                                                diagram* at finite baryon chemical
                                                potential.

                                                - Experimental evidence for either
                                                the critical point or 1st order
                                                transition is important for our
                                                knowledge of the QCD phase
                                                diagram*.

                                                * Thermalization has been assumed
RHIC (200) & LHC: Determine the
temperature Tini, TC                             M. Stephanov, K. Rajagopal, and E. Shuryak, PRL 81,
                                                      4816(98);    K. Rajagopal, PR D61, 105017 (00)
BES: Explore the QCD phase diagram
                                                http://www.er.doe.gov/np/nsac/docs/Nuclear-Science.Low-
TE and the location phase boundary                     Res.pdf


Feng Liu              CBM China Meeting Nov. 2 – 4, 2009, Beijing, China                           9/15
STAR experience with Low Energy RHIC running
                                                observed apparent rates of collisions surprisingly high (?!)
2001: 19.6 GeV Au+Au
                                                to do: (1) understand background
2004: 22.4 GeV Cu+Cu
2007: 9 GeV Au+Au                                        (2) optimize triggering



     Collectivity from STAR at 9.2GeV




                  STAR TPC image of 9 GeV Au+Au, taken on June 7, 2007 (run 8158119, ev.44), figure from Jeff Langraf


                                                                                           10
Feng Liu                 CBM China Meeting Nov. 2 – 4, 2009, Beijing, China                                             10/15
 STAR Experiment and Collisions at Ecm= 9.2 GeV
Collisions recorded in STAR TPC
                                                 Excellent Particle Identification




                                     Analysis based on ~ 3000 good events
                                     collected at ~ 0.7 Hz in year 2008
                                     PID will further strengthen with the
                                     completion of ToF

                                                                        11
Feng Liu           CBM China Meeting Nov. 2 – 4, 2009, Beijing, China         11/15
           Azimuthal Anisotropy - Elliptic Flow




    QM08 Lokesh Kumar for STAR
    With TOF, the pt region will be extended to a higher value.
    Important to perform the v2 scaling analysis.

                                                                             12
Feng Liu                CBM China Meeting Nov. 2 – 4, 2009, Beijing, China        12/15
                                 RHIC run 10 (fall 2009)

(1) Large energy range accessible
(2) Collider geometry (acceptance won’t change with S, track density varies slowly)
(3) STAR detectors well suited (large acceptance), tested & understood

           STAR PAC 2007 Strawman proposal:

        sNN [pft]        B      <BBC Rate>          Days/           # events     # beam days
       GeV [GeV/c]      [MeV]        [Hz]             Mevent
           4.6 [9.6]    570             3                 9              5M            45
           6.3 [18.8]   470             7                 4              5M            20
           7.6 [27.9]   410             13                2              5M            10
           8.8 [37.7]   380             20               1.5             5M            7.5
           12 [71.0]    300             54               0.5             5M            2.5
           18 [161]     220           >100              0.25             5M            1.5
           28 [391]     150           >100              0.25             5M            1.5


  Note: NA61 @ CERN (starting in 2010): 10, 20, 30, 40, 80, 158 GeV/c

Feng Liu                      CBM China Meeting Nov. 2 – 4, 2009, Beijing, China                 13/15
           Au+Au Collisions at 9.2 GeV AMPT (v2.1)




                                                       J. Tianet al, Phys. Rev. C79, 067901(2009).

      (a) Patonic matter: coalescence of (b) Hadronic matter:rescatterings
         massive quarks for hadronization  amongst hadrons

  Clear NQ scaling in v2 !                     No NQ scaling in v2 !

Feng Liu               CBM China Meeting Nov. 2 – 4, 2009, Beijing, China                     14/15
           Au+Au Collisions at 9.2 GeV AMPT (v2.1)

                              σp = 3mb                          AMPT model results:

                                                                1) In AMPT, the scaling in
                                                                   v2 is independent of
                                                                   partonic cross sections

                                                                2) The amplitude of v2
                                                                   depends on the value
                                                                   of the cross section
                              σp = 10mb
                                                                =>
                                                                The beam energy
                                                                   dependence of the
                                                                   partonic cross
                                                                   sections will not
                                                                   affect the v2 scaling
                                                                   argument. Important
                                                                   for BES program.


