ALICE LHC l ALICE Status Detector Performance cosmics

ALICE @ LHC l ALICE Status ð Detector ð Performance (cosmics) ð commissioning: S. Chaplain l Early Physics Program ð first physics: JF Grosse Oetringhaus (Thursday) ð HI parallel talks Friday pm Sept 2008 Split J. Schukraft First interaction in ALICE: 11. 9. 2008 (beam – pixel collisions) 1

ALICE Collaboration ~ 1000 Members (63% from CERN MS) ~30 Countries ~100 Institutes ~ 150 MCHF capital cost (+ ‘free’ magnet) A brief history of ALICE 1990 -1996: 1992 -2002: 2000 -2010: 2002 -2007: 2008 -> : 2 Design R&D Construction Installation Commissioning Oct 2008 Split J. Schukraft

Size: 16 x 26 meters Weight: 10, 000 tons Detectors: 18 3

4 Formal end of ALICE installation: July 2008 Oct 2008 Split J. Schukraft

The ALICE Magnet in 2000: ready for the experiment to move in! 5

TPC l largest ever ð 88 m 3, l = 5 m, d = 5. 6 m 570 k channels l novel features ð lightweight, cool drift gas powerful FEE drift gas Ne - CO 2 – N 2 (86/9/5) FEE HV membrane (25 mm) 6 Oct 2008 Split J. Schukraft

First TPC Tracks 16 May 2006 First cosmic and laser tracks ! 7 Oct 2008 Split J. Schukraft

Position Monitor TPC Installation (January 2007) 8 < 100 m horizontal, < 100 m vertical in 2 days <v> = 4 m/hour

TPC Commissioning with Cosmics Cosmic induced shower Cosmic through TPC & ITS SPD trigger 9 Oct 2008 Split J. Schukraft

TPC Performance l First preliminary results (cosmics) ð excellent noise performance (s ~ 800 e) ð d. E/dx resolution (goal: ~ 5. 5%) µ < 6% (gain calibration with Krypton) ð pt resolution (PPR goal: ~ 5% @ 10 Ge. V) µ ~ 10% @ 10 Ge. V w/o calibration Momentum Resolution (uncalibrated) Particle Identification 10 Oct 2008 Split J. Schukraft

Inner Tracking System ~ 10 m 2 Si detectors, 6 layers Pixels, Drift, double sided Strips 3. 9 cm < r < 43 cm Pixels Drift 11 Strips Oct 2008 Split J. Schukraft

ITS Installation 15. 3. 07 12

13 After 6 months of cabling: Moving TPC over ITS (September 2007)

Tracking l robust, redundant tracking from 100 Me. V to 100 Ge. V ð modest soleniodal field (0. 5 T) => easy pattern recognition ð long lever arm => good momentum resolution (BL 2 : Alice ~ CMS > Atlas !) ð small material budget: ~ 10% X 0 vertex -> end of TPC (r = 2. 6 m) l full GEANT simulation: central Pb-Pb, d. Nch/dy = 6000 ð very little dependence on d. Nch/dy up to 8000 (important for systematics !) Impact parameter < 50 mm for pt > 1. 5 Ge. V Momentum resolution ~ 5% @ 100 Ge. V 14 Oct 2008 Split J. Schukraft

ITS: fully installed & commissioned SSD: charge correlation p-side vers. n-side SSD: S/N ~ 40 SPD Alignment: impact resolution s ~56 mm misalignment < 10 mm !! after alignment before alignment Drift speed for hours SDD: Drift constant speed calibration & monitoring versus time 15 Oct 2008 Split J. Schukraft

Particle Identification l stable hadrons (p, K, p): ð d. E/dx in silicon (ITS) and gas (TPC) + Time-of-Flight (TOF) + Cerenkov (HMPID) l leptons (e, m) ð transition radiation (TRD), muon spectrometer l photons, h, p 0 ð e. m calorimeters (PHOS, EMCAL) l decay topology (K 0, K+, K-, L, D+, . . ), secondary vertices (c, b) PID from ~ 100 Me. V to above 50 Ge. V Alice uses ~ all known techniques! 16 Oct 2008 Split J. Schukraft

Time of Flight ~ 140 m 2 Multi. Gap glass RPCs, > 150 k TOF channels, s < 100 ps PID up to 2. 5 (p/K) – 4 (K/p) Ge. V 17 TOF Supermodule (#18) (April ’ 08) Last Oct 2008 Split J. Schukraft

TOF status l Fully installed, 2/3 commissioned ð L 0 TOF trigger fully functional, noise rate factor 2 better than expected ! ð refurbishing of DC-DC converters not quite finished TOF cosmic trigger 18 TOF raw spectra (no calib/slewing, offset correction etc. . ) Oct 2008 Split J. Schukraft

Transition Radiation Detector added 2000: 6 layer, fiber radiator, 715 m 2 drift chambers, r > 3 m L 1 (6. 5 ms) tracking & trigger capability Status 4/18 modules installed (problems with gas tightness being resolved) detector & trigger commissioned From Pit Test beam 19 TRD supermodul Oct ’ 06 First Time bin (100 ns/bin) Oct 2008 Split J. Schukraft

