Pseudo Axions in Little-Higgs Models - DESYreuter/downloads/lcws05.pdf · Pseudo Axions in...
Transcript of Pseudo Axions in Little-Higgs Models - DESYreuter/downloads/lcws05.pdf · Pseudo Axions in...
/.α?〈〈〈↑↓〉〉〉ω
Pseudo Axions in Little-Higgs Models
Jurgen Reuter— DESY Theory Group —〈[email protected]〉
in collaboration with: W. Kilian (DESY), D. Rainwater (Rochester)
LCWS Stanford, March 21, 2005
J. Reuter Pseudo Axions in LHM LCWS 2005, i
/.α?〈〈〈↑↓〉〉〉ω Contents
1 Little Higgs Models . . . . . . . . . . . . . . . . . 1◦ Hierarchy Problem ◦ Higgs as Pseudo-Goldstone Boson ◦ Scales and
Masses ◦ Generic properties
2 Pseudo Axions in LHM . . . . . . . . . . . . . . . 5◦ Symmetry breaking and anomalous U(1) ◦ Properties of Pseudo Axions
◦ The µ Model (Simple-Group Model) ◦ Parameters and all that... ◦ η
Branching Ratios ◦ Production at LHC ◦ Pseudo Axions at the Linear
Collider ◦ Pseudo Axions at the Photon Collider
3 Conclusions . . . . . . . . . . . . . . . . . . . . . 15
J. Reuter Pseudo Axions in LHM LCWS 2005, ii
/.α?〈〈〈↑↓〉〉〉ω Hierarchy Problem
250
500
750
103 106 109 1012 1015 1018
Mh[GeV]
Λ[GeV]
Motivation: Hierarchy Problem
• Effective theories below a scaleΛ ⇒
J. Reuter Pseudo Axions in LHM LCWS 2005, 1
/.α?〈〈〈↑↓〉〉〉ω Hierarchy Problem
250
500
750
103 106 109 1012 1015 1018
Mh[GeV]
Λ[GeV]
Motivation: Hierarchy Problem
• Effective theories below a scaleΛ ⇒
• Loop integration cut off at order∼ Λ:
∼ Λ2
J. Reuter Pseudo Axions in LHM LCWS 2005, 1
/.α?〈〈〈↑↓〉〉〉ω Hierarchy Problem
250
500
750
103 106 109 1012 1015 1018
Mh[GeV]
Λ[GeV]
Motivation: Hierarchy Problem
• Effective theories below a scaleΛ ⇒
• Loop integration cut off at order∼ Λ:
∼ Λ2
� Problem: Naturally, mh ∼ O(Λ2):
m2h = m2
0 + Λ2 × (loop factors)
♦ Light Higgs favored by EW preci-sion observables (mh < 0.5 TeV)
• mh � Λ ⇔ Fine-Tuning !?
• Solution: Mechanism for elimi-nation of loop contributions
J. Reuter Pseudo Axions in LHM LCWS 2005, 1
/.α?〈〈〈↑↓〉〉〉ω Higgs as Pseudo-Goldstone Boson
Invent (approximate) symmetry to protect particle masses
J. Reuter Pseudo Axions in LHM LCWS 2005, 2
/.α?〈〈〈↑↓〉〉〉ω Higgs as Pseudo-Goldstone Boson
Invent (approximate) symmetry to protect particle masses
Traditional (SUSY):Spin-Statistics =⇒ Loops ofbosons and fermions
J. Reuter Pseudo Axions in LHM LCWS 2005, 2
/.α?〈〈〈↑↓〉〉〉ω Higgs as Pseudo-Goldstone Boson
Invent (approximate) symmetry to protect particle masses
Traditional (SUSY):Spin-Statistics =⇒ Loops ofbosons and fermions
Little Higgs:Gauge group structure =⇒ Loops ofparticles of like statistics
Old Idea: Georgi/Pais, 1974; Georgi/Dimopoulos/Kaplan, 1984
Light Higgs as Pseudo-Nambu-Goldstone Boson (PNGB) ⇔ spontaneouslybroken (approximate) global symmetry; non-linear sigma model
� w/o Fine-Tuning: v ∼ Λ/4π
J. Reuter Pseudo Axions in LHM LCWS 2005, 2
/.α?〈〈〈↑↓〉〉〉ω Higgs as Pseudo-Goldstone Boson
Invent (approximate) symmetry to protect particle masses
Traditional (SUSY):Spin-Statistics =⇒ Loops ofbosons and fermions
Little Higgs:Gauge group structure =⇒ Loops ofparticles of like statistics
Old Idea: Georgi/Pais, 1974; Georgi/Dimopoulos/Kaplan, 1984
Light Higgs as Pseudo-Nambu-Goldstone Boson (PNGB) ⇔ spontaneouslybroken (approximate) global symmetry; non-linear sigma model
� w/o Fine-Tuning: v ∼ Λ/4π
New Ingredience: Arkani-Hamed/Cohen/Georgi/. . . , 2001
Gauge group structure eliminates quadratic diver-gences 1-loop level =⇒ 3-scale model
J. Reuter Pseudo Axions in LHM LCWS 2005, 2
/.α?〈〈〈↑↓〉〉〉ω Scales and Masses
µ
Λ
F
v
O(10 TeV)
O(1 TeV)
O(250 GeV)
� Scale Λ: global SB, new dyman-ics, UV embedding
� Scale F: Pseudo-Goldstonebosons, new vector bosons andfermions
� Scale v: Higgs, W±, Z, `±, . . .
