Nikhef Scientific Meeting 2000Onne Peters D0 Muon Spectrometer December 14-15, Amsterdam Onne Peters Nikhef Jamboree 2000

Nikhef Scientific Meeting 2000Onne Peters Overview  Run 2 Upgrade status  Muon Spectrometer Hardware  Reconstruction  Outlook

Nikhef Scientific Meeting 2000Onne Peters Run 2 Tevatron Run 2a: fb -1 Run 2b: ?

Nikhef Scientific Meeting 2000Onne Peters D0 Upgrade

Nikhef Scientific Meeting 2000Onne Peters NIKHEF/Nijmegen contributions  Hardware ySilicon 10% test, testing & production yRadiation & beam loss monitors yForward Proton Detectors yHall probes  Triggers ySilicon Track Trigger yL2 Global trigger yL3 Muon trigger  Offline yMuon reconstruction yAlignment  Theory input ysingle top production

Nikhef Scientific Meeting 2000Onne Peters Upgrade status ? (no final hardware in hand) 70% Trig L3 ? Problems with L2 Alphas50%partialTrig L2  : 50% / CAL:no / CFT: 20% 100% (?)yesTrig L1 >90%100%yesMuon Forward 90%100%yesMuon Central >60%>75%yesCal. Electr. 0% (CPS waveguides; FPS not) 0%yesPreshowers 40% ( electronics, AFE, not in hand yet) 50%yesFiber tracker 40% (Interface & adapter card not in hand) >50%yesSilicon Commissioned (system test and/or cosmics) “Conservative estimate” Hooked up & checked out InstallSystem

Nikhef Scientific Meeting 2000Onne Peters Projection & goals 2001  January 15, 2001: Roll-in  March 2001: Rolled in yTake data with all detectors except preshowers y~6 weeks integrated shut-down for electronics, DAQ, triggers  May/June 2001: Detector complete yImprovements and learning  July 2001: Steady state physics data taking

Nikhef Scientific Meeting 2000Onne Peters  Full  coverage   coverage up to |  | < 2  Reasonable momentum resolution y17% for 50 GeV   L1 trigger Muon spectrometer

Nikhef Scientific Meeting 2000Onne Peters Muon Central system  PDT Drift Chambers y450 ns Drift Time (Ar-CF 4 -CH 4 ) y~1 mm resolution drift plane y~20 cm resolution axial plane yVernier pads for axial resolution

Nikhef Scientific Meeting 2000Onne Peters Muon Central system  A-  Barrel Scintillation Counters y630 counters: 4.5 degrees in , ~80 cm long yReject Out of Time background yLow Pt (1.5 GeV/c) L1 muon trigger

Nikhef Scientific Meeting 2000Onne Peters Muon Central system  Cosmic Cap Scintillation Counters yProvide timestamp for PDTs (  = 2.5 ns) yBackground rejection

Nikhef Scientific Meeting 2000Onne Peters  Scintillator pixels yL1 Trigger yTiming information y  x  = 0.1 x 2  /80 Forward system  Iarocci tracking chambers yTracking in 1 < |  | < 2 y1x1 cm 2, 60 ns drifttime

Nikhef Scientific Meeting 2000Onne Peters Muon Triggers  L1 yInput rate 2.5 MHz, output rate 5-10 kHz yTrigger on hit combinatorials  L2 yBasic track reconstruction, Pt calculation yOutput rate 1 kHz  L3 yComplete event reconstruction yOutput 50 Hz

Nikhef Scientific Meeting 2000Onne Peters Offline Reconstruction Raw data Hits Segments Muon Tracks Tracks Hit reconstruction Segment reconstruction Local track reconstruction Global track reconstruction Muon local system

Nikhef Scientific Meeting 2000Onne Peters Hit reconstruction Central system 20 ns T1T2 Ta Td Tw Tj  Signal measured on both wires: T1 & T2  Clock resolution: 1 ns  Simple algebra gives axial time and drift time  Improved axial resolution by A-  scintillators and vernier pads  Drift resolution ~ 1mm (location of chamber)  Axial resolution ~ 1 cm (resolution of scintillator)

Nikhef Scientific Meeting 2000Onne Peters Hit reconstruction Forward system T1 Td Ta  Only one time measured  Clock resolution: 18.8 ns  Pixel scintillator used for axial coordinate  Drift resolution: 1 mm  Axial resolution: 1 cm

Nikhef Scientific Meeting 2000Onne Peters Hit reconstruction efficiency

Nikhef Scientific Meeting 2000Onne Peters Segment reconstruction  Segment: Linear track segment (A, B, C, BC)  Reconstruction based on a link & tree algorithm

Nikhef Scientific Meeting 2000Onne Peters Segment reconstruction

Nikhef Scientific Meeting 2000Onne Peters Segment reconstruction  Forward system  Central system

Nikhef Scientific Meeting 2000Onne Peters Track Reconstruction  Matches straight segments in middle of toroid  Non-uniform B-field propagation through toroid  Angle ~ 1/P T  Global match with inner tracker C Layer B Layer A Layer Toroid

Nikhef Scientific Meeting 2000Onne Peters Track reconstruction  p/p sim Central system  p/p sim Forward system

Nikhef Scientific Meeting 2000Onne Peters Track Reconstruction Reconstructed Z mass muon system only

Nikhef Scientific Meeting 2000Onne Peters Cosmic ray test  Cosmic ray test of central system y6 PDT Chambers yAll A-  scintillation counters yAll Cosmic Cap scintillation counters  Very good test of hard- and software  12/15: Cosmic ray test yMuon + calorimeter

Nikhef Scientific Meeting 2000Onne Peters Cosmic ray test

Nikhef Scientific Meeting 2000Onne Peters Outlook  Run 2 starts March 1 st  Hardware ready but only 50% channels hooked up  Triggers in reasonable shape  Reconstruction software developing fast  Exciting times ahead!

Nikhef Scientific Meeting 2000Onne Peters Physics analyses  B-physics yB jet inclusive cross section yB s  K s + J/   Tau physics  Top physics  Higgs physics

Nikhef Scientific Meeting 2000Onne Peters Outlook LEP2 searches EW fits Combined integrated luminosity ?: 30 fb -1