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VERTEX 2002 Workshop, Hawaii, November 3-9, 2002 Vertex Detector Upgrade Plans for PHENIX at RHIC Johann M. Heuser RIKEN Radiation Laboratory, Wako, Japan for the PHENIX Collaboration Slide 2 PHENIX Physics Goals Relativistic Heavy Ion Physics: Detection of QGP state of nuclear matter in Au-Au-collisions at s=200 GeV/nucleon. Measurement of its properties. Access leptonic and hadronic probes in the same experiment. Electron pairs, muon pairs, e- coincidences, photons, charged hadrons. Lepton pairs: probe the plasma directly (vector mesons, continuum spectra) Photons: probe the initial phase via prompt (thermal) photons Hadrons: complementary info, hadronization phase transition RHIC I: focus on confirmation of QGP RHIC II: detailed study of QGP Spin Physics: Spin composition of proton. Collisions of polarized proton beams, s=200-500 GeV Main goal: measurement of the gluon polarization. Probes: high-p T photon production, jet and heavy flavor production. VERTEX 2002 Hawaii Johann M. Heuser Slide 3 Slide 4 * tracking: DC, PC1, PC2, PC3 * electron id: RICH, EMC PbSc * photons: EMC PbSc vertex + centrality: ZDC, BBC, MVD * tracking: DC, PC1, TEC, PC3 * hadron + electron id: RICH, TEC, TOF, EMC * photons: EMC PbSc + PbGl Baseline PHENIX Central Spectrometers VERTEX 2002 Hawaii Johann M. Heuser Slide 5 Baseline PHENIX Forward Spectrometers VERTEX 2002 Hawaii Johann M. Heuser Slide 6 PHENIX results & new detector requirements VERTEX 2002 Hawaii Johann M. Heuser One example of recent PHENIX results, presented at QM2002: Electron production from non-photonic sources in min. bias AuAu collisions A detector upgraded beyond the baseline capabilities is required. Upgrades of the vertex region were already foreseen in the PHENIX concept. background subtraction: -- cocktail calculation -- converter method Direct confirmation of charm based sources via measurement of secondary vertices is not possible with baseline PHENIX. In addition, with increasing p T where the beauty contribution becomes a significant or even dominant source of non-photonic electrons, charm/ beauty distinct- ion is needed via secondary vertex reconstruction. Slide 7 Requirements for a new detector 'sub-system': Heavy Ion Program: tracking + electron identification (p T > 200 MeV) over additional tracking at low momenta in field-free region to preserve opening angle of background pairs. secondary vertex reconstruction with r 30-50 m in the central detector and z 200 m in the forward spectrometers. in high-track density environment: dN ch /d 1000 Spin Program: enhanced tracking acceptance precision vertex tracking (heavy flavor decay e and , jet measurement) Upgrade with a Vertex Spectrometer VERTEX 2002 Hawaii Johann M. Heuser one multi-detector Vertex Spectrometer Timeline (vertex tracking): ~ 2005/2006, primarily for spin physics schedule. Slide 8 Upgrade with a Vertex Spectrometer VERTEX 2002 Hawaii Johann M. Heuser +/+ field configuration +/- Slide 9 Vertex Spectrometer VERTEX 2002 Hawaii Johann M. Heuser - Hadron Blind Detector (Cherenkov detector w/o mirrors and windows, gas radiator, CsI photo cathodes + GEM readout chamber). - Time Projection Chamber (HBD radiator as ionizing gas, high drift velocity, multi-stage GEM at end-plates). - Silicon Vertex Detector (4 barrels of pixels and strips, 2 end-caps of 4 pixel disks or cones each). - Flexible field: configuration of outer with new inner magnet coil (installed summer 2002). Slide 10 Silicon Vertex Detector Conceptual Mechanical Specifications Central Barrel layer radius2.5,6,8,10 cm layer length30 cm pixel size50 m x 425 m strips 80 m x 1mm (3cm) pixels( 1 st layer)~1.9M strips(2 nd,3 rd,4 th layer)~165k azimuthal coverage320 deg End Caps (each) inner radius2.5 cm outer radius18 cm disk z pos.(at r in = 2.5cm)20,26,32,38 cm pixel size 50 m x 4 mm total pixels~2.0M azimuthal coverage360 deg VERTEX 2002 Hawaii Johann M. Heuser Slide 11 Silicon Detector Simulated Performance Assumptions: 1% (2%) X/X 0 total per layer; 500 m Be beam pipe. Single tracks / heavy ion events. In Magnetic Field. Barrel: occupancy: (in HI events) 1 st layer