J. Reuter Pseudo Axions in LHM LCWS 2005, 3
/.α?〈〈〈↑↓〉〉〉ω Scales and Masses
µ
Λ
F
v
O(10 TeV)
O(1 TeV)
O(250 GeV)
� Scale Λ: global SB, new dyman-ics, UV embedding
� Scale F: Pseudo-Goldstonebosons, new vector bosons andfermions
� Scale v: Higgs, W±, Z, `±, . . .
Boson masses radiative(Coleman-Weinberg), but:Higgs protected by symmetriesagainst quadratic corrections1-loop level
J. Reuter Pseudo Axions in LHM LCWS 2005, 3
/.α?〈〈〈↑↓〉〉〉ω Scales and Masses
µ
Λ
F
v
O(10 TeV)
O(1 TeV)
O(250 GeV)
� Scale Λ: global SB, new dyman-ics, UV embedding
� Scale F: Pseudo-Goldstonebosons, new vector bosons andfermions
� Scale v: Higgs, W±, Z, `±, . . .
Boson masses radiative(Coleman-Weinberg), but:Higgs protected by symmetriesagainst quadratic corrections1-loop level
� How does Little Higgs actuallywork?
J. Reuter Pseudo Axions in LHM LCWS 2005, 3
/.α?〈〈〈↑↓〉〉〉ω Scales and Masses
µ
Λ
F
v
O(10 TeV)
O(1 TeV)
O(250 GeV)
� Scale Λ: global SB, new dyman-ics, UV embedding
� Scale F: Pseudo-Goldstonebosons, new vector bosons andfermions
� Scale v: Higgs, W±, Z, `±, . . .
Boson masses radiative(Coleman-Weinberg), but:Higgs protected by symmetriesagainst quadratic corrections1-loop level
� How does Little Higgs actuallywork?
H→ H0
G1 → G ′1 G2 → G ′
1[H1, H2] 6= 0
/H1 ⊂ H /H2 ⊂ H
g1 6= 0 g2 6= 0
MH ∼ g1g2 Λ/16π2
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/.α?〈〈〈↑↓〉〉〉ω Generic properties
Kilian/JR (2004), . . . , PDG (2004), Schmaltz (2005)
• Extended scalar (Higgs-) sector Extended global symmetry
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/.α?〈〈〈↑↓〉〉〉ω Generic properties
Kilian/JR (2004), . . . , PDG (2004), Schmaltz (2005)
• Extended scalar (Higgs-) sector Extended global symmetry
• Specific form of the potential:
V(h, Φ) = C1F2∣∣∣∣Φ +
iFh⊗ h
∣∣∣∣2
+ C2F2∣∣∣∣Φ −
iFh⊗ h
∣∣∣∣2
mh=0 @ 1-loop-level, 〈h〉 , mh ∼ v, MΦ ∼ F, i · 〈Φ〉 ∼ v2/F , h/Φ mix
J. Reuter Pseudo Axions in LHM LCWS 2005, 4
/.α?〈〈〈↑↓〉〉〉ω Generic properties
Kilian/JR (2004), . . . , PDG (2004), Schmaltz (2005)
• Extended scalar (Higgs-) sector Extended global symmetry
• Specific form of the potential:
V(h, Φ) = C1F2∣∣∣∣Φ +
iFh⊗ h
∣∣∣∣2
+ C2F2∣∣∣∣Φ −
iFh⊗ h
∣∣∣∣2
mh=0 @ 1-loop-level, 〈h〉 , mh ∼ v, MΦ ∼ F, i · 〈Φ〉 ∼ v2/F , h/Φ mix
• Extended gauge sector: SM ′ × G→ SM =⇒ Additional EW gauge bosons:
B ′, Z ′, W′± (Hypercharge singlets & triplets)
J. Reuter Pseudo Axions in LHM LCWS 2005, 4
/.α?〈〈〈↑↓〉〉〉ω Generic properties
Kilian/JR (2004), . . . , PDG (2004), Schmaltz (2005)
• Extended scalar (Higgs-) sector Extended global symmetry
