Search for  T ,  T ! e + e - ,  +  -

1. 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 Butler, Hooper, Landsberg, Narain

2. 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 pT0 pT+/- • Decays • Cross section for depends on two main model parameter choices: • Difference in the T and T mass • The mass parameter MV=MA=MT, which controls the rate of !T • wT gpTr0TpT pT r+_T  pT pT •  gZ WpT, ZpT  WpT,ZpT •  3pT WW  WZ •  f f, g g  f f, g g pT ff,gg(pT0 bb, pT+/- bc dominate) Butler, Hooper, Landsberg, Narain

3. RunI Results • PRL – analysis by Heintz and Narain • Difference in T and T mass • Vary mass parameter MV=MA=MT Butler, Hooper, Landsberg, Narain

4. Search for Technicolor to Dielectrons • Search for rT/wT 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 Butler, Hooper, Landsberg, Narain

5. Dielectron Analysis Butler, Hooper, Landsberg, Narain

6. Dielectron Analysis Blue curves: m(T)-m(T)=60 GeV Magenta curves: m(T)-m(T)=100 GeV For a given set Uppsermost curve MT=500 GeV Middle curve MT=200 GeV Lowermost curve MT = 100 GeV Butler, Hooper, Landsberg, Narain

7. Limits from dielectron Channel • 95% C.L. • m(T ,T)-m(T)=60 GeV • m(T) > 367 GeV for MT = 500 GeV • m(T) > 340 GeV for MT = 100 GeV • m(T ,T)-m(T)=100 GeV • m(T ,T) > 355 GeV for MT = 500 GeV • m(T ,T) > 240 GeV for MT = 100 GeV • Compare to RunI • m(T ,T)-m(T)=60 GeV • m(T ,T) > 250 GeV for MT = 100 GeV • m(T)-m(T)=100 GeV • m(T ,T) > 230 GeV for MT = 400 GeV • m(T ,T) > 206 GeV for MT = 100 GeV Butler, Hooper, Landsberg, Narain

8. Search for Technicolor to Dimuons • Search for rT/wT m+m- as a bump/excess at high mm 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 • pT > 15 GeV • Cut on (h1 + h2) to remove cosmics • |hdet| < 2 • TC mass dependent cut window Butler, Hooper, Landsberg, Narain

9. Search for Technicolor to Dimuons • Acceptance ´ Efficiency • Pythia 6.220 implementation of TCSM • Generated 100k events for each mass point • pm smeared using pmcs prescription (DØ note 4297) • Use Ryan’s • Map in h-f for Acc´e • pT re-weighting procedure • 1% overall error assumed • Results • For MT = 100 GeV and (rT -pT) = 60 GeV, exclude masses < 240 GeV • Exceeds the Run I ee limit • First in dimuons for DØ • Combine with the ee limit Butler, Hooper, Landsberg, Narain

10. 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. Butler, Hooper, Landsberg, Narain