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Triggering on Electromagnetic Objects (e  / ) at L1 & L2 Mrinmoy Bhattacharjee

Triggering on Electromagnetic Objects (e  / ) at L1 & L2 Mrinmoy Bhattacharjee SUNY, Stony Brook D0 EM ID Vertical Review Thanks to: Arnaud Lucotte, Kin Yip, Paul Grannis,

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Triggering on Electromagnetic Objects (e  / ) at L1 & L2 Mrinmoy Bhattacharjee

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  1. Triggering on Electromagnetic Objects • (e/) • at L1 & L2 • Mrinmoy Bhattacharjee • SUNY, Stony Brook • D0 EM ID Vertical Review • Thanks to: • Arnaud Lucotte, Kin Yip, Paul Grannis, • Manuel Martin, Levan Babukhadia, • Marc Buehler, Dave Toback, Dylan Casey

  2. Overview • Motivation • D0 Trigger system (L1 & L2) • L1 EM Trigger: • Detector information at L1 • High pT EM trigger & low pT di-electrons •  Algorithm • * Timing •  Efficiencies & Rates • L2 EM Trigger: • Detector information at L2 • High pT EM trigger & low pT di-electrons •  Algorithm • * Timing •  Efficiencies & Rates • Summary

  3. Motivation • Run II peak inst.lum. 2  1032cm2s-1 • Total accumulated data 2 fb-1 • Measurements with High PT e/ • Mt < 3.0 GeV/c2 •  ttbar/ttbar ~ 10% • anomalous properties of top • ( = 8.0pb/4.2pb pptt+X /ppt or t+X) •  Mw ~ 40MeV/c2 •  sin2W from Z asymmetry •  pdf from W asymmetry • fwd e-’s improve MW systematic (RunI) • (1.6106 W  e / 160 103 Z  ee) •  QCD with WZ •  qqbar  W & WW • trilinear couplings & • radiation zero effect •  SUSY searches

  4. Motivation • B Physics with electrons •   bbar ~ 100 b •  CP violation in Bd  J/Ks system •  Bs mixing •  Rare B decays •  Measurements on Bc meson • Low pT e-/ from ,  & Drell Yan • Accumulate large samples of e/ • High signal efficiency/background rejection • Possible with (trk - energy) matching •  Calorimeter (energy threshold) •  CFT, CPS, FPS & SMT (tracking)

  5. L1 & L2 Trigger Configuration • Level 1 Level 2 • F • E • L1 Accept • Expect 128 Trigger Termsto go to 256 Input7MHz output 7KHz time 4.2s Input 7KHz output 1KHz time 100s 5% dead time Silicon L2 STT CFT Ax L2 CTT L1CFT, CPS CPS Ax L2 CPS L2 GlobalCal+PS+CFT FORM 128 TriggerTerms CPS St FPS L1 FPS L2 FPS CAL L1 CAL L2 CAL Muon L1 Muo L2 Muo L1 Trigger Framework combine EM Tower, track/cluster FORM 128 TriggerTerms

  6. Challenges • Major Challenge: • Input Rate to L1 ~ 7.6MHz at 1032cm-2s-1 • <pT> e- for J/ee- <pT> e- for W,Z top ~ 2.7 GeV/c central decays • ~ 3.1 GeV/c forward ~ 30-40GeV/c • Low threshold in CAL Although threshold high •  high QCD rate S/B ~ 1/50,000

  7. Definition of EM object (e-/) • e = CFT trk + CPS cluster • + CCEM Trigger Tower •  = No Trk + CPS cluster • + CCEM Trigger Tower • e = MIP + FPS clust • + ECEM Trigger Tower •  = No MIP + FPS cluster • + ECEM Trigger Tower Central Region Forward Region

  8. L1: Tracking with CFT • Inner most tracking device at L1 is CFT (||1.5) • CFT divided into 80 sectors 4.5o wide • Fibers shared between nearest sectors • to allow for bending in magnetic field • Tracking Algorithm at Digital FE (FPGAs) •  Allowed trajectories computed analytically for • pT>1.5GeV/c (equations) •  Match hit patterns in all 8 layers with • pre-programmed equations (anchor on H layer) Sector boundary Track H CFT Sector 1 A CFT Sector 2

