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12 August 2004Butler, Hooper, Landsberg, Narain Search for T, T ! e + e -, + - Particles predicted by the Low Scale Technicolor Model TCSM - Eichten, Lane and Womersley TCSM2 - K. Lane hep-ph/9903372 Search for T, T ! e + e - Greg Landsberg Meenakshi Narain Search for T, T ! + - John Butler Ryan Hooper
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12 August 2004Butler, Hooper, Landsberg, Narain Low Scale Technicolor Phenomenology Technicolor Models requiring large number of technifermion doublets: Topcolor-assisted Technicolor Walking Technicolor Low Scale Technicolor Phenomenology: color singlet vectors (200 – 400 GeV ) produced in pp collisions Decays: color-singlet scalars lightest technihadrons Decays Cross section for depends on two main model parameter choices: Difference in the T and T mass The mass parameter M V =M A =M T, which controls the rate of ! T Z W T W T, WW WZ f f, g g f f, g g ff,gg bb, bc dominate)
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12 August 2004Butler, Hooper, Landsberg, Narain PRL – analysis by Heintz and Narain Vary mass parameter M V =M A =M T RunI Results Difference in T and T mass
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12 August 2004Butler, Hooper, Landsberg, Narain Search for Technicolor to Dielectrons Search for T / T e + e - as a bump/excess at high dielectron mass Analysis based on Landsberg, Perez LED and Z’ searches Use identical cuts same # data events and same background estimates Intrinsic widths of T, T are about 0.5 GeV Thus resonance width dominated by detector resolution Optimized mass dependent cut window for this particular search
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12 August 2004Butler, Hooper, Landsberg, Narain Dielectron Analysis
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12 August 2004Butler, Hooper, Landsberg, Narain Dielectron Analysis Blue curves: m( T )-m( T )=60 GeV Magenta curves: m( T )-m( T )=100 GeV For a given set Uppsermost curve M T =500 GeV Middle curve M T =200 GeV Lowermost curve M T = 100 GeV
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12 August 2004Butler, Hooper, Landsberg, Narain Limits from dielectron Channel 95% C.L. m( T, T )-m( T )=60 GeV m( T ) > 367 GeV for M T = 500 GeV m( T ) > 340 GeV for M T = 100 GeV m( T, T )-m( T )=100 GeV m( T, T ) > 355 GeV for M T = 500 GeV m( T, T ) > 240 GeV for M T = 100 GeV Compare to RunI m( T, T )-m( T )=60 GeV m( T, T ) > 250 GeV for M T = 100 GeV m( T )-m( T )=100 GeV m( T, T ) > 230 GeV for M T = 400 GeV m( T, T ) > 206 GeV for M T = 100 GeV
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12 August 2004Butler, Hooper, Landsberg, Narain Search for Technicolor to Dimuons Search for T / T as a bump/excess at high mass Motivation identical to the dielectron search Analysis based on Ryan Hooper’s LED and Z’ searches (DØ notes 4229 & 4230) updated for a 250 pb -1 data set Use identical cuts same # data events and same background estimates p T > 15 GeV Cut on ( 1 + 2 ) to remove cosmics | det | < 2 TC mass dependent cut window
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12 August 2004Butler, Hooper, Landsberg, Narain Search for Technicolor to Dimuons Acceptance Efficiency Pythia 6.220 implementation of TCSM Generated 100k events for each mass point p smeared using pmcs prescription (DØ note 4297) Use Ryan’s Map in for Acc p T re-weighting procedure 1% overall error assumed Results For M T = 100 GeV and ( T T ) = 60 GeV, exclude masses < 240 GeV Exceeds the Run I ee limit First in dimuons for DØ Combine with the ee limit
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12 August 2004Butler, Hooper, Landsberg, Narain Conclusion We have performed a search for T, T ! e + e -, + - We have extended the limit significantly in the dielectron final state. The best results so far. Sent to group/EB for review We have a new analysis in the dimuon final state We combined the limit for the two final states Will be writing this up shortly and sending to the group/EB for review.
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