Spin J. Lajoie1 The PHENIX Muon Trigger Upgrade Outline: A (Brief) Spin Physics Motivation Antiquark Spin Contribution with W +/- bosons The PHENIX Detector Muon Trigger Upgrade Requirements, 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 J. Lajoie2 W Z Flavor separation of the spin dependent quark and anti-quark distributions in pp Experimental Requirements:  tracking at high p T  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 weak interaction in combination with control over the proton spin orientation gives access to the flavor spin structure in the proton! For W - interchange u and d.

Spin J. Lajoie3 2 central arms: electrons, photons, hadrons –charmonium J/ ,  ’  e  e  –vector meson   e  e  –high p T       –direct photons –open charm –hadron physics 2 muon arms: –“onium” J/ ,  ’,      –vector meson      –open charm Excellent trigger and DAQ capabilities: 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

Spin J. Lajoie4 Trigger Rate and Rejection HQ signal  momentum dist. At vs=200 GeV Design Luminosity √s = 500 GeV σ=60mb L = 2x10 32 /cm 2 /s Total X-sec rate ＝ 12MHz DAQ LIMIT =1-2kHz （ forμarm ） Required RF ~ 10, Momentum GeV/c P T >10GeV/c P T >20GeV/c W signal REAL DATA Need Momentum Selectivity in the LVL-1 Trigger!

Spin J. Lajoie5 PHENIX Muon Trigger Upgrade R1(a+b) R2 R3 r= cm 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 J. Lajoie6 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. Simulations (pythia+PISA): RF= 500 GeV

Spin J. Lajoie7 MuTr FEE Modifications MuTr Cathode AMU ADC DCM GL1 BBCLL1 MuIDLL1 CPA (3 mV/fC) ~1usec FPGA (MuTrLL1) PA Discri Hit pattern New Board 10mV/fCPseudo-CFD 10:90 Split

Spin J. Lajoie8 MuTr Test Kyoto 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

Spin J. Lajoie9 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/cm 2 )  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 J. Lajoie10 RPC Tests (GSU, Colorado, UIUC) RPC 1 RPC 2 DC1/2 DC3/4 8.5kV 8.9kV 9.3kV9.5kV RPC Cluster Distributions vs. HV (0.5cm strips)

Spin J. Lajoie11 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) R3R2 R1 Collisions! Beam-Related Background

Spin J. Lajoie12 Physics Timeline … (RHIC II) 10 pb -1 ……………………………………  275pb -1 …….. 950pb -1 √s= ……………………… GeV ………………… GeV| P= …………………………………… Inclusive hadrons + Jets ~ 25% Transverse Physics Charm Physics direct photons bottom physics W-physics A LL (hadrons, Jets)A LL (charm) A LL (γ) AL(W)AL(W) L= 1x10 31 cm -2 s -1 6x10 31 cm -2 s x10 32 cm -2 s -1 see Spin report to DOE 500GeV

Spin J. Lajoie13 PHENIX A L W +/- Sensitivity :  Machine and detector requirements: – ∫Ldt=800pb -1, P=0.7 at √s=500 GeV – Muon trigger upgrade! Expected Sensitivity with W measurement 2009 to 2012 running at √s=500 GeV is projected to yield ∫Ldt ~950pb -1

Spin J. Lajoie14 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

Spin J. Lajoie15 BACKUP

Spin J. Lajoie16 3 valence quarks + gluons + virtual quark-anti-quark pairs charge momentum mass spin ? The Proton m 3 valence quarks  charge momentum mass spin ? u u d 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 J. Lajoie17 MuID LL1 Symset Logic 0B 1A 1B 1C 2A 2B 2C 3A 3B 3C 4A 4B 4C OR  >2 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 J. Lajoie18 AGS LINAC BOOSTER Polarized Source Spin Rotators Partial Snake Siberian Snakes 200 MeV Polarimeter AGS Internal Polarimeter Rf Dipole RHIC pC Polarimeters Absolute Polarimeter (H jet) P HENIX P HOBOS B RAHMS & PP2PP S TAR Siberian Snakes Run 05 AGS pC Polarimeter Polarized p-p at RHIC A New Experimental Method for the Study of Proton Structure Helical Partial Snake Strong Snake Spin Flipper = 50%

Spin J. Lajoie19 Generic LL1 Board Design (ISU) Fiber Bus Termination Xilinx FPGA Logic Fiber Transceiver/GLINK VME Interface 1.8V Regulator JTAG Connector

Spin J. Lajoie20 Existing MuID LL1 System 20 horizontal fibers 20 vertical fibers MuID LL1 Global Level-1 backplane blue logic triggers 16 bits GL1 data accepted event data (4 bits per arm shallow/deep) GenLL1 GL1-2 GL1-1 GL1-1P GL Gbit/s per arm! Another quality product from Iowa State University!

Spin J. Lajoie21 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 6xBCLK New Muon Trigger “LVL1.5” (single board does all) 20 6xBCLK 16-bit backplane bus 56 (48) 6xBCLK MuTR 20 6xBCLK RPC New Muon Trigger “LVL1.5” (each board does two octants) LL1 Block Diagram (RPC+MuTR)

Spin J. Lajoie22 W + Production in p + p Collisions Weak interaction violates parity – quark/antiquark helicities fixed! (left-handed quarks) (right-handed antiquarks)

Spin J. Lajoie23 Existing MuID Level-1 Trigger Logical 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 200 GeV/c