• Specific form of the potential:
V(h, Φ) = C1F2∣∣∣∣Φ +
iFh⊗ h
∣∣∣∣2
+ C2F2∣∣∣∣Φ −
iFh⊗ h
∣∣∣∣2
mh=0 @ 1-loop-level, 〈h〉 , mh ∼ v, MΦ ∼ F, i · 〈Φ〉 ∼ v2/F , h/Φ mix
• Extended gauge sector: SM ′ × G→ SM =⇒ Additional EW gauge bosons:
B ′, Z ′, W′± (Hypercharge singlets & triplets)
• Extended Top sector: new quarks, t, t ′ loops ⇒ M2h < 0 ⇒ EWSB
J. Reuter Pseudo Axions in LHM LCWS 2005, 4
/.α?〈〈〈↑↓〉〉〉ω Symmetry breaking and anomalous U(1)
• Higgs ∈ PNGB⇒ rank reduction of the global symmetry group
• Higgs corresponds to nondiagonal generator (QCD: kaon)
J. Reuter Pseudo Axions in LHM LCWS 2005, 5
/.α?〈〈〈↑↓〉〉〉ω Symmetry breaking and anomalous U(1)
• Higgs ∈ PNGB⇒ rank reduction of the global symmetry group
• Higgs corresponds to nondiagonal generator (QCD: kaon)
• diagonal generator: η in QCD; couples to fermions as a pseudoscalar,behaves as a axion⇒ Pseudo Axion of LHM
• analogous particles: techni-axion, topcolor-axion, (N)MSSM-axion
J. Reuter Pseudo Axions in LHM LCWS 2005, 5
/.α?〈〈〈↑↓〉〉〉ω Symmetry breaking and anomalous U(1)
• Higgs ∈ PNGB⇒ rank reduction of the global symmetry group
• Higgs corresponds to nondiagonal generator (QCD: kaon)
• diagonal generator: η in QCD; couples to fermions as a pseudoscalar,behaves as a axion⇒ Pseudo Axion of LHM
• analogous particles: techni-axion, topcolor-axion, (N)MSSM-axion
• influences EW and T phenomenology
J. Reuter Pseudo Axions in LHM LCWS 2005, 5
/.α?〈〈〈↑↓〉〉〉ω Symmetry breaking and anomalous U(1)
• Higgs ∈ PNGB⇒ rank reduction of the global symmetry group
• Higgs corresponds to nondiagonal generator (QCD: kaon)
• diagonal generator: η in QCD; couples to fermions as a pseudoscalar,behaves as a axion⇒ Pseudo Axion of LHM
• analogous particles: techni-axion, topcolor-axion, (N)MSSM-axion
• influences EW and T phenomenology
QCD-(PQ) axion: LAx. = 1Λ
αs
8π2 AgηGµνGµν, Fµν = 12εµνρσFρσ
Anomalous U(1)η:
J. Reuter Pseudo Axions in LHM LCWS 2005, 5
/.α?〈〈〈↑↓〉〉〉ω Properties of Pseudo Axions
• η EW singlet
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/.α?〈〈〈↑↓〉〉〉ω Properties of Pseudo Axions
• η EW singlet
• ξ = exp[
iFη
]exact PNGB⇒ η no potential, only derivative couplings
• Fermion couplings break global symm., generate potential and mass
J. Reuter Pseudo Axions in LHM LCWS 2005, 6
/.α?〈〈〈↑↓〉〉〉ω Properties of Pseudo Axions
• η EW singlet
• ξ = exp[
iFη
]exact PNGB⇒ η no potential, only derivative couplings
• Fermion couplings break global symm., generate potential and mass
