Experimental High-energy Heavy-ion Physics in Heidelberg Kai Schweda 66th NuPECC meeting, Egelsbach 10 Oct 2009

Heavy-ion group at Heidelberg group leader: J. Stachel faculty: P. Glässel, N. Herrmann, K. Reygers, R. Schicker, K.S. 9 postdocs 10 Ph.D. students 3 diploma students 5 junior researchers 3 engineers 10 Oct 2009 66th NuPECC meeting, Egelsbach

Phase diagram of strongly interacting matter ALICE at LHC: explore high-energy frontier CBM at FAIR: explore high baryon-density frontier 10 Oct 2009 66th NuPECC meeting, Egelsbach

ITS: measures secondary vertex, open heavy-flavor, c and b Size: 16 x 26 meters Weight: 10,000 tons Detectors: 18 TRD ITS TPC ITS: measures secondary vertex, open heavy-flavor, c and b TPC: tracks and identifies charged particles, (e,), , K, p TRD: identifies electrons above 1 GeV, fast trigger (6s) 3

66th NuPECC meeting, Egelsbach ALICE TPC Calibration TPC installed in ALICE, running continuously May-October 2008, and since Aug 2009 100 million events (cosmics, krypton, and laser) recorded Second iteration of calibration completed, more to come transverse momentum resolution particle identification via dE/dx dE/dx resolution: measured <5% design 5.5% resolution at 10 GeV: measured 6.5% design 4.5% performance meets design, TPC ready for collisions 10 Oct 2009 66th NuPECC meeting, Egelsbach

66th NuPECC meeting, Egelsbach TRD commissioning 7/18 supermodules installed in ALICE cosmic ray data taking in 2008 and 2009 horizontal tracks acquired (TRD L1 trigger commissioned and used) reconstruction and first iteration for calibration parameters (gain, drift velocity) completed cosmic event triggered by TRD L1 Tracking in TPC and 2 TRD SM Uniformity better than 10% Run 85752, event 8 10 Oct 2009 66th NuPECC meeting, Egelsbach

TRD readout electronics 2 custom designed ASICS - pre-amplifier/shaper (PASA) - ADC/tracklet-processor (TRAP): contain 275k CPUs to process 65 MBytes of raw data tracking and trigger decision within 6.5s selection of high momentum electrons 70kW cooling power required PASA TRAP Multi Chip Module (MCM) 10 Oct 2009 66th NuPECC meeting, Egelsbach

HD contribution to TRD of ALICE Technical coordination Infrastructure at CERN Installation and commissioning at CERN Construction and electronics development Chamber testing Electronics integration and pretrigger Detector control system Data quality and integrity assurance Alignment Online monitoring Noise analysis 10 Oct 2009 66th NuPECC meeting, Egelsbach

HD contribution to TPC of ALICE Technical coordination Electronics development 10 Oct 2009 66th NuPECC meeting, Egelsbach

Fast parton probing the medium z = p(h)/pparton Ejet  pparton Eγ = pparton p ≠ pparton Leading Hadron quark-gluon plasma Fast parton emerges in spray of collimated hadrons  jet Measure hadron distribution f(z)  fragmentation function Medium modification of f(z) compared to vacuum  probe QGP 10 Oct 2009 66th NuPECC meeting, Egelsbach

66th NuPECC meeting, Egelsbach Jet- quenching Nuclear modification factor: Energy loss of parton leads to deficit of hadrons at large momentum No “Effect”: R < 1 at small momenta R = 1 at higher momenta where hard processes dominate Jet-quenching: Suppression: R < 1 10 Oct 2009 66th NuPECC meeting, Egelsbach

66th NuPECC meeting, Egelsbach b-quark tagged jets novel effects for heavy-quarks predicted quark vs. gluon energy loss in the medium  exp. access to color factor  challenge to models b-quark jets are pure samples of quark jets harder fragmentation of the b-quark jet-energy is known more precisely better handle on the fragmentation function S. Wicks et al., NPA 784, (2007) 426. 10 Oct 2009 66th NuPECC meeting, Egelsbach

Heavy - flavor: a unique probe mc,b » QCD : new scale mc,b ≈ const., mu,d,s ≠ const. initial conditions: test pQCD, R, F probe gluon distribution early partonic stage: diffusion (), drag () flow, jets, correlations probe thermalization hadronization: chiral symmetry restoration confinement statistical coalescence J/ enhancement / suppression Q2 time X. Zhu, M. Bleicher, S.L. Huang, K.S., H. Stöcker, N. Xu, and P. Zhuang, PLB 647 (2007) 366. 10 Oct 2009 66th NuPECC meeting, Egelsbach

