Strong EWSB in Top Quark Production at ILC

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Strong EWSB in Top Quark Production at ILC
Praha, Mar 30, 2006

• Ivan Melo

M. Gintner, I. Melo, B. Trpiová
(University of ilina)
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Outline

• Motivation for new vector (?) resonances
  Strong EW Symmetry Breaking (SEWSB)
• Vector resonance model
• ? signal at future ee- colliders
• ee- ? ?? tt
• ee- ? t t
• Beamstrahlung

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EWSB SU(2)L x U(1)Y ? U(1)Q

• Weakly interacting models
• - SUSY
• - Little Higgs
• Strongly interacting models
• - Technicolor

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Summary of the DCR Physics Group

• Strongly interacting Higgs sector a priority
  !!!!
• - Summarize/update the scenario with
  resonances
• - See for new studies with the chiral approach

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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 ? WL WL WL WL ? t t t t ? t t
t
t
t
p WL
L i gp M? /v (p- ?µ p - p ?µ p-) ?0µ
gt t ?µ t ?0µ gt t ?µ ?5 t ?0µ
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• International Linear Collider ee- at 1 TeV

ee ? ?tt ? WW tt ee ? ?tt ? tt tt
ee ? WW ee ? tt
ee ? ?? WW
ee ? ?? tt
Large Hadron Collider pp at 14 TeV
pp ? ?tt ? WW tt pp ? ?tt ? tt tt
pp ? WW pp ? tt
pp ? jj WW
pp ? jj tt
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Chiral effective Lagrangian SU(2)L x
SU(2)R global, SU(2)L x U(1)Y local

L Lkin Lnon.lin. s model - a v2 /4 Tr(?µ
i gv ?µ . t/2 )2 Lmass
LSM(W,Z) b1 ?L i ?µ (u?µ u i
gv ?µ . t/2 u i g/6 Yµ) u ?L
b2 ?R Pb i ?µ (u ?µ u i gv ?µ . t/2 u i g/6
Yµ) u Pb ?R ?1 ?L i ?µ u Aµ ?5 u
?L ?2 ?R P? i ?µ u Aµ ?5 u P?
?R
BESS
Our model
Standard Model with Higgs replaced
with ?
?µ u(?µ i g/2 Yµt3)u u(?µ i g Wµ .
t/2)u/2 Aµ u(?µ i g/2 Yµt3)u - u(?µ i g
Wµ . t/2)u/2 u exp(i p . t /2v) ?L
(tL,bL) Pb diag(p1,p2)
gp M? /(2 v gv) gt gv b2 /4
M? va v gv /2
t
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Unitarity constraints
Low energy constraints
gv 10 ? gp 0.2 M?
(TeV) b2 ?2 0.04 ? gt gv b2 /
4 b1 ?1 0.01 ? b1 0

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

gp 1.75 (M? 700 GeV) gt 1.7 (M?
700 GeV)
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Partial (G?WW) andtotal width Gtot of ?
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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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N(?) N(no res.)
v(N(no res.))
R
S/vB gt 5
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e- e ? t t
?
different from Higgs !
xy560 nm z0.40 mm n2x1010
? (M 700 GeV, b20.08, g20)
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Beamstrahlung

• Bunch parameters at IP
• TESLA (500 GeV)
• N 2 x 1010
• sx 554 nm
• sy 5 nm
• sz 0.3 mm
• dBS 0.02 0.2
• L N2 Hd f/ 4psxsy

SLC (SLAC) N 5 x 1010 sx 1500 nm sy 1500
nm sz 1.05 mm dBS 0.00045
pinch effect
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E(b) Ne/(2pe0 L R2) b R 2 sx 2 sy
L is bunch length
b
e-
e bunch
y(z) b0 cos(v3Dy/2)1/2 z/L Dy 2N
resz/?sy(sxsy)
y
z
x
Disruption
Pinch effect
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p
e-
r
F eE(b)
z
r p/eE(b)
PW 2ke2?4/(3r2), v?c1 ?E PW?t PW?z dBS
? ?E /E 4N2? re3/3v3 sz (sxsy)2
2 20
s
L N2 Hd f/ 4psxsy Dy 2N resz/?sy(sxsy)
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Conclusions

• strong ?-resonance model (modified BESS)
• ee- ? ??tt R 26 at CM energy 1 TeV, L
  200 fb-1
• ee- ? tt Lscan 1 fb-1