• explicit symmetry breaking ⇒ mη and gηγγ independent⇒ axion boundsnot applicable
J. Reuter Pseudo Axions in LHM LCWS 2005, 6
/.α?〈〈〈↑↓〉〉〉ω Properties of Pseudo Axions
• η EW singlet
• ξ = exp[
iFη
]exact PNGB⇒ η no potential, only derivative couplings
• Fermion couplings break global symm., generate potential and mass
• explicit symmetry breaking ⇒ mη and gηγγ independent⇒ axion boundsnot applicable
• no new hierarchy problem⇒ mη . v ∼ 250 GeV
J. Reuter Pseudo Axions in LHM LCWS 2005, 6
/.α?〈〈〈↑↓〉〉〉ω Properties of Pseudo Axions
• η EW singlet
• ξ = exp[
iFη
]exact PNGB⇒ η no potential, only derivative couplings
• Fermion couplings break global symm., generate potential and mass
• explicit symmetry breaking ⇒ mη and gηγγ independent⇒ axion boundsnot applicable
• no new hierarchy problem⇒ mη . v ∼ 250 GeV
• η couplings an to SM particles v/F suppressed
• Branching ratios (BRs): dominant (tt,) bb, τ+τ−, . . .
Chiral Structure of Yukawa couplings in LHM with heavy SU(2) singlet T :
TTH O(vF )
T tH O(1)PL + O(vF )PR
ttH O(1)
TTη O(1)γ5
T tη O(1)PR + O(vF )PL
ttη O(vF )γ5
J. Reuter Pseudo Axions in LHM LCWS 2005, 6
/.α?〈〈〈↑↓〉〉〉ω The µ Model (Simple-Group Model)
• ”Moose”-like model Schmaltz (2004), Kilian/Rainwater/JR (2004)
• µ term explicitly breaks global symm. (→ MSSM)⇒ EWSB, no Fine-Tuning
• enlarged gauge group: SU(3)×U(1); globally U(3)→ U(2)
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/.α?〈〈〈↑↓〉〉〉ω The µ Model (Simple-Group Model)
• ”Moose”-like model Schmaltz (2004), Kilian/Rainwater/JR (2004)
• µ term explicitly breaks global symm. (→ MSSM)⇒ EWSB, no Fine-Tuning
• enlarged gauge group: SU(3)×U(1); globally U(3)→ U(2)
Φ1/2 = exp[±i
F2/1
F1/2Θ
] 00
F1/2
Θ =1√
F21 + F2
2
η 00 η
h∗
hT η
J. Reuter Pseudo Axions in LHM LCWS 2005, 7
/.α?〈〈〈↑↓〉〉〉ω The µ Model (Simple-Group Model)
• ”Moose”-like model Schmaltz (2004), Kilian/Rainwater/JR (2004)
• µ term explicitly breaks global symm. (→ MSSM)⇒ EWSB, no Fine-Tuning
• enlarged gauge group: SU(3)×U(1); globally U(3)→ U(2)
Φ1/2 = exp[±i
F2/1
F1/2Θ
] 00
F1/2
Θ =1√
F21 + F2
2
η 00 η
h∗
hT η
Scalar Potential (κ ≡ F1/F2 + F2/F1 > 2):
−V = −(δm2 + µ2κ)(h†h) − µ2κη2
2+ (
µ2κ2
12F1F2− δλ)(h†h)2 + . . .
δm, δλ 1-loop contributions (Coleman-Weinberg Potential)
mη =√
κ µ >√
2 µ no Fine-tuning: µ ∼ v m2H = −2(δm2 + m2
η)
J. Reuter Pseudo Axions in LHM LCWS 2005, 7
/.α?〈〈〈↑↓〉〉〉ω The µ Model (Simple-Group Model)
Left: F1/F2 = 1, 1/2, 1/4, 1/6 Middle: fixed F2 = 2.0 TeV. Right: fixed F1/F2 = 1/4, various F1 [TeV]: 0.5, 1.0, 1.5, 2.0
(—, − − −, − ·−·, · · · , resp.)