  9. L1: CFT Tracking (# of eqns, binning) • Neqn 1/pT per sector ( 16K eqns) • Tracks binned in pT • pT binning gives sharper turn on than offset binning • [1.5-3.0], [3.0-5.0], [5.0-10.0], [10]Gev/c

  10. L1: Energy Clustering with CPS & FPS • CPS next on path of EM particle (||1.5) • 3 layers of nested triangular strips (1280/layer) • 1 Axial Layer, strips || to z-axis • 2 Stereo Layers, strips at ~ 230 • Preceded by Solenoid & 1X0 Pb (2X0) • CPS divided into 80 sectors 4.5o wide (same as CFT) • At L1 only Axial strips used • FPS available at L1 in 1.6||2.5 • FPS divided into N/S, each side 16  sectors • 4 Layers of nested triangular strips & 2X0 Pb • 2 layers infront (MIP) of Pb; 2 behind (shower) • layers has strips making 22.50 (U & V) • MIP deposition front of Pb coincident with EM shower behind used to trigger on e-/

  11. L1: Cluster Finding ||<1.5 (CPS) • Clustering Algorithm at Digital FE (FPGAs) • Contiguous strips > Threshold forms a clusters • Two separate thresholds used for clustering • 2-5 MIPs (low) for low pT electrons (J/ee) • 5-10 MIPs (high) for high pT electrons (W,Z,top) • Only Axial strips used for L1 triggering • xxLLHLxx is one 1 high cluster (NOT 2 lows & 1 high) • Number of clusters/layer • These are input to L2 3 MIPs 5 MIPs

  12. L1: Cluster Finding 1.6<||<2.6 (FPS) • Clustering Algorithm at Digital FE (FPGAs) • Contiguous strips > Threshold forms a clusters • Two separate thresholds used for clustering • 3-5 MIPs (low) for low pT electrons (J/ee) • 5-10 MIPs (high) for high pT electrons (W,Z,top) • Cluster confirmed by MIP deposition (0.3MIPs) • 7 strip wide window centered at cluster center & • detector origin • Number of shower clusters/layer • These are input to L2 3 MIPs 5 MIPs

  13. L1: From DFE to L1 CFT/CPS, FPS & L2 • Info sent to L1 CFT/CPS • —# of () tracks per pT bin with hi/low/NO CPS axial tag • — # of isolated tracks & pT of all tracks • Info sent to L1 FPS • —# of U/V clusters (hi/low) with/without MIP hit • Info sent to CFT L2 • — list of 6 tracks per pT (46 max per quadrant) • Low pT (3GeV/c): H layer hit & (A-H) offset reported • High pT (3GeV/c): H layer hit & pT reported • Track ALSO matched to hi/low CPS Axial cluster • Info sent to CPS L2 • — From CPS Axial (48 max per Quadrants) • Axial cluster list with address and width (high & low) • Axial clusters matched to (±) CFT tracks in 3 strips • Track pT if present • — For CPS Stereo(48 max per N/S U/V) • Stereo cluster list with address & width (high & low) • Info sent to L2 FPS(48 max per N/S U/V) • —Stereo cluster list with address and width (high & low) • w/o MIP hit (48 max per quadrant)

  14. L1: Tracking & Clustering efficiency • CFT alone • efficiency 90% • FPS alone • efficiency 98% • rejection e/ 3

  15. L1: Calorimeter • Task Performed at L1 (Preamps & Analog ) • Trigger towers (TT) are 0.20.2 in  • TTs > 2.5, 5, 7 & 10GeV used as seed • L1 EM ET rounded in 0.25GeV steps • L1 Total ET truncated in 0.5GeV steps • Information available at L1 • (1) For each ref set   TT’s > Threshold (all ) • (2) EM ET /  Had ET in Large Tile Area (LTA) • (1 LTA = 8 TT’s in  & 4 TT’s in ) • (3) Number of TT’s above threshold in LTA • # TT’s > threshold for each Ref set can be made available for Quadrants • (1 Quadrant = 4 TT’s in  & 8 TT’s in ) • Send 64 AND/OR terms to L1 Framework