High Momentum PID ~ 11 m 2 prox. focusing RICH detector Cs. I photo-cathode, MWPC chambers PID up to 3 (p/K) – 5 (K/p) Ge. V 20 Installation: September ’ 06 Oct 2008 Split J. Schukraft

HMPID during LHC beam dump online display 3. 9. 2008 TPC-HMPID track matching (w/o alignment) HMPID cosmic event 21 Oct 2008 Split J. Schukraft

PHOton Spectrometer l Status: 3/5 constructed ð 2 more modules to be constructed µ funding stretched to 2010 ð only 1 installed & commissioned µ condensation => improve insulation ~ 8 m 2 Pb. W 04 crystals, r ~ 5 m 18 k channels, 20 X 0 APD R/O high 22 resolution & granularity Module 1 installed mid ‘ 08 Oct 2008 Split J. Schukraft

Electromagnetic Jet Calorimeter l Construction start April 2008 ð approved & funded Dec 2008 µ US, Italy, France, Finland ð ~ 20% to be installed early 2009 µ complete early 2010 44 m 2 Pb-Scint sampling calo, 20 X 0, 13 k FEE APD R/O |h|<0. 7 Df = 110 o r = 4. 4 m 23 Nov 2007: Oct EMCAL 2008 Split J. support Schukraft

Muon Spectrometer 24 10 CSC tracking planes, 90 m 2, 1. 1 M FEE 4 RPC trigger planes, 120 m 2, 20 k FEE Dipole 0. 7 T, 3 Tm Acceptance 2. 4 < h < 4 s(M): 70 Me. V (J/Y) – 100 Oct. Me. V(Y) 2008 Split J. Schukraft

25 Installation of last muon chamber May 2008

Muon Arm Status Muon tracking: Muon trigger; ~ 70% commissioned fully operational A rare ‘vertical’ cosmic, pointing to the IP 26 Christophe. Suire@ipno. in 2 p 3. fr Oct 2008 Split J. Schukraft

Forward Detectors PMD Pre-shower detector 2. 3 < h < 3. 5, Ncharged and Nphotons V 0 1. 6 < |h| < 3. 9 Interaction trigger Two arrays of 64 scintillator tiles readout via fibers and PMT’s T 0 A FMD: Multiplicity & d. N/dh 1. 6 < h < 3, -5. 4 < h < -1. 6 T 0 C: 2. 6 < |h| < 3. 3 Time (T 0) 3 Silicon strip disks , 12 k FEE (~ 50 ps time res. ) Two arrays of 12 quartz counters. 27 ZDC: Centrality, 2 sets of Zero Degree Calorimeters, > 100 m inside LHC tunnel, 2 small em calorimeters Oct 2008 Split J. Schukraft

ZDC T 0 C PMD ZN ZP V 0 A FMD 3 28

Online l Continuous online operation since March (24/7) ð DAQ: 40% HW installed, stable operation up to 500 MB/s transfer, rates > 3 k. Hz ð DCS/ECS: essential functionality operational, continuous improvement µ some problems encountered with scalability (mostly resolved) ð CTP: some problems with spurious triggers resolved, running well ð HLT: 500 CPU’s, very successful operation (online reconstruction, data reduction) Aggregated cumulative time in the global partition 29 24/9/2008 LHCC Status Report J. Schukra

Early Physics Program l Physics of the first ‘year’… ð ‘day 1’ physics with pp: global event properties (0. 9/10/14 Te. V ? ) µ requiring only subset of detectors, few 10, 000 events ð‘ early pp physics’ detailed studies of pp ð first heavy ion run 30 ‘at the end of the first long pp run’ 24/9/2008 LHCC Status Report J. Schukra

QCD at 14 Te. V l ALICE physics with pp ð Taking ‘comparison data’ for the heavy ion program µ eg: J/Y suppression in AA requires measuring J/Y production in pp ð Survey and characterization of typical (‘Minimum Bias’) events µ multiplicity, pt distribution, particle composition, …. µ => tuning of Monte Carlo generators (which differ widely) µ => evaluate background & detect. performance Gluon junction ð Specific QCD measurements for which ALICE is particularly well suited µ signals involving PID eg ‘baryon transport: how are the beam protons decelerated’ µ low x-physics, charm & beauty production at low pt , … D 0 -> Kp acceptance down to 0 pt Optimization of pixel trigger thresholds to reach multiplicities > 10 -20 x average L*(1520) -> p. K 31 24/9/2008 LHCC Status Report J. Schukra

The Particle Zoo l comprehensive survey ð list still expanding µ h, D*, D+-, …. . ð main topic for heavy ions: µ T, m, flow, recombination, HBT, . . ð fully characterize MB pp µ in a depth not seen since ISR 32 Oct 2008 Split J. Schukraft

Summary l Installation: ð met all installation goals by mid 2008 ð construction & installation not finished in ALICE (continuously upgrading !) µ PMD (2008), DAQ/HLT(2009), TRD (2009), PHOS (2010/11), EMCAL (2010/11) l Commissioning and initial calibration/alignment ð went rather well, sometimes even better than expected µ some (mostly minor) hickups / problems (noise, lost channels) / bug fixing l Detector performance ð better – within - very close to specs (at least as far as could be verified with cosmics and LHC injection tests) 33 Oct 2008 Split J. Schukraft