Phenomenology of Vector Resonances from SEWSB at Future e e Colliders

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Phenomenology of Vector Resonances from SEWSB at
Future ee- Colliders
14th KSF, Smolenice Oct 13, 2004

• Ivan Melo

D. Bruncko (IEP SAS Kosice) M. Gintner
(University of Zilina) I. Melo (University of
Zilina)
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Outline

• Motivation for new vector (?)
• resonances
• Vector resonance models
• ? signals in ee- ? ??tt

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Chiral SB in QCD

• SU(2)L x SU(2)R ? SU(2)V , vev
  90 MeV

EWSB
SU(2)L x SU(2)R ? SU(2)V , vev 246
GeV
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WL WL ? t t
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A simple Lagrangian

• L i gp M?/v (p- ?µ p - p ?µ p- )?0µ
• gV t ?µ t ?0µ gA t ?µ ?5 t
  ?0µ (1)

Chiral effective Lagrangian
L - v2 Tr Aµ Aµ - a v2 /4 Tr(?µ i g''
?µ . t/2 )2 b1 IbL b2 IbR ...
(2)
gp M? /(2 v g''), gV g'' b2
/4(1b2), M? va v g''/2.
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Unitarity constraints

• WL WL ? WL WL , WL WL ? t t, t t ? t t

gp 1.75 (M? 700 GeV) gV 1.7 (M?
700 GeV)
Low energy constraints
g 10 b2 0.08
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Subset of fusion diagrams approximations
(Pythia)
Full calculation of 66 diagrams at tree level
(CompHEP)
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Pythia vs CompHEP

• ? (M 700 GeV, G 12.5 GeV, g
  20, b2 0.08)
• Before cuts
• vs (GeV) 800
  1000 1500
• Pythia (fb) 0.35
  0.95 3.27
• CompHEP (fb) 0.66
  1.16 3.33

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Backgrounds (Pythia)

• ee- ? tt ?
• ee- ? ee- tt
• s(0.8 TeV) 300.3 1.3 fb ? 0.13 fb
  (0.20 fb)
• s(1.0 TeV) 204.9 2.4 fb ? 0.035 fb
  (0.16 fb)

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Conclusions

• ? in ee- ? ??tt sensitive probe of mt
  physics
• s(1 TeV) 0.16 (0.035) fb
• R values up to 8