1. Silicon Verterx Tracker Upgrade of PHENIX Experiment at RHIC Y. Akiba (RIKEN) CIPANP2003 New York, New York May 2003

2. l West Arm l tracking: DC,PC1, PC2, PC3 l electron ID: RICH, EMCal l photons: EMCal l East Arm l tracking: DC, PC1, TEC, PC3 l electron & hadron ID: RICH,TEC/TRD, TOF, EMCal l photons: EMCal PHENIX Setup Completed in 2003 l South & North Arm l tracking: MuTr l muon ID: MuID l Other Detectors l Vertex & centrality: ZDC, BBC, MVD l Beyond Baseline l TRD upgrade l FCAL

3. Physics Beyond Reach of Current PHENIX l Detailed study of Heavy Quark production l Beauty measurement in Au+Au collisions l Energy loss of charm/beauty in hot matter G measurement by heavy quark production in wide x range l Gluon shadowing in wide x range Measurements complement and enhance the present physics program fully exploit existing rare event capabilities of PHENIX PHENIX central and muon spectrometer are essential Provide key measurements so far inaccessible at PHENIX:

4. Open Charm and Beauty l Physics interest in charm and beauty in Heavy Ion Collisions l Do heavy quarks lose energy in quark matter? l charm can be produced thermally charm enhancement critical base line for J/ and Y production & dilepton continuum l Spin Physics with charm/beauty l Gluon polarization in wide l PHENIX measured charm via inclusive electron (PRL88 (2002) 192303) l Indirect measurement l can not distinguish charm and beauty for p T > 4 GeV/c beauty charm Charm and beauty separation aim of future PHENIX program

5. Detection of decay vertex will allow a clean identifications of charm and bottom decays m c GeV m D 0 1865 125 D ± 1869 317 B 0 5279 464 B ± 5279 496 Need secondary vertex resolution < 50 m Beauty and high p T charm will require high luminosity Direct Observation of Open Charm and Beauty Detection options: Beauty and low p T charm through displaced e and/or Beauty via displaced J/ High p T charm through D K Au e D D X J/ B X K Central arm & barrel SVT muon arm & end cap SVT

6. Pixel barrels (50 m x 425 m) Strip barrels (80 m x 3 cm) Pixel disks (50 m x 2 mm) ~1.0% X 0 per layer barrel resolution < 50 m forward resolution < 150 m 1.2<| |< 2.4 | |< 1.2 Silicon Vertex Tracker in PHENIX Strawman design under investigation

7. Charm/Beauty measurements with the barrel SVT lb e by barrel+central arm c HIJING Au+Au l In Au+Au l Robust charm measurement at low pt l Beauty measurement l Direct charm measurement at high pt Clear c/b separation Energy loss of charm at high pt l Direct measurement of charmed hadron with central arm + barrel lc e by barrel+central arm

8. l Single muons associated with end-cap Charm/beauty measurement with SVT end-cap Without SVT, most muons are from decay of, K After muon tracks are associated with the endcap SVT, muon spectrum is dominated by charm decay z vertex (cm) direct J/ J/ from B Beauty J/ in endcap + muon arm B decays to J/ with about 1% branching ratio With the end-cap SVT, direct J/ and J/ from B decay can be clearly separated.

9. Spin Physics with SVT Upgrade l Measurement of Gluon polarization by Heavy flavor production c, b e, + displaced vertex B displaced J/ D K at high pt l SVT measurement of displaced vertex Improved S/B higher sensitivity to G(x) Much broader x-range coverage SVT significantly increases the x converage of G(x) measurement

10. Measurement of gluon shadowing with SVT l Heavy-flavor measurement in p+A Single lepton and J/ with displaced vertex l Heavy-flavor production via g+g q+ q l Extracting gluon structure function nuclei, shadowing l vertex detector provides broader range in x into predicted shadowing region (x ~ 10 -2 - 10 -3 )

11. Silicon Vertex Tracker R&D l Ongoing R&D l Silicon strip sensor development l Hybrid pixels (with ALICE and NA60) l design of support structure l Critical contributions supported by R&D proposal l silicon strip readout & integration into PHENIX l hybrid pixel integration, thinning & bump bonding l development of monolithic active pixel sensors l design of support structure including cooling etc l Participating institutions l BNL, ISU, Kyoto U., LANL, ORNL, RIKEN, Stony Brook U. Hit map x x u u strip sensor design Z.li, BNL strip sensor test RIKEN NA60 hybrid pixel tests (RIKEN,SB)

12. Silicon Vertex Tracker R&D Beam test at KEK by RIKEN/Kyoto =52 =35 =45 =35 =49 Source test at RIKEN

13. Year FY03 FY04FY05 FY06 FY07FY08FY09 Silicon barrel forward silicon DAQ/Trigger R&D construction Silicon barrel forward silicon DAQ/Trigger Upgrade Physics Program Heavy flavor Enhanced G/G p-nucleus program Time Line for PHENIX Upgrades

14. Summary l Goal: l Detailed study of Heavy Quark production in pp, pA (dA), and AA collisions at RHIC l Physics with SVTX upgrade l Au+Au Energy loss of charm at high pt Beauty production l Polarized p+p G(x) measurement in wide x range (polarized proton) l p+A (d+A) Gluon shadowing in wide x range l Proposed Sillicon vertex detector l Si barrel (1 pixel + 3 strips) l Si end cap l R&D