Presentation is loading. Please wait.

Presentation is loading. Please wait.

T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 Nucleon Structure and Quark-Gluon-Plasma: HERMES and ALICE/STAR Thomas Peitzmann Utrecht University/NIKHEF.

Similar presentations


Presentation on theme: "T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 Nucleon Structure and Quark-Gluon-Plasma: HERMES and ALICE/STAR Thomas Peitzmann Utrecht University/NIKHEF."— Presentation transcript:

1 T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 Nucleon Structure and Quark-Gluon-Plasma: HERMES and ALICE/STAR Thomas Peitzmann Utrecht University/NIKHEF

2 T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 Outline HERMES –fragmentation in nuclei STAR –elliptic flow –jet physics ALICE –silicon strip detector –analysis preparations

3 T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 NIKHEF Research programs LHCb & Babar ATLAS & D0 ALICE & STAR Antares Theory R&D GRID Outreach LEP HERA ~16 M per annum excluding investments 2005

4 T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 HERMES HERA/DESY investigate spin structure of the nucleon –DIS with polarized leptons on polarized hydrogen target fragmentation in the nucleus –lepto-production of hadrons off nuclei hardware contribution from NIKHEF: Lambda wheels

5 T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 HERMES spin decomposition Analysis highlights: N spin decomposition hyperon production transversity PhDs: 10 completed 7 institutes abroad +5 in preparation Publications: expect ~100 by 2007

6 T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 Absorption/Energy Loss in Nuclei? production of hadrons in nuclei vs deuterium significant suppression of large z hadrons in heavy nuclei –absorption? –energy loss?

7 T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 Fragmentation in the Nucleus? ratio of di-hadron to single hadron for different nuclei very little dependence on mass of nucleus important reference measurement for heavy ion collisions

8 T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 ALICE/STAR 7 PhD –4 STAR, 3 ALICE 45 publications –STAR from 2002 up to now group will shift completely to ALICE in the near future part of one FOM programme ALICE at LHC/CERN –hardware contribution: silicon strip detector –data taking from 2007 STAR at RHIC/BNL –joined in 2002 –data taking and analysis

9 T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 QCD phase diagram QCD predicts transition from hadronic phase to a quark-gluon-plasma –T c MeV –order of transition unknown (but much larger number of d.o.f.) –deconfinement and chiral symmetry restoration studied in high-energy heavy ion collisions

10 T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 The focus of our group The properties of the QCD Equation of State above T c –dp/d calculable in lattice QCD –observables: collective motion of low transverse momentum particles as function of mass The color density of hot and dense QCD matter –induced soft gluon radiation by partons traversing the medium –observables: medium modifications of jets and heavy particle production

11 T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 The STAR Detector MagnetCoilsCentralTriggerBarrel(CTB)ZCalTimeProjectionChamber(TPC) Year 2000 Barrel EM Cal (BEMC) Silicon Vertex Tracker (SVT) Silicon Strip Detector (SSD) FTPC Endcap EM Cal FPD TOFp, TOFr FPD Year PMD

12 T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 Elliptic flow

13 T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 Collective motion: velocity of sound buildup of collective flow depends on the magnitude of the velocity of sound and the relative time spend in various phases sensitive to difference in equation of state (EoS) P.F. Kolb and U. Heinz, in Quark Gluon Plasma, nucl-th/

14 T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 Self-quenching of elliptic flow the driving force of elliptic flow (anisotropy of pressure gradient) dominates at early times elliptic flow monitors early collective (i.e. equilibrated) behaviour P.F. Kolb and U. Heinz, in Quark Gluon Plasma, nucl-th/

15 Measurement of elliptic flow asymmetry of number distribution of particles with respect to the reaction plane Fourier-decomposition: strong 2. order (v 2 ) early result from STAR: strength of elliptic flow reaches predictions of ideal hydrodynamics at RHIC STAR charged hadrons ideal hydrodynamics

16 T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 Identified particle flow hierarchy of momentum dependent flow for different hadrons –onset of v 2 shifts to larger p T for heavier particles –consistent with ideal hydrodynamics –magnitude of difference not consistent with hadron gas, but with QGP parallel talk by Bai Yuting

17 T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 Jets and jet quenching

18 T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 Parton energy loss: current understanding collisional energy loss –original idea by Bjorken –very small effect more important: induced gluon radiation interference leads to non-linearity dominant feature: –energy loss determined by density of color charges parameterized by transport coefficient

19 T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 p+p dijet+XAu+Au ??? Measuring jets in AA? how to find this in here? two observables: - high p T single hadron distributions - dihadron distributions

