15 th March 2004 Search for Neutral Search for Neutral Supersymmetric Higgs Bosons Supersymmetric Higgs Bosons at D at D Ø Ø Tim Scanlon Imperial College Overview•DØ Detector and the Tevatron •Super-symmetric Higgs Bosons Searches •Triggers and b-tagging •Analysis and b-tagging •Results •Conclusions
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Search for Neutral Supersymmetric Higgs Bosons at D Ø
Search for Neutral Supersymmetric Higgs Bosons at D Ø. Tim Scanlon Imperial College. Overview. DØ Detector and the Tevatron Super-symmetric Higgs Bosons Searches Triggers and b-tagging Analysis and b-tagging Results Conclusions. D Ø and Tevatron Performance. Tevatron - PowerPoint PPT Presentation
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15th March 2004
Search for Neutral Search for Neutral Supersymmetric Higgs Bosons at Supersymmetric Higgs Bosons at
DDØØ
Tim Scanlon
Imperial College
Overview •DØ Detector and the Tevatron•Super-symmetric Higgs Bosons Searches
•Triggers and b-tagging•Analysis and b-tagging
•Results•Conclusions
15th March 2004
DDØ and Tevatron PerformanceØ and Tevatron Performance
Tevatron
• Regularly Lint ~ 1x1032 cm-2s-1
• Expect Lint ~ 1.5x1032 cm-2s-1 in coming year
DØ• DØ Detector running well,
data taking efficiency ~ 90 %• ~ 0.6 fb-1 of data recorded on
tape
TeVs 96.1pp> 1x1032
15th March 2004
DDØ DetectorØ DetectorRun II Upgrades Includes• New Tracking System
Silicon Microstrip Tracker (SMT) Central Fibre Tracker 2T Solenoid
• Upgraded Trigger System New Data Acquisition System (DAQ) L2 Silicon Track Trigger (STT)
DØ Trigger• Three levels of trigger
Level 1 Hardware based Level 2 Hardware/Software Level 3 Software based
• Each level has increasingly sophisticated event reconstruction
• Cut rate from 1.7 MHz to 50Hz
15th March 2004
Supersymmetric Higgs BosonsSupersymmetric Higgs Bosons• Minimal Supersymmetric extension of the
standard model (MSSM) + Higgs• Five physical Higgs bosons
h, H, A and H±
tan() = ratio of vacuum expectation values of Higgs fields
H, h and A• Coupling to b-quark enhanced by tan()
Production enhanced by tan ²()• Degenerate in mass and
indistinguishable Doubles the cross section
• Mainly Decay to bb Signal 3 or 4 b-jets Large multi-jet background
+
+
hb
hbb
tan() = 30
A
hH
Total
Critical components of search b-jet identification (b-tagging) Trigger
15th March 2004
• A b may travel several mm before decaying into a jet