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Strong dynamics as an origin of the light Higgs boson and BSM phenomena
Kei Yagyu
2019, 18th June, Osaka U
Collaboration with S. De Curtis, L. Delle Rose (U. of Florence),
S. Moretti (U. of Southampton), R. Nagai (ICRR → U. of Padua)
1
Meet Joe Black
A story about a Death (死神)
Directed by Martin Brest, 1998
People knows his name, voice and face,
but does not really know “who he is”….
2
Meet Higgs boson
We know the mass, spin and parity
of the Higgs boson, but do not know
“who Higgs is”.
In 2012
In the Standard ModelThe Higgs boson is introduced as an elementary scalar field Φ(x).
Assuming μ2 < 0 and λ > 0, we obtain the
“wine bottle” type potential.
In the Standard ModelThe Higgs boson is introduced as an elementary scalar field Φ(x).
Assuming μ2 < 0 and λ > 0, we obtain the
“wine bottle” type potential.
yψL
ψR
v
g2V
V
v
v
λh
h
v
v
The SM Higgs sector works well to describe
the origin of masses,
but it is just a parametrization of the EWSB
in the economical way….
Questions in the SM Higgs sector
What is the origin of the negative μ2?
What is the origin of Yukawa couplings?
What is the true structure of the Higgs sector?
Questions in the SM Higgs sector
What is the origin of the negative μ2?
What is the origin of Yukawa couplings?
What is the true structure of the Higgs sector?
Why can the Higgs boson be so light?
Energy
100 GeV 1019 GeV
Higgs boson mass
mh
Planck
Λ = 1 TeV → c = 1 (say 100 %)
Λ = 10 TeV → c = 0.01 (1 %)
Λ = 1019 GeV → c = 10-32 (10-30 %)
EW
Energy
100 GeV 1019 GeV
Higgs boson mass
mh MP
103-4 GeV
BSM(No Λ2)
Scalar boson (Supersymmetry) : Chiral Symmetry
Fermion (Compositeness) : Chiral Symmetry
Gauge boson (Gauge-Higgs Unification): Gauge Symmetry
Higgs is
To know “who is the Higgs boson” is to know what is the BSM!!
Plan of Talk
I. Introduction
II. Composite Higgs Models
- Higgs as a pseudo Nambu-Goldstone boson (pNGB)
- Minimal Composite Higgs Model
III. CHMs with Non-Minimal Higgs Sectors
IV. Summary
Nambu-Goldstone bosons
Global symmetry breaking︓G → H
G
H