  16. L1: Trigger Terms • Trigger information from different detectors are sent to the Trigger Framework to be matched & final trigger decision • EM Trigger Terms • TTK(n,p): CFT track pT > p. • TEL(n,p): CPS cluster/CFT track pT(>p) match within 4.50. • TPQ(n,q): CPS cluster/CFT track (>lo/1.5Gev) match by quad. • TNQ(n,q): CPS cluster (>lo) by quadrant (no track = EM). • TDL(p,s): 2 trk/CPS cand. (pT>1.5 or 5GeV), same/opp sign • FPQ(n): FPS cluster/CAL tower(>2.5GeV) match by quad. • FQN/S(n): FPS cluster/CAL tower (>2.5GeV) match by quadrant (e+). • CEM(n,E): Cal EM tower (>2.5,5.7,10GeV) in CC or EC. • CEQ(n,q): CPS cluster/CAL Tower (>2.5GeV) match by quad q. • CER(n,E,): 1/2 CAL EM tower >2.5/5GeV in N,S,CC

  17. L1 electron algorithm (high pT) • Central (1.6) • 1 CPS cluster  high matched to 1 track 5GeV/c in 4.50 • 1 Calorimeter EM tower  7-10GeV (1.6) matched to CPS cluster by quadrant • Forward (1.62.6) • 1 FPS cluster  high + MIP confirmation • 1 Calorimeter EM tower  7-10GeV (1.62.6) matched to FPS cluster by quadrant • Track/MIP matching to PS optional; perform only if rates high ||1.0 1.6  ||2.6 Cal EM >7GeV

  18. L1 EM trigger rates (high pT) • Rates at L=21032cm2/s • Cluster/Track & CCAL Quadrant match • Cluster & ECAL Quadrant match • CEM(1,10,C) 200 W mass, QCD  • CEM(1,7,C)CEQ(1)TNQ(1) 62 QCD  • CEM(1,10,C)TEL(1,5) 3 W mass, WZ  • CEM(1,10,N/S) 690 EC W mass • CEM(1,10,N/S)FQN(1) 400 FWD EM • CEM(1,10,N/S)FPQ(1) 200 EC W mass • Rates highly dependent on thresholds in CAL • Quadrant matching give 2-4 in rates rejection ||1.0

  19. L1 Trigger timing issues • FE is 32 deep pipe line • L1 Trigger: • L1 decision conveyed to AFE in ~25 crossings • Upon L1 accept AFE/DFE send L2 data • 4.8s deadtime due to SVX readout & empty pipeline • Readout to L2: • Have to be completed within 36 crossings (4.8 s)

  20. L2 EM Trigger • Advantages at L2 are: • (1) Large decision time 100sec • (2) Finer detector information available • -- clustering in PS • -- clustering in CAL • (3) Due to more time finer matching can be • performed • -- L1 CAL/PS matching in quadrant • -- L2 CAL/PS match within 0.20.2 • in 

  21. L2: CAL Preprocessor • L1 EM Trigger based on following reference set • 2.5, 5, 7 & 10 GeV ET • (1) L2 uses TT’s above low threshold ref. set • (2) Find 2nd. Maximum in 33 around seed • (3) ETEM = ETEMseed + ET2nd > Thr • (4) EMF = ETEM/(ETEM+ETHAD) • (5) TISO =  ET(EM+Had)/ETEM( 33  - seed ) • =ETEM/ET(EM+HAD) (33  includes seed) • Both EMF & Isolation useful in background rejection

