STAR-TOF and Related Physics Outline Introduction Performance of STAR-TOF prototypes Physics results: achieved & expected Summary and outlookJian WU for the STAR Collaboration Department of Modern Physics, USTC

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Introduction Solenoidal Tracker At RHIC (STAR)

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IntroductionWhy STAR-TOF ?Identified hadron spectrafreeze-out dynamicshadronization mechanismIdentified particle correlationsChemical and kinetic properties of in-medium jet associated spectraFluctuations and correlations Lepton programIn-medium vector meson propertiesHeavy flavorBaseline detector for future upgrades TPC dE/dx for low momentum range: /K 0.6 GeV/c proton/meson 1.0 GeV/cTOF will extendmomentum range of PID !

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Introduction STAR-TOF requirement

Good overall timing resolution: < 100 ps in Au+Au collisions.

Small occupancy per channel: < 10%.

Rate capability: 200 Hz/cm2.

High efficiency: > 90%.

Fit into CTB.

Safe and not impair the performance of other STAR detectors

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Introduction STAR TOF groupModule construction and QABNL, LBL, MEPI, NASA, UNAM, RICE, UCLA, UT-Austin, U. Washington, YaleHuazhong Normal University, IHEP(Beijing), IMP(Lanzhou), SINAP, Tsinghua, USTCElectronics, tray assembly, and integration&Project supported by DOE & NSFC

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Performance of STAR-TOF prototypesDesign of Multi-gap Resistive Plate Chamber for TOFrMRPC Strip size3.15cm6.30cmGas gap60.22mmTechnology First developed by ALICE-TOF groupE. Cerron Zeballos et al. Nucl. Instr. Meth. A 374, 132(1996)M.C.S. Williams et al. Nucl. Instr. Meth. A 478, 183(2002)

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Performance of STAR-TOF prototypesTOFr1 Tray Configuration Cover 6 in azimuth and 1 in pseudo-rapidity at radius ~ 2.2m

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Performance of STAR-TOF prototypes Tray Level TOF Electronics (Final)J. Schambach DOE TOF Review

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TDIG

TDIG

TCPU

DATA, CLOCK& CANbus

TINO

TINO

MRPC

MRPC

TDIG

TDIG

96 CHAN

TINO

TINO

MRPC

TRAY CAN BUS

MULTIPLICITY

THUB

COPPER: DATA, SAMPLE CLOCK, RESET TRIGGER STROBE & DATA

TOP LEVEL CAN BUS

COPPER LINKS TO 29 TRAYS

SIU

FIBER

CAN BUS TO 29 TRAYS

TCD

DAQ

96 CHAN

4

L0 Trigger

4

TOF Tray

PMTs

TPMD

TDIG

TCPU

Data, Clock& CANbus

Copper:Data, Sample Clk, ResetTrg Strobe & Data

Start Detector

Reset & ClockFrom other THUBs

Reset & ClockTo other THUBs

To Control PC

L2

MRPC

4

4

SIU

FIBER

Clock & Commands

Busy

Fast Z-Vertex Electronics

PMTs

PMTs

TPMD

TPMD

TDIG

TDIG

3

3

Performance of STAR-TOF prototypesTOFr1 Tray in STAR

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Performance of STAR-TOF prototypes TOF Starter: pseudo-Vertex Position Detector5.4m , 4.43

Performance of STAR-TOF prototypesAchievements from the prototype

86 ps overall timing resolution achieved in 200GeV Au+Au collisions.

3.15 cm 6.30 cm, small granularity

Rate capability: ~300 Hz/cm2 (test beam, CERN)

High efficiency: > 95%

Will benefit from or enhance the performance of other STAR detectors

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Performance of STAR-TOF prototypesTime resolutions in Runs

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Performance of STAR-TOF prototypes Hadron/Electron PID capabilityHadron PID: (, K) ~1.6 GeV/c p ~ 3 GeV/c. STAR Collaboration, PLB616(2005)8Clean electron PID can be obtained up to PT< 3 GeV/c. This has been used to measure the semi-leptonic decay of open charm. STAR Collaboration, PRL94(2005)062301

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Performance of STAR-TOF prototypes Muon identification at low pT0.15

Performance of STAR-TOF prototypes identification powerSTAR Preliminary TOF+TPC : the 2 kaons from are identified using TOF & TPC respectivelyTPC+TPC : the 2 kaons from are identified using only TPC

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Performance of STAR-TOF prototypes PID by combining TOF+TPCTOF alone, (, K) ~1.6 GeV/c , p ~ 3 GeV/c. TOF+dE/dx+rdE/dx ( ,p) 0.3~12 GeV/c M. Shao et al., NIMA 558, (419) 2006

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Physics results achieved Phys. Rev. Lett. 97 152301(2006)

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Physics results achievedIdentified baryon and meson distributions at large transverse momenta from Au+Au collisions at 200 GeV, Phys. Rev. Lett. 97 152301(2006)PID Cronin Effect in d+Au, Phys. Lett. B 616 (2005) 8Charm Cross section and spectra in p+p, d+Au, Phys. Rev. Lett. 94 (2005) 062301A lot of conference proceedings, QM04, SQM04, QM05, SQM06 talks. Two Ph. D theses.

9 NIMA publications: Nucl.Instrum.Meth.A 478:176-179, 2002 (B. Bonner et al) Nucl.Instrum.Meth.A 492:344-350, 2002 (SHao Ming et al) Nucl.Instrum.Meth.A 508:181-184, 2003 (B. Bonner et al) Nucl.Instrum.Meth.A 533:60-64, 2004 (F.Geurts et al) Nucl.Instrum.Meth.A 537:698-702, 2005 (Wang Yi et al) Nucl.Instrum.Meth.A 538:243-248, 2005 (Wu Jian et al) Nucl.Instrum.Meth.A 538:425-430, 2005 (Wang Yi et al) Nucl.Instrum.Meth.A 547:334-341, 2005 (Zhao Yan e et al) Nucl.Instrum.Meth.A 558:419, 2006 (Shao Ming et al)More to come from prototype TOFr

Imagine what we can accomplish with Full TOF (120 trays)

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Physics results expected Physics with Full Barrel TOF - IEvent reduction factor (achieving the same signal statistical significance)

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Physics results expectedPhysics with Full Barrel TOF - IITPC+TOF+SSD+HFT ~ 200M Central AuAu events : 22Kand 6K vector meson pairs for one year RHIC running

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Physics results expected Physics with Full Barrel TOF - III

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Summary and outlook Status & PlansStatusMRPC Standard production procedure setupQuality check measurements definedWeb Parameter Database installed132 MRPCs sent to US already for 4 tray run

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Summary and outlookStatus & plansProduction Facility at Tsinghua (Left) & USTC (Right)

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Summary and outlookStatus & plansTray assembly instruments at UT-AustinG. W. HoffmannDOE TOF Review

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Summary and outlookStatus & plansW.J. Llope DOE TOF ReviewTOFr5 for Runs 5 & 6

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Summary and outlook The advantages of new technology MRPC: good timing resolution, high efficiency , low cost to enable large acceptance etc.

The prototype of TOF detectors in STAR work well, and satisfy the requirements proposed. t ~ 86 ps , efficiency ~ 95%

TOF prototype detectors have already provided important physics results and a full TOF will provide more !

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The End Thanks!

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