J. Reuter Pseudo Axions in LHM LCWS 2005, 8
/.α?〈〈〈↑↓〉〉〉ω The µ Model (Simple-Group Model)
Left: F1/F2 = 1, 1/2, 1/4, 1/6 Middle: fixed F2 = 2.0 TeV. Right: fixed F1/F2 = 1/4, various F1 [TeV]: 0.5, 1.0, 1.5, 2.0
(—, − − −, − ·−·, · · · , resp.)
• heavy partners for SM fermions (ΨL = (tL, bL, TL)T )
L = − λt1t1,RΦ
†1ΨT ,L − λt
2t2,RΦ†2ΨT ,L −
λb
Λεijkqb
RΦi1Φ
j2Ψ
kT ,L
− λd1 qd
1,RΦ†1ΨQ,L − λd
2 qd2,RΦ
†2ΨQ,L −
λu
Λεijkqu
RΦi1Φ
j2Ψ
kQ,L + · · ·+ h.c.
J. Reuter Pseudo Axions in LHM LCWS 2005, 8
/.α?〈〈〈↑↓〉〉〉ω The µ Model (Simple-Group Model)
Left: F1/F2 = 1, 1/2, 1/4, 1/6 Middle: fixed F2 = 2.0 TeV. Right: fixed F1/F2 = 1/4, various F1 [TeV]: 0.5, 1.0, 1.5, 2.0
(—, − − −, − ·−·, · · · , resp.)
• heavy partners for SM fermions (ΨL = (tL, bL, TL)T )
L = − λt1t1,RΦ
†1ΨT ,L − λt
2t2,RΦ†2ΨT ,L −
λb
Λεijkqb
RΦi1Φ
j2Ψ
kT ,L
− λd1 qd
1,RΦ†1ΨQ,L − λd
2 qd2,RΦ
†2ΨQ,L −
λu
Λεijkqu
RΦi1Φ
j2Ψ
kQ,L + · · ·+ h.c.
• Assumptions: no mixing between SM and heavy fermions in 1./2. family,minimal MT (LHC)
J. Reuter Pseudo Axions in LHM LCWS 2005, 8
/.α?〈〈〈↑↓〉〉〉ω Parameters and all that...
• free parameters: F1,2 and µ with√
F21 + F2
2 & 2 TeV [∆T , Contact IA]F1 & v, F2 > F1 (Fermion mixing/universality)
J. Reuter Pseudo Axions in LHM LCWS 2005, 9
/.α?〈〈〈↑↓〉〉〉ω Parameters and all that...
• free parameters: F1,2 and µ with√
F21 + F2
2 & 2 TeV [∆T , Contact IA]F1 & v, F2 > F1 (Fermion mixing/universality)
“Golden Point” (fulfills EW precision and flavor limits):F1 = 0.5 TeV mD,S = 0.7 TeVF2 = 2 TeV mZ′ = 1.2 TeVΛ = 5 TeV mW ′ = 0.95 TeV
mT = 1 TeV
J. Reuter Pseudo Axions in LHM LCWS 2005, 9
/.α?〈〈〈↑↓〉〉〉ω Parameters and all that...
• free parameters: F1,2 and µ with√
F21 + F2
2 & 2 TeV [∆T , Contact IA]F1 & v, F2 > F1 (Fermion mixing/universality)
“Golden Point” (fulfills EW precision and flavor limits):F1 = 0.5 TeV mD,S = 0.7 TeVF2 = 2 TeV mZ′ = 1.2 TeVΛ = 5 TeV mW ′ = 0.95 TeV
mT = 1 TeV
ZHη coupling: LZHη ∝ mZ√2F
Zµ(η∂µH − H∂µη)
N.B.: v/F suppression compensated!
η analogous to A in 2HDM for small tan β = F1/F2 < 1 (flavor)
J. Reuter Pseudo Axions in LHM LCWS 2005, 9
/.α?〈〈〈↑↓〉〉〉ω η Branching Ratios
gg
bb
µ+µ−
cc
τ+τ−
γγ
Zh
50 100 150 200 250 300
10−4
0.001
0.01
0.1
1
mη [GeV]
BR [η]
J. Reuter Pseudo Axions in LHM LCWS 2005, 10
/.α?〈〈〈↑↓〉〉〉ω η Branching Ratios
gg
bb
µ+µ−
cc
τ+τ−
γγ
Zh
50 100 150 200 250 300
10−4
0.001
0.01
0.1
1
mη [GeV]
BR [η]new Higgs decays (H→ Zη, H→ ηη)
BR(H→ ηη) < 10−4 [∼ 5 − 10% OSG]
mH[GeV] mη[GeV] BR(Zη)341 223 0.1 %375 193 0.5 %400 167 0.8 %422 137 1.0 %444 96 1.2 %464 14 1.4 %
J. Reuter Pseudo Axions in LHM LCWS 2005, 10
/.α?〈〈〈↑↓〉〉〉ω Production at LHC
• Gluon Fusion (axial U(1)η
anomaly) (analogous togg→ H→ γγ cf. ATLAS/CMS TDR )
• v/F-suppression in the loopcompensated!
