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/ Search for  T,  T ! e + e - Greg Landsberg Meenakshi Narain Search for  T,  T !  +  - John Butler Ryan Hooper

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)

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

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

12 August 2004Butler, Hooper, Landsberg, Narain Dielectron Analysis

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

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

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

12 August 2004Butler, Hooper, Landsberg, Narain Search for Technicolor to Dimuons  Acceptance  Efficiency  Pythia 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

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.