Jim Thomas - LBL 1

News about RHIC

with comments about PHOBOS, BRAHMS and the Upgrade Plans for STAR and PHENIX

Jim ThomasLawrence Berkeley National Laboratory

SQM ‘06 @ UCLAMarch 31st, 2006

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BRAHMS

PHOBOS

PHENIX

News from RHIC

RHIC can run at 4.6 GeV – see GSFS

Proposal to retire the Tandem accelerators as the HI injector to RHIC

An EBIS source will take their place

All ions will be possible including U and polarized 3He

Cost of operation will decrease

Operational in 2010

hSTARSTARSTAR

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Luminosity Upgrade with Electron Cooling

Gold collisions (100 GeV/n x 100 GeV/n): w/o e-cooling with e-cooling

Ave. store luminosity [1026 cm-2 s-1] 8 70

Pol. Proton Collision (250 GeV x 250 GeV):

Ave. store luminosity [1032 cm-2 s-1] 1.5 5.0

LinacRf Gun

Buncher Cavity

Cooling Solenoid (26 m, 2-5 T)

Debuncher Cavity

e-Beam Dump

Gold beam

Electron cooling reduces the inter-beam Coulomb scattering and reduces the size of the beam at the IP

Luminosity leveling through continuously adjusted cooling

Store length limited to 4 hours by “burn-off”

First collider accelerator to be limited by beam losses due to interactions that are the subject of study by the experiments

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Two “Small” Detectors at RHIC

BRAHMS2 Spectrometers - fixed target geometryMagnets, Tracking Chambers, TOF, RICH

Inclusive particle production over a large rapidity and pt range

PHOBOS“Table-top” 2 Arm Spectrometer Magnet,

Si -Strips, Si Multiplicity Rings, TOF

Low pt charged hadronsMultiplicity in 4 & Particle Correlations

Ring Counters

Paddle Trigger Counter

Spectrometer

TOF

Octagon+Vertex

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News from PHOBOS and BRAHMS

• PHOBOS has completed its data taking mission– Currently being de-commissioned

– Analysis of data on tape is still on-going; such as flow observables from the Cu-Cu run

• BRAHMS’ data taking mission is nearly complete– Request one brief run with polarized protons at 62 GeV

– Analysis of data on tape is still on-going

Congratulations to the “small” experiments for beautiful

physics measurements over a large rapidity interval.

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STAR Solenoidal field

Large Solid Angle TrackingTPC’s, Si-Vertex Tracking

RICH, EM Cal, TOF

Measurements of Hadronic observables using a large acceptance spectrometer

PHENIXAxial Field

High Resolution & Rates2 Central Arms, 2 Forward Arms TEC, RICH, EM Cal, Si, TOF, -ID

Leptons, Photons, and Hadrons in selected solid angles (especially muons)

News from the “Large” Detectors at RHIC

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Detector Upgrades

• Each detector discovers a different part of the Elephant’s story

• The detector upgrades are designed to complete the coverage of the physics program

– and open new vistas

– the charm and beauty sector … dE/dx, flow, coalescence, NCQ scaling

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• Full Barrel MRPC TOF

• DAQ Upgrade (order of magnitude increase in rate)

• Tracking upgrade:

• High precision Heavy Flavor Tracker near the vertex

• Inner tracker

• End cap tracker for W sign determination

• Forward Meson Spectrometer

STAR Upgrades

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The TOF Upgrade

• Multiplate RPC technology

• Beautiful electron ID

• 85 ps timing resolution after slewing corrections

• Each tray has 72 channels

• 2 full tray this year, with new electronics

• Proposal funded by the DOE

• Construction and install in 2006, 2007, and 2008

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One “tray” (2/60 azimuth, 0<<1)

pK

e

• Doubles the pT range for PID

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TPC FEE and DAQ Upgrade – DAQ 1000

• Faster, smaller, better … ( 10x )

• Current TPC FEE and DAQ limited to 100 Hz

• Replace TPC FEE with next generation CERN based chips … 1 kHz readout

• Make the FEE smaller to provide space for a forward tracking upgrade

• Further improvements by only archiving “associated” clusters – build on L3 algorithms … 5 kHz !

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• Four steps to an order of magnitude increase in data acquisition rates

• TPC FEE (BNL&LBL)

• TPC RDO (BNL)

• DAQ Transmitter (CERN)

• DAQ Receiver (CERN)

Dual CERN D-RORC with fibers on the board

Mezzanine DDL

Single D-RORC with 1 fiber mezzanine

ALICE FEE & DAQ

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• A new detector– 30 m silicon pixels

to yield 10 m space point resolution

– 100 M pixels

• Direct Topological reconstruction of Charm

– Detect charm decays with small c, including D0 K

• New physics– Charm collectivity and

flow to test thermalization at RHIC

– Charm Energy Loss to test pQCD in a hot and dense medium at RHIC

• Desirable to have it in time for the next long Au-Au run

The Heavy Flavor Tracker

The HFT: 2 layers of Si at mid rapidity

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Surround the vertex with Si

A thin detector using 50 m Si to finesse the limitations imposed by MCS

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Inner & Forward Tracking Upgrades

• The IST will add high quality space points to tracks in the TPC

– Si at = 0

• The FST and FGT add high quality space points at forward η

– 1 < η < 2

• High Rate tracking for heavy flavor physics and W production

• Add high quality space points to tracks at high rapidity in the TPC by putting a triple-GEM detector in the gap between the TPC electronics and the EEMC3 layers of Si + 2 layers of GEM at forward rapidity

3 layers of Si at mid rapidity

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Forward Meson Spectrometer Upgrade

• Study forward 0 production at RHIC

( 2.4 < < 4.0 )

• Expand the existing FPD array for forward physics

• 2.4 meter square array of PbGl EMCal modules on the West end

• Use finer segmentation in the middle of the array

• Study vector mesons that decay into 0 and/or photons.