Feng Liu           CBM China Meeting Nov. 2 – 4, 2009, Beijing, China                15/15
               RQMD and uRQMD Results




       1) These hadronic models predicted a lower v2(pT) compare to that
          from AMPT hadronic mode calculations.
       2) They also show a scaling better than that from AMPT hadronic
          mode calculations, due to the number of quark scaling in hadron
          cross sections used.
       3) Multi-strange hadrons, φ and Ω, for example, are important for a
          clean measurement.

Feng Liu                CBM China Meeting Nov. 2 – 4, 2009, Beijing, China   16/15
        Observable*: Quark Scaling in v2




                                             -m ~ mp ~ 1 GeV
                                             -ss φnot K+K- φ
                                             -h<<p, 

                                             In the hadronic case, no number
                                             of quark scaling and the value of
                                             v2ofφ will be small.

                                             * Thermalization is assumed!
Nu Xu        SQM2009, Buzios - Brazil, September 27 – October 2, 2009       17/15
Energy Dependence of the v2-scaling and the QCD Phase Boundary


Summary
1)NQ scaling in v2: partonic collectivity&de-
confinement in high-energy nuclear collisions.
2)Scaling in v2:   partonic dofdominants
  No scaling in v2: hadronic dofdominants
3)The multi-strange hadrons are particularly clean for
the search, φ, for example.
3)Together with other observables:
Fluctuations, Kurtosis, LPV, clusters …

F. Liu(1), K.J. Wu(1), and N. Xu(2)

(1) Institute of Particle Physics, China Center Normal University, Wuhan, China
(2) Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, 94720 CA, USA
           Tests withφ-mesons in uRQMD




                                                      1) φ-mesons from string
                                                         show weak collectivity
                                                         &does not follow the
                     (/4)                                nq-scaling.

                                                      2) Coalescence φ-
                                                         mesons from K+K- (/4)
                                                         fit the nq-scaling in
                                                         pT<= 2 GeV/c region.




Feng Liu        CBM China Meeting Nov. 2 – 4, 2009, Beijing, China                19/15
                    Anisotropy Parameter v2
           coordinate-space-anisotropy                    momentum-space-anisotropy


                        y




                                          x




                  Initial/final conditions, EoS, degrees of freedom

Feng Liu                    CBM China Meeting Nov. 2 – 4, 2009, Beijing, China        20/15
                 MC vs. AuAu@9.2GeV Data

                                        Lokesh Kumar QM2009, SQM2008




            Only 3k good events for the experimental data.
             v2 : AMPT with melting > AMPT default > UrQMD >RQMD.
                 Partonic reactions enhance hadrons v2 !


Feng Liu                 CBM China Meeting Nov. 2 – 4, 2009, Beijing, China   21/15
               The QCD Phase Diagram and
               High-Energy Nuclear Collisions

           1           Ti, TC                                  2    TE                     3      Phase Boundary
                       LHC, RHIC                                    RHIC, FAIR                    RHIC,FAIR, NICA
                             Early Universe




                                                                         quark-gluon plasma
                                              1             2
               Temperature




                                                                           3
                                 Tc               Critical Point?


                                                               hadron gas
                                                                                               CSC
                                                                          nuclei


                                                            Baryon Chemical Potential

Feng Liu                                           CBM China Meeting Nov. 2 – 4, 2009, Beijing, China               22/15
                MC vs. Experimental data




            Only 3k good events for experimental data.
            Difficult to say which MC model is best suitable.

Feng Liu                 CBM China Meeting Nov. 2 – 4, 2009, Beijing, China   23/15

				
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