DØ Experiment l Physicists Susan Blessing Sharon Hagopian Vasken Hagopian Stephan L. Linn Harrison B. Prosper Horst D. Wahl Bill Lee Silvia Tentindo-Repond l Graduate Students Brian Connolly Russell Gilmartin Attila Gonenc Craig Group Jose Lazoflores Yuri Lebedev Sinjini Sengupta l Undergraduate student: Burnham Stokes l Research Interests Top quarks Supersymmetry Leptoquarks Higgs l Recent Work Measurement of top quark mass Search for leptoquarks Search for supersymmetric top quarks

CMS Experiment l Physicists S. Hagopian V. Hagopian K. Johnson H.B. Prosper H.D. Wahl l Engineers: Maurizio Bertoldi James Thomaston l Undergraduate student: Lucas Naveira l Research Interests Supersymmetry Higgs l Recent Work R&D of a laser-based monitoring system for the CMS calorimeter R&D of devices to scan large scintillating tiles. Coordination of test beam experiments at CERN

Summary l Dzero: 2000 to 2005 Will remain the main focus of our research program for the next seven years. We have a wonderful window of opportunity to make major contributions to our field. l CMS: 2005 and beyond The LHC will vastly increase our ability to probe Nature. We are very confident that CMS will have a profound impact on our understanding of particle physics. l Hellaz: 2003 (?) and beyond

Research Program of FSU – HEP group l DØ Experiment To study 2 TeV proton antiproton collisions Fermilab, Batavia, Illinois Next run begins in April 2001 l CMS Experiment To study 14 TeV proton antiproton collisions CERN, Geneva, Switzerland First run begins in 2005 l Hellaz Experiment To study 1 MeV neutrinos from the Sun. When?!!!

Collisions at the Tevatron pp Collisions  qq(g) Interactions Underlying Event u u d g q q u u d Hard Scatter Fermilab

Questions at the Tevatron l The Standard Model Electro-Weak (EM + Weak Interact’s)  W,Z,  + quarks & leptons  Most Accurate Theory ever ! (but only for fundamental particles)  Simple Processes  Real Tests QCD (Strong Force)  gluons & quarks  High E  Accurate Predictions Low E  Not a simple Theory  Range of E’s accessible for partons in proton Properties of Particles  All Quarks and Leptons Produced (only place for top quark)  All Gauge Bosons………..almost  What about the Higgs?

More Questions l The SM works great ! Why change it ? Has 18 arbitrary parameters  Where do they come from ? Is the Higgs really what we think it should be ? l 2 Strategies: Look HarderPrecision Get a Bigger HammerEnergy l The Tevatron is well suited to both of these strategies

Fermilab Upgrade

D  Upgrade

D  Upgrade Tracking Silicon Tracker Four layer barrels (double/single sided) Interspersed double sided disks 793,000 channels Fiber Tracker Eight layers sci-fi ribbon doublets (z-u-v, or z) 74,  m fibers w/ VLPC readout Preshowers Central Scintillator strips – 6,000 channels Forward – Scintillator strips – 16,000 channels Solenoid – 2T superconducting cryostat

Silicon Tracker 7 barrels 50 cm 12 Disks “F” 8 Disks“H” 3 1/7 of the detector (large-z disks not shown) 387k ch in 4-layer double sided Si barrel (stereo) 405k ch in interspersed disks (double sided stereo) and large-z disks 1/2 of detector

Silicon Tracker -Detectors Disks “F” disks wedge (small diameter):  144 double sided detectors, 12 wedges = 1disk  50  m pitch, +/-15 stereo  7.5cm long, from r=2.5 to 10cm, at z=6,19,32,45,50,55 cm “H” disk (large diameter):  384 single sided detectors  50  m pitch  from r= cm, z= 94, 126 cm Barrels 7 modular, 4 layer barrel segments single sided:  layers 1, 3 in two outermost barrels. double sided:  layers 1, 3 have 90 o stereo (mpx’d 3:1) 50 & 100  m pitch, 2.1 cm wide  layers 2,4 have small angle stereo (2 o ) 50 & 62.5  m pitch, 3.4 cm wide 12cm two detectors wire bonded

Trigger Configuration L2: Combined objects (e, , j) L1: towers, tracks L1CAL L2STT Global L2 L2CFT L2PS L2Cal L1PS L1CFT L2 Muon L1 Muon L1FPD Detector L1 TriggerL2 Trigger 7 MHz 10 kHz 1 kHz CAL FPS CPS CFT SMT Muon FPD

Feynman Diagrams q q q’ q’q’  g q q q’q’ Z0Z0 q q q’,l, WW q q’ q1,lq1,l q 2,

Questions at the Tevatron l The Standard Model Electro-Weak (EM + Weak Interactions)  W,Z,  + quarks & leptons  Most Accurate Theory ever ! (but only for fundamental particles)  Simple Processes  Real Tests QCD (Strong Force)  gluons & quarks  High E  Accurate Predictions Low E  Not a simple Theory  Range of E’s accessible for partons in proton Properties of Particles  All Quarks and Leptons Produced (only place for top quark)  All Gauge Bosons………..almost  What about the Higgs?

More Questions l The SM works great ! Why change it ? Has 18 arbitrary parameters  Where do they come from ? Is the Higgs really what we think it should be ? l 2 Strategies: Look HarderPrecision Get a Bigger HammerEnergy l The Tevatron is well suited to both of these strategies

Illustrious History of D  D  Roll-In: February 1992 Run I: 92  +  + 96  125 pb  at 1.8 TeV >450 Physicists (  70 Grad Students)  50 Instititutions (10 countries) l Approx 100 Publications…..so far EW Physics Top Physics New Phenomena B Physics QCD l Top co-Discovered: March 95 M t =  5.2  4.9 GeV/c 2  t = 5.6  1.8 pb N cand = 57 N bgd = 20.6  2.4

(not so) Illustrious Hist. l Higgs: only Limits LEP  M H > 89.3 GeV/c 2 l No Physics Beyond SM found yet l But there is Hope……..

Our Friend: the b-Quark l Tag Top Decays t  bW ~ 100% Tag Higgs (H  bb)  (H  ff)  m f 2 New Particles  b’s New Physics couples to mass l CP Violation Matter / Antimatter Asymmetry Should be Large in B systems l QCD perturb  non-perturb boundary

Our Enemy: Rates l Too Much Physics Collision Rate10 MHz Data to Tape 20 Hz l Trigger ID interesting events as quickly as possible  132 ns between collisions ! 3 Level System in D 

Silicon Track Trigger l Goals: Sharpen P T Measurement Identify b  events l B Event Properties Impact Param / Vertex Triggers Collision B-Hadron: Flight Length ~ mm’s Decay Vertex B Decay Products Impact Parameter

Using Silicon Information l Include Si hits on CFT Track in L2 trigger l STT Preprocessor SMT Detector Cluster Finder CFT Tracks (L1 Trig) Associate Clusters to Tracks Re-Fit Track w/ Si Clusters Global L2 Trigger 50  s Time Budget