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
Spin 2006 - J. Lajoie 2
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.
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• 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
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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!
Spin 2006 - J. Lajoie 5
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)
Spin 2006 - J. Lajoie 6
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
Spin 2006 - J. Lajoie 7
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
Spin 2006 - J. Lajoie 8
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
Spin 2006 - J. Lajoie 9
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
Spin 2006 - J. Lajoie 10
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)
Spin 2006 - J. Lajoie 11
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
Spin 2006 - J. Lajoie 12
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
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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
Spin 2006 - J. Lajoie 14
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
Spin 2006 - J. Lajoie 15
BACKUP
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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
Spin 2006 - J. Lajoie 17
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
Spin 2006 - J. Lajoie 18
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%
Spin 2006 - J. Lajoie 19
Generic LL1 Board Design (ISU)
Fiber Bus Termination
Xilinx FPGA Logic
Fiber Transceiver/GLINK
VME Interface
1.8V Regulator
JTAGConnector
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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!
Spin 2006 - J. Lajoie 21
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)
Spin 2006 - J. Lajoie 22
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)
Spin 2006 - J. Lajoie 23
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