• Cross section large for F1 � F2
J. Reuter Pseudo Axions in LHM LCWS 2005, 11
/.α?〈〈〈↑↓〉〉〉ω Production at LHC
• Gluon Fusion (axial U(1)η
anomaly) (analogous togg→ H→ γγ cf. ATLAS/CMS TDR )
• v/F-suppression in the loopcompensated!
• Cross section large for F1 � F2
• ”Golden Point” LHC(300 fb−1):mη ∼ 320 GeV 7σ
5σ for mη = 240 GeV(SLHC up to mη = 130 GeV)S : B ∼ 1/10 − 1/50
• NLO cross sections; diphoton Bkgd.(Diphox Binoth); pT (γ) > 40 GeV,|ηγ| < 2.5, εγ = 0.8
J. Reuter Pseudo Axions in LHM LCWS 2005, 11
/.α?〈〈〈↑↓〉〉〉ω Pseudo Axions at the Linear Collider
ttη associated production Problem: Cross section vs. bkgd.
J. Reuter Pseudo Axions in LHM LCWS 2005, 12
/.α?〈〈〈↑↓〉〉〉ω Pseudo Axions at the Linear Collider
ttη associated production Problem: Cross section vs. bkgd.
0.50.2
gttη = 0.1
σtot [fb]
0.001
0.01
0.1
1
0 100 200 300 400 500
e+e− → ttη
√s = 1 TeV
mη [GeV]
J. Reuter Pseudo Axions in LHM LCWS 2005, 12
/.α?〈〈〈↑↓〉〉〉ω Pseudo Axions at the Linear Collider
ttη associated production Problem: Cross section vs. bkgd.
0.50.2
gttη = 0.1
σtot [fb]
0.001
0.01
0.1
1
0 100 200 300 400 500
e+e− → ttη
√s = 1 TeV
mη [GeV]
e−e+ → ttbb
#evt/2 GeV
√s = 800 GeV∫L = 1 ab−1
gttη = 0.2
0 50 100 150
10
100
1000
104
Minv(bb) [GeV]
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/.α?〈〈〈↑↓〉〉〉ω Pseudo Axions at the Linear Collider
ttη associated production Problem: Cross section vs. bkgd.
0.50.2
gttη = 0.1
σtot [fb]
0.001
0.01
0.1
1
0 100 200 300 400 500
e+e− → ttη
√s = 1 TeV
mη [GeV]
e−e+ → ttbb
#evt/2 GeV
√s = 800 GeV∫L = 1 ab−1
gttη = 0.2
0 50 100 150
10
100
1000
104
Minv(bb) [GeV]
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/.α?〈〈〈↑↓〉〉〉ω Pseudo Axions at the Linear Collider
ttη associated production Problem: Cross section vs. bkgd.
0.50.2
gttη = 0.1
σtot [fb]
0.001
0.01
0.1
1
0 100 200 300 400 500
e+e− → ttη
√s = 1 TeV
mη [GeV]
e−e+ → ttbb
#evt/2 GeV
√s = 800 GeV∫L = 1 ab−1
gttη = 0.2
mη = 50 GeV100
150
0 50 100 150
10
100
1000
104
Minv(bb) [GeV]
Possibility: Z∗ → Hη (analogous to A in 2HDM) Kilian/JR/Rainwater (in prep.)