20 T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 Inclusive Hadron Suppression nuclear modification factor suppression requires initial density 30x larger than cold nuclear matter –compare to HERMES results very close to maximum suppression –provides only lower bound on density Eskola et al., hep-ph/

21 T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 Surface emission large energy loss: opaque core –emissions from surface inclusive measurements insensitive above certain density –more information from correlation measurements? ? Eskola et al., hep-ph/

22 T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 Dihadrons in heavy ion collisions near-side correlation unchanged away-side peak suppressed in central Au+Au –consistent with surface emission distributions in d+Au similar to p+p –suppression is final state effect more intuitive hint for jet suppression, but quantitatively much more difficult

23 T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 Emergence of away-side peak p T (trig) p T (assoc) > 2 GeV/c STAR Preliminary Au+Au, 0-5% High statistics year 4 dataset allows increase in Q 2 Emergence of the away side peak with increased trigger p T Equivalent to year 2 analysis

24 T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 Emergence of dijets increase associated p T threshold also: clear jet-like peaks seen on near and away side in central Au+Au collisions! yields info on upper and lower limit of density! 8 < p T (trig) < 15 GeV/c STAR Preliminary p T (assoc)>6 GeV

25 T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 Where does the energy go? Leading hadrons Medium significant softening of associated hadrons! mean p T of away-side associated hadrons = remaining jet fragments?

26 T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 The perfect fluid at RHIC, the wQGP at the LHC? wQGP = weakly- interacting plasma less flow at higher energies? beware: remember the predictions for RHIC!

27 T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 Elliptic flow at LHC energies from ideal hydrodynamics Whatever the outcome will be, elliptic flow is a day-one measurement at the LHC with very likely similar impact as at RHIC From Heinz, Kolb, Sollfrank

28 T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 ALICE: the dedicated HI experiment Solenoid magnet 0.5 T Central tracking system: ITS TPC TRD TOF MUON Spectrometer: absorbers tracking stations trigger chambers dipole Specialized detectors: HMPID PHOS Forward detectors: PMD FMD, T0, V0, ZDC Cosmic rays trigger

29 T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 The Alice ITS FE moduleFE module EndcapEndcap FEROMFEROM DAQDAQ SSD Support and coolingSupport and cooling Main vertex 15 µ m in central PbPb Vertex charm, strange decays 50 µ m Δp/p (p T >1 GeV, with TPC) 14%->3% Particle ID (dE/dx) Strong contribution to outer layers (SSD) project leader SSD (6 labs)

30 T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 SSD: the first real ladder!

31 T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 NIKHEF/UU ALICE hardware activities (SSD) Design of SSD support (with Turin) Design ladder frames (with St. Petersburg) Design of SSD cooling system (with CERN) Design of front-end modules (with Kharkov and Strasbourg) Design ladder cabling (with Kharkov) Design SSD cabling (industrial production) Design and production of front-end module test equipment Design and production of EndCap electronics Design and production of read-out modules Ladder assembly (with Nantes) Final SSD assembly Bottom line: ITS project on schedule and NIKHEF SSD contribution will finish on time (2006)

32 T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 ALICE group: current manpower Utrecht and NIKHEF Amsterdam Amsterdam manpower: –Staff physicist: 3 –PhD students: 2 Utrecht manpower: –Staff physicist: 4 –Post-doc: 1 –PhD students: 5 –Students: 2 Amsterdam infrastructure: –Mechanical and electronics workshop –Ladder assembly room Utrecht infrastructure: –Faculty mechanical and electronics workshop –Mechanical and electronic workshop of the SAP department (4 fte) –Assembly room

33 T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 ALICE group: current physics activities Have strong role in STAR EMC analysis –1 fte staff, 1 post-doc, 3 PhD's (until 2009) and 2 students Had a leading role in correlation analysis with the reaction plane in STAR –Effort is scaled down to 1 PhD (until 2007) and 0.2 fte staff Have a coordinating role in correlation analysis with the reaction plane in ALICE (Physics Performance Report) –Effort 4 fte staff and 2 PhD –Will increase further with 3 PhDs and 1 post-doc

34 T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 Summary important nuclear physics contributions from NIKHEF –HERMES with nuclear physics program in parallel to spin –ALICE/STAR nuclear physics at the highest energies rich physics harvest from STAR –elliptic flow –jet quenching ALICE well under way for data taking in 2007 –strong Dutch contribution to SSD –prepare physics analysis elliptic flow as day-one topic


Download ppt "T. Peitzmann, NUPECC Groningen, Nov. 18, 2005 Nucleon Structure and Quark-Gluon-Plasma: HERMES and ALICE/STAR Thomas Peitzmann Utrecht University/NIKHEF."

Similar presentations


Ads by Google