The PHENIX Muon Trigger Upgrade

Spin 2006 - J. Lajoie 1

The PHENIX Muon Trigger Upgrade

Outline:

A (Brief) Spin Physics MotivationAntiquark Spin Contribution with W+/- bosons

The PHENIX Detector

Muon Trigger UpgradeRequirements, implementation and performance

University of Illinois, Abilene Christian, Iowa State University, UC Riverside, University of Colorado, Nevis Laboratory, Riken-BNL Research Center, University of Kyoto, Georgia State University

John Lajoie – Iowa State University


W

Z

Flavor separation of the spindependent quark and anti-quark distributions in pp collisions @500GeV

GeV 20

for dominates

Tp

W

)0( , ),(

),(

)0( , ),(

),(

2121

21

2121

21

WW

WWL

WW

WWL

yxxMxd

MxdA

yxxMxu

MxuA

Experimental Requirements:

tracking at high pT

good rejection of backgrounds in analysis.

event selection for muons difficult due to background muons from hadron decays and beam backgrounds (timing resolution!).

Parity violation of the weakinteraction in combination withcontrol over the proton spin

orientation gives access to theflavor spin structure in the proton!

For W- interchange

u and d.


• 2 central arms: electrons, photons, hadrons

– charmonium J/, ’ ee

– vector meson ee – high pT

– direct photons– open charm – hadron physics

• 2 muon arms: – “onium” J/, ’, – vector meson – open charmExcellent trigger and DAQcapabilities: multiple trigger signature important for spin

physics can be taken in parallel with high bandwidth!

PHENIX Spin Physics Program: ∆g, ∆q/q, ∆q/q, δq


Trigger Rate and Rejection

HQ signal

momentum dist. At vs=200 GeVDesign Luminosity√s = 500 GeV σ=60mb L = 2x1032/cm2/s

Total X-sec rate ＝ 12MHz

DAQ LIMIT

=1-2kHz （ forμarm ）

Required RF~ 10,000

5025Momentum GeV/c

PT>10GeV/c

PT>20GeV/cW signal

REAL DATA

Need Momentum Selectivity in the LVL-1 Trigger!


PHENIX Muon Trigger Upgrade

R1(a+b)

R2R3

r=100-120cm

r=3.40m

JSPS (Funded)

(II) MuTr front end electronics

Upgrade to allow LL1 information

(I) Three dedicated trigger RPC stations (CMS design):

R1(a,b): ~12mm in , 2 θ pads

R2: ~5.4mm in , 2 θ pads

R3: ~6.0mm in , 2 θ pads

(Trigger only – offline segmentation higher)

NSF (Funded)


Trigger Algorithm

RPC1(a+b)

RPC2

Candidates found by matching RPC1/2 hits within angular range. Momentum cut made by matching hit in MuTr station 2 within three cathode strip2 of RPC projection.

3strip

Simulations (pythia+PISA): RF= 14,000 @ 500 GeV


MuTr FEE Modifications

MuTr Cathode

AMUADC

DCM

GL1BBCLL1

MuIDLL1

CPA

(3 mV/fC)

~1usec

FPGA(MuTrLL1)

PADiscri

Hit pattern

New Board10mV/fC Pseudo-CFD

10:90 Split


MuTr Test Bench@ Kyoto

VDC

VDC

Muon Tracker

Cosmic Ray

Muon Tracker

ASD Test Board

St#1 built with spare parts at UNM

Shipped to Kyoto

PCI readout board from Ecole Polytechnique

m140100-170 22


Resistive Plate Chambers• good timing performance comparable to that of scintillator (~ 1-2 ns)

• space resolution sufficient for muon trigger purpose (~ cm )

• simple design & low cost

• arbitrary readout geometry

• good rate capability (~several kHz/cm2)

RPC’s have been used in L3, BaBar, Belle experiments. All 4 LHC experiments will use RPC for muon system. STAR and PHENIX used MRPC as TOF


RPC Tests (GSU, Colorado, UIUC)

RPC1

RPC2

DC1/2

DC3/4

8.5kV 8.9kV

9.3kV 9.5kV

RPC Cluster Distributions vs. HV (0.5cm strips)


Beam-Background Rejection

• Severity of beam backgrounds at 500GeV (with high luminosity) is largely unknown.

• RPC timing used to eliminate early-time hits.

• Trigger rejection largely independent of beam-related backgrounds.

coming from back (early time hits)

coming from front (in time hits)

R3 R2

R1Collisions!