  22. L2: CAL Efficiency, Rates & Timing • (In 1.62.6) • L1 seed tower 7GeV / 10GeV • ETEM  10GeV / 12GeV • EMF  0.85 • TISO  0.4 • pT 15Gev/c 20GeV/c 32.5GeV/c • L2/L1 93.3% 99.5% 100.0% • “ 86.0% 100.0% 100.0% • Dijet Rates • L1(1,7GeV) L2(1,10GeV) L2(1,12GeV) • @2E32 900Hz 145Hz 90Hz • L2 CAL Timing(available 50sec) • L2Seed cut 0.5GeV 1.0GeV 1.5GeV 2.0GeV • # of seeds 77 19 10 7 • Time s 179 46 25 18

  23. L2: CPS Preprocessor • At L2, CPS provides 3D point combining X,U,V • Input to L2PP • Axial = cluster address, width & threshold (h/L), • tracks pT if present • Stereo = cluster address, width & threshold (H/L) • Algorithm • Hit U,V  Xuv (</=1280) & Zuv (±125cm) • Xuv -True X within ±10 Strips (0.05 in ) • Calculate  from parameterization vs. Zuv (0.004 in ) • Calculate  from Axial hit strip • Bin CPS , into 0.250.25 for CAL matching at L2 Global • OUTPUTS of L2 CPS: • HEADER: Cluster Count • DATA: Cluster  bin, • Cluster  bin, HiLo, Track Tag

  24. L2: FPS Preprocessor • At L2, FPS provides 3D point combining U & V • Input to L2PP • Stereo =cluster address, width & threshold (H/L), MIP bits • Algorithm •  parameterized as hit U + V •  parameterized as hit U - V • Confirm  as valid (within FPS detector) • Bin FPS , into 0.25*0.25 for CAL matching at L2 Global • OUTPUT of L2 FPS: • HEADER: Cluster Count • DATA: Cluster  bin, Cluster  bin, • HiLo, MIP Bit pattern

  25. L2: Preshower Timing 3MIPs 5MIPs • Available 50sec • Timing  number of clusters • CPS Low threshold ~ 90% in 40sec (500Hz devoted) • FPS Low threshold ~ 95% in 24sec (500Hz devoted) CPS FPS

  26. L2: STT & CTT Preprocessor • No STT: • L1CFT to L2CTT (Quadrants) • Converts L1 pT information to track pT (lookup table) • Extrapolates H layer  to EM3 • Merge track lists & order in pT & convert to L2 objectSend info to L2Global upto 184 tracks • With STT: • L1CFT to STT sextant boards • 48 tracks per sextant • covers 60o in  & overlap region allow for track bending • ordered in pT bin • Sextant boards to L2STT • 46 tracks per sextant • Matches CTT tracks to SMT clusters and refit • get track pT ,, dE/dX & b • send tracks to L2CTT in 12 cables 30o in  • L2STT send tracks to L2CTT • Merge 12 track lists pT • Merge 12 track lists & order in b • Send tracks to L2Global upto 184 tracks

  27. L2: CTT Timing • L2 Preprocessor Time depends on # of tracks • Time taken to make L2 objects, sort them in pT • & output them to L2Glb • Ntrk 0 1 2 4 8 16 32 64 • Time(s) 0.8 1.3 1.9 3.1 5.7 11.8 27.8 78.8 • Study performed on 233MHz board • Alpha timing 1.6 factor better

  28. L2 electron algorithm (high pT) • Central (1.6) (L2 Global 50sec) • 1 CAL tower 7GeV • 1 CPS Axial cluster  5MIPs + CFT Track tag • CPS 3D match of X,U,V ,  • (1) Axial ,U, V = 5MIPs • (2) Axial = 5MIPs & U,V = 3MIPs • Different detector info combined at L2 Global • CPS-CAL match within 0.250.25 in  • (Z  ee, 93.7%) • (1) efficiency loss for ET <40GeV(W+Jets, 84.0%) • (Z  ee, 99.0%) • (2) regains lost electrons at low ET(W+Jets, 95.4%)

  29. L2 electron algorithm (high pT) • Forward (1.62.6) (L2 Global 50sec) • CAL Cluster (ETEM)> 10GeV, • CAL EMF >/= 0.85 • CAL Isolation </= 0.4 • FPS 3D match of U,V ,  • (1) U, V = high • (2) U = high & V = low OR vice versa • Different detector info combined at L2 Global • FPS, CAL matching within 0.250.25 in  • Z  ee 94.3% - 97.5% (HH / HL.OR.LH) 900Hz @ 21032cm2/s 145Hz 80Hz 2 PS-Cal match