Where does all the charm go ? J c Ds D0 D± Statistics plot: H. Yang and Y. Wang, U Heidelberg. Total charm cross section: open charm hadrons, e.g. D0, D*, c, … or c,b  e() + X Quarkonia, e.g. J/ carries 1% of total charm 10 Oct 2009 66th NuPECC meeting, Egelsbach

Heavy-quark detection e.g., D0  K- +  , c = 123 m displaced decay vertex is signature of heavy-quark decay 10 Oct 2009 66th NuPECC meeting, Egelsbach

66th NuPECC meeting, Egelsbach LHC Schedule Nov 2009: 1st pp collisions very short run at 900 GeV pp collisions at 7 - 10 TeV end of 2010: 3-4 weeks Pb+Pb collisions at 3 - 4 TeV *short technical stop over Christmas period 10 Oct 2009 66th NuPECC meeting, Egelsbach

Some selected key measurements open charm: D0  K +  quarkonia: J/ and trigger 0  , photons from pair-conversions can be addressed in first year of data taking with p+p collisions 10 Oct 2009 66th NuPECC meeting, Egelsbach

Open charm performance Full reconstruction of D0  K + , D*  D0 + + Address heavy-quark production in 1st year of data taking essential input for J/ generation models M (GeV/c2) D* D0 + + ALICE: PPR.vol.II, J. Phys. G 32 (2006) 1295. Simulation: 109 p+p, 108 p+Pb, 107 Pb+Pb collisions 10 Oct 2009 66th NuPECC meeting, Egelsbach

J/ trigger for pp collisions expect some 1k J/ per year in min. bias pp collisions establish single-e and J/ trigger (L1 & L3) allows detailed heavy-quark and jet studies Study J/ suppression / enhancement in Pb+Pb collisions J/ e+e- A. Andronic, P. Braun-Munzinger, K. Redlich, J. Stachel, Phys. Lett. B 652 (2007) 259. 10 Oct 2009 66th NuPECC meeting, Egelsbach

Photon pair-conversions in detector material:  + Z e+ + e- + Z use TPC as pair spectrometer Meaure  yield up to 20 GeV/c with first year pp data access to direct photons  - tagged jets for jet-energy calibration    10 Oct 2009 66th NuPECC meeting, Egelsbach

FOPI experimental program Reference data from elementary reactions K0 ,  production p- + C, Al, Cu, Sn, Pb @ 1.15 GeV/c, K0 , K+, K-, ,  production in p- + LH2, C, Pb @ 1.7 GeV/c, Systematics of strangeness data from hi reactions K0 , K+, K-, , K*, , *(1385) production Search for kaonic bound states System beam energy events Ni + Ni 1.93 AGeV, 100M Al + Al 1.91 AGeV, 200M Ni + Ni 1.91 AGeV, 80M Ni + Pb 1.91 AGeV, 100M Ru+ Ru 1.7 AGeV, 210M Search for exotica in elementary reaction existance of ppK- - bound state p + p 3 GeV, 80M Strangeness: comprehensive system-size scan nearly completed 10 Oct 2009 66th NuPECC meeting, Egelsbach

FOPI III (2008 – 2010) with improved PID K- - PID: S/B > 10 MMRPC TOF Barrel p<0.8 GeV/c 30 supermodules, 150 counters, 4500 electronic channels, 6 m2 active area Performance: system ~ 90 ps RPC ~ 65 ps Worlds best performing multiparticle TOF system so far! Time-of-flight R&D: future technologies for CBM/FAIR Electronics development 10 Oct 2009 66th NuPECC meeting, Egelsbach

Charmed hadrons at FAIR energies Look for statistical hadronization of charm at top FAIR energies c most sensitive ! Need total charm cross section as reference:  measure D-mesons ! total charm energy scan at LHC, RHIC, FAIR  provide input to theory: scales F, R gluon distribution 10 Oct 2009 66th NuPECC meeting, Egelsbach

HD physics program with ALICE Jets and jet-quenching Leading hadron correlations Underlying event correlated with jet-production Heavy-quark tagged jets Photon-tagged jets Photon and neutral meson production Momentum correlations of charged particles Heavy-quark production: open charm and beauty Quarkonia production Collective effects, heavy-quark flow Femtoscopy Diffractive scattering 10 Oct 2009 66th NuPECC meeting, Egelsbach