J. Reuter Pseudo Axions in LHM LCWS 2005, 12
/.α?〈〈〈↑↓〉〉〉ω Pseudo Axions at the Photon Collider
• Photon Collider as precision ma-chine for Higgs physics (s chan-nel resonance, anomaly cou-pling)
• S/B analogous to LC
• η in the µ model with (almost)identical parameters as A inMSSM( ↪→ Muhlleitner et al. (2001) )
J. Reuter Pseudo Axions in LHM LCWS 2005, 13
/.α?〈〈〈↑↓〉〉〉ω Pseudo Axions at the Photon Collider
• Photon Collider as precision ma-chine for Higgs physics (s chan-nel resonance, anomaly cou-pling)
• S/B analogous to LC
• η in the µ model with (almost)identical parameters as A inMSSM( ↪→ Muhlleitner et al. (2001) )
H (SM)H (with T )η [T ]η [1 complete heavy gen.]η [3 gen. of heavy quarks]η [3 complete heavy gen.]
σeff(γγ→ η, H) [pb]
100 200 300 400 500 600 700
0.001
0.01
0.1
1
10
mH, mη [GeV]
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/.α?〈〈〈↑↓〉〉〉ω Pseudo Axions at the Photon Collider
gbbη = 0.4 · gbbhmη 100 130 200 285
Γγγ[keV] 0.15 0.27 1.1 3.6
J. Reuter Pseudo Axions in LHM LCWS 2005, 14
/.α?〈〈〈↑↓〉〉〉ω Pseudo Axions at the Photon Collider
gbbη = 0.4 · gbbhmη 100 130 200 285
Γγγ[keV] 0.15 0.27 1.1 3.6
γγ→ (H, η)→ bb
#evt/2 GeV
√see = 200 GeV∫Lee = 400 fb−1
| cos(θ)T | < 0.76
|pz|/√
see < 0.1
80 100 120 140 1600
200
400
600
800
1000
1200
1400
Minv(bb) [GeV]
γγ→ (H, η)→ bb
#evt/2 GeV
√see = 500 GeV∫Lee = 1 ab−1
| cos(θ)T | < 0.76
|pz|/√
see < 0.04
100 200 300 400
10
100
1000
104
Minv(bb) [GeV]
J. Reuter Pseudo Axions in LHM LCWS 2005, 14
/.α?〈〈〈↑↓〉〉〉ω Pseudo Axions at the Photon Collider
gbbη = 0.4 · gbbhmη 100 130 200 285
Γγγ[keV] 0.15 0.27 1.1 3.6
γγ→ (H, η)→ bb
#evt/2 GeV
√see = 200 GeV∫Lee = 400 fb−1
| cos(θ)T | < 0.76
|pz|/√
see < 0.1
80 100 120 140 1600
200
400
600
800
1000
1200
1400
Minv(bb) [GeV]
γγ→ (H, η)→ bb
#evt/2 GeV
√see = 500 GeV∫Lee = 1 ab−1
| cos(θ)T | < 0.76
|pz|/√
see < 0.04
100 200 300 400
10
100
1000
104
Minv(bb) [GeV]
J. Reuter Pseudo Axions in LHM LCWS 2005, 14
/.α?〈〈〈↑↓〉〉〉ω Pseudo Axions at the Photon Collider
gbbη = 0.4 · gbbhmη 100 130 200 285
Γγγ[keV] 0.15 0.27 1.1 3.6
γγ→ (H, η)→ bb
#evt/2 GeV
√see = 200 GeV∫Lee = 400 fb−1
| cos(θ)T | < 0.76
|pz|/√
see < 0.1mη =
100 GeV
130
80 100 120 140 1600
200
400
600
800
1000
1200
1400
Minv(bb) [GeV]
γγ→ (H, η)→ bb
#evt/2 GeV
√see = 500 GeV∫Lee = 1 ab−1
| cos(θ)T | < 0.76
|pz|/√
see < 0.04mη = 200 GeV
285
100 200 300 400
10
100
1000
104
Minv(bb) [GeV]
J. Reuter Pseudo Axions in LHM LCWS 2005, 14
/.α?〈〈〈↑↓〉〉〉ω Conclusions
♦ Little Higgs elegant alternative to SUSY
ungauged, anomalous U(1)η: new singlet (pseudo-)scalars η
• massive Z ′ (easily detectable)←→ η physical (difficult)
• Explicit symmetry breaking circumvents axion limits
• LHC: η production in gluon fusion, diphoton signal
• Pseudo axions change T phenomenology!
• ILC: tt associated production (mη small), Z∗ → Hη
Photon Collider: all masses, complementary measurement
J. Reuter Pseudo Axions in LHM LCWS 2005, 15