Beam-Related Background


Physics Timeline

2005 2006 2007 2008 2009 …. 2012 (RHIC II)

10 pb-1 …………………………………… 275pb-1 …….. 950pb-1

√s= ……………………….. 200 GeV …………………......... 500 GeV|

P= 0.5 0.6 0.7 ……………………………………

Inclusive hadrons + Jets ~ 25% Transverse Physics Charm Physics direct photons bottom physics W-physics

ALL(hadrons, Jets) ALL(charm)

ALL(γ) AL(W)

L= 1x1031cm-2s-1 6x1031cm-2s-1 1.6x1032cm-2s-1

see Spin report to DOE http://spin.riken.bnl.gov/rsc/

@ 200GeV @ 500GeV


PHENIX ALW+/- Sensitivity Machine and detector requirements::

– ∫Ldt=800pb-1, P=0.7 at √s=500 GeV

– Muon trigger upgrade!

Expected Sensitivity withW measurement

2009 to 2012 running at √s=500 GeVis projected to yield ∫Ldt ~950pb-1


Summary• The “Spin Crisis” is an opportunity to use spin to probe

the structure of the proton!

• The polarized proton program at RHIC will address two key pieces of information through W+/- production:– The antiquark spin structure functions

• The PHENIX Forward Upgrade will provide the event selection necessary to access this physics:– New RPC-based tracking chambers– New electronics for MuTr LL1 input – New Level-1 Muon Trigger electronics

)(),( xdxu


BACKUP


3 valence quarks + gluons + virtual quark-anti-quark pairs

charge momentum mass spin

?

The Proton

10-15 m

3 valence quarks

charge momentum mass spin

?u

u

d

zLG 2

1

2

1

quark spin

gluon spin

orbital angular mom.

as viewed with a high energy (short wavelength) probeas viewed with a low energy (long wavelength) probe

Using spin we can probe the structure of the proton!

Includes contributions from the quark sea


MuID LL1 Symset Logic

0B

1A

1B

1C

2A

2B

2C

3A

3B

3C

4A

4B

4C

OR OR OR OR

>2

OR

OR

AND deep

• Either gap 0 or gap 1

• Either gap 3 or gap 4

• Three or more hit gaps

• Expected 1D rejection ~500


AGSLINACBOOSTER

Polarized Source

Spin RotatorsPartial Snake

Siberian Snakes

200 MeV Polarimeter

AGS Internal Polarimeter

Rf Dipole

RHIC pC Polarimeters Absolute Polarimeter (H jet)

PHENIX

PHOBOS BRAHMS & PP2PP

STAR

Siberian Snakes

Run 05

AGS pC Polarimeter

Polarized p-p at RHICA New Experimental Method for the

Study of Proton Structure

Helical Partial SnakeStrong Snake

Spin Flipper

1s

2cm

31101~GeV 200

Ls ,

<Pb> = 50%


Generic LL1 Board Design (ISU)

Fiber Bus Termination

Xilinx FPGA Logic

Fiber Transceiver/GLINK

VME Interface

1.8V Regulator

JTAGConnector


Existing MuID LL1 System

20 horizontalfibers

20 verticalfibers

MuID LL1Global Level-1

backplane backplane

blue logic triggers16 bits GL1 data

accepted event data

(4 bits per arm shallow/deep)G

enL

L1

Gen

LL

1

GL1

-2

GL1

-1G

L1-1

P

GL1

-3

40 Gbit/s per arm!

Another quality product from Iowa State University!


LL1 Block Diagram (RPC)• Key issue is to get the MuID LL1 information into

the new LL1’s.

VME crate

Existing MuID LL1 System

40 fibers @ 6xBCLK

New Muon Trigger “LVL1.5”(single board does all)

20 fibers @ 6xBCLK

16-bit backplanebus

56 (48) fibers @ 6xBCLK MuTR20 Fibers @ 6xBCLK RPC

New Muon Trigger “LVL1.5”(each board does two octants)

LL1 Block Diagram (RPC+MuTR)


W+ Production in p + p

Collisions

)0(

),(

),(2

1

21

W

W

WWL

y

Mxu

MxuA

)0(

),(

),(2

1

21

W

W

WWL

y

Mxd

MxdA

Weak interaction violates parity – quark/antiquark helicities fixed!

(left-handed quarks)

(right-handed antiquarks)


Existing MuID Level-1 TriggerLogical tubes formed by OR of physical tubes across panels in each gap.

The most probable trajectory for a vertex muon striking a gap-1 logical tube is to continue on a path of equal dx/dz (vertical tubes) or dy/dz (horizontal tubes). Tubes w/ the same dx/dz (or dy/dz) get the same index.

Rejection Factor ~500 @ 200 GeV/c

The PHENIX Muon Trigger Upgrade

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