  30. B Physics: di-electron trigger • Triggering on low pT di-electrons: • Requirements: • - Low ET cut for in EM CAL (2.0 GeV) • - Low threshold PS clusters (2.0-.5.0 MIPs) • - Low pT track/charge sign (1.5 GeV/c) • L1 trigger • FPS • 2 CALEM towers > 2.5GeV • 2 PS candidates • =3 wedges • CPS • 2 CALEM towers > 2.5GeV • 2 PS candidates+Track • match within 3 strips • CAL / PS Cluster (quadrant) = factor 2 QDC rejection • Level-2 trigger: • - Matching: CAL / PS clusters in 0.250.25 in  • - EM fraction, DR(e-,e+), M (e-,e+), DF(e-,e+),ETISO

  31. B Physics: di-electron trigger • L1 & L2 Trigger Performance: • Central Region (CAL EM>2.5GeV, CPS>3MIPs) • eff (pT>1.5GeV) = 10%, Rates = 50Hz • Forward region (CAL EM>2.5GeV, FPS>5MIPs) • L1 eff (pT>1.5GeV) = 10%, Rates = 1.0-1.5KHz • L2 eff (pT>1.5GeV) = 4-5%, Rates = 50Hz

  32. Summary • L1 Trigger • electron (pT>5GeV) efficiency> 95% (7-10GeV CAL) • background rates1.5 Hz (7GeV CAL thr) • 200 - 500 Hz (10GeV CAL Thr) • di-e (pT>1.5GeV) efficiency~ 20%(cen), 10%(fwd) • background rates1-2kHz (cen+fwd) • PS/CAL Quadrant matching 2-3 in rates • L2 Trigger • electron (pT>5GeV) efficiency > 95% (10GeV ETEM) • background rates 50-100 Hz (10GeV ETEM) • di-e (pT>1.5GeV) efficiency ~ 10%(cen),5%(fwd) • background rates 100Hz(cen+fwd) • CAL EMF, Isolation, Invariant mass helps • PS/CAL 0.250.25 in  match = 2-3 in rates

  33. L1: CFT pT binning • Backup 1

  34. Central & Forward Preshower • CPS • FPS • Backup 2

  35. Trigger Task: L1 • L1 Calorimeter Dan Edmunds •  tsim_l1cal Josh K, Mary Anne C., Philippe L. • (Input = CAL cells; Output = TT’s & AND/OR) •  L1 framework & tsim_l1frm • Cristian Opazo-Castillo, Beatriz Pinero • (64 AND/OR terms from L1 CAL) •  CFT/CPS(axial) • AFE/DFE Kin Yip, Fred B. • L1 & L2 COL/BC Manuel M, Juan •  FPS • DFE Levan B., Manuel M. • L1 COL/BC Satish D., Manuel M. • L2 COL/BC Mrinmoy B. Manuel M. •  tsim_l1ft (CFT+CPS+FPS) • Kin Yip, Levan B., Mrinmoy B., Satish D. •  STT Overlap & sextant boards • Brian Connoly, Manuel M.,William Lee •  L1 Trigger Terms • Jerry Blazey • Backup 3

  36. Trigger Task: L2 •  L2 Global & tsim_l2glb (include tools) • Roger Moore, Dylan Casey • (combine CAL, PS, CFT; write EM objects) •  L2 STT & tsim_l2stt • Silvia R.,John H.,Wendy T. • (perform track fitting, track pT, impact) •  L2 CAL & tsim_l2cal • Robert Hirosky, Marc Beuhlar • (cal cluster, EMF, Isolation) •  L2 CTT & tsim_l2ctt • Dave Toback, Drew Baden • (track pT, impact, EM3, track sign) •  L2 PS & tsim_l2prs (CPS+FPS) • Mrinmoy B. • (cluster , threshold, MIP pattern, track tag) • Backup 4

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