12 August 2004 Butler, 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 LandsbergMeenakshi Narain

Search for T, T ! +-

John ButlerRyan Hooper

12 August 2004 Butler, 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 MV=MA=MT, which controls the rate of !T

Z WTWT,WWWZ

f f, g g f f, g gff,gg

bb,

bc dominate)

12 August 2004 Butler, Hooper, Landsberg, Narain

PRL – analysis by Heintz and Narain

Vary mass parameter MV=MA=MT

RunI Results

Difference in T and T mass

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

Dielectron Analysis

12 August 2004 Butler, Hooper, Landsberg, Narain

Dielectron Analysis

Blue curves: m(T)-m(T)=60 GeVMagenta curves:m(T)-m(T)=100 GeV

For a given setUppsermost curve MT=500 GeVMiddle curve MT=200 GeVLowermost curve MT = 100 GeV

12 August 2004 Butler, Hooper, Landsberg, Narain

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

12 August 2004 Butler, 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 pT > 15 GeV

Cut on (1 + 2) to remove cosmics

|det| < 2

TC mass dependent cut window

12 August 2004 Butler, 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 • pT re-weighting procedure

1% overall error assumed Results

For MT = 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 2004 Butler, 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.