• Installation in ‘06

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L.Bland

3.8 cm inner7.6 cm outer

Side View of the East Pole Tip End View of the PbGl Array~ 2.4 m square, ~ 1500 PMTs

The Forward Meson Spectrometer (detail)

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Timeline for STAR Upgrades

Fiscal Year 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013

MRPC TOF                      

FEE & DAQ Upgrade                      

Heavy Flavor Tracker                      

Inner Tracker                      

End Cap Tracker                      

Forward Meson Spect.                      

Key R&D Construction First Physics Full System

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PHENIX Upgrade Plan

– An aerogel and time-of-flight system to provide complete /K/p separation for momenta up to 10~GeV/c.

– A hadron-blind detector to detect and track electrons near the vertex

– A vertex detector to detect displaced vertices from the decay of mesons containing charm or bottom quarks.

– A muon trigger upgrade to preserve sensitivity at the highest projected RHIC luminosities.

– A forward calorimeter to provide photon+jet studies over a wide kinematic range.

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PHENIX Central Arm Upgrades

• Enhanced Particle ID– TRD (east) – Aerogel/TOF (west)

• Vertex Spectrometer– flexible magnetic field– VTX: silicon barrel vertex tracker– HBD and/or TPC

High pT phenomena: , K, p separation to 10 GeV/c

charm/beauty: TRD e/ above 5 GeV/c

charm/beauty: displaced vertex

e+e- continuum: Dalitz rejection

HBD/TPC

VTXHBD/TPCVTX

TRD

Aerogel/TOF

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Dalitz Rejection: a Hadron Blind Detector

signal electron

partner positronneeded for rejection

Cherenkov blobs

• Dalitz rejection via opening angle – HBD is a proximity focused Cherenkov

detector with ~ 50 cm radiator length

– Provides minimal signals for charged particle

• HBD concept: – Windowless Cherenkov detector

– CF4 as radiator and detector gas

– CsI reflective photocathode

– Triple GEM with pad readout

Bandwidth 6-11eV, N0 ≈ 940cm-1, Npe ≈40No photon feedbackLow granularity, relatively low gain

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Pixel barrel (50 m x 425 m)Strip barrels (80 m x 3 cm)Endcap (extension) (50 m x 2 mm)

1 - 2% X0 per layerbarrel resolution < 50 m endcap resolution < 150 m

Silicon Vertex Tracker (VTX)VTX barrel ||<1.2

Pixel Detectors at R ~ 2.5 & 5 cm Strip Detectors at R ~ 10 & 14 cm Endcap 1.2<||<2.7

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Forward Upgrade Components• Endcap Vertex Tracker

– silicon pixel detectors

• Nosecone EM Calorimeter– W-silicon (20-50 X/X0)

– shower max

– tail catcherCerenkov

NoseconeCalorimeter

U-Tracker

Muon fromhadron decays

Muon from W

TailCatcher

D-Tracker

Silicon endcap

• Muon trigger– U-tracker (MuTr or new)

– D-tracker (timing with RPC’s)

– Cerenkov

charm/beauty & jets: displaced vertex

-jet,W,c: calorimeter

W and quarkonium: improved -trigger rejection

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Nose-Cone Calorimeter• Replace existing PHENIX “nose-cones”

(hadronic absorbers for muon arms) with Si-W calorimeter (Tungsten with Si readout)

• Major increase in acceptance forphoton+jet studies

• Prototype silicon wafer – 3 different versions of

“stri-pixel” detectors for the preshower and shower max layers

• Extended physics reach q/q polarizations via spin

dependent W-production

– Small x-physics in d-A

– Extended A-A program

– high pT phenomena: 0 and -jet

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2002 2003 2004 2005 2006 2007 2008 2009 2010 2011

Aerogel

TOF-W

HBD

VTX-barrel

VTX-endcap

NCC

MuTrigger

DAQ

R&D Phase Construction Phase Ready for Data

PHENIX Upgrades Schedule

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Summary

• The scientific program at RHIC is rich and diverse– Rare probes and high pt phenomena are a rich source of new

discoveries

– Strangeness, Charm, and Beauty are likely to yield even more new discoveries

– We have promising spin program that is making critical and unique measurements

• The scientific program at RHIC will keep getting better– The performance of the accelerator is improving each due to a

carefully planned set of upgrades.

– STAR will explore charm, beauty, and higher pt spectra at ever increasing data acquisition rates.

– PHENIX will add sophisticated PID and tracking near the vertex.

• These upgrades will yield exciting new physics results

The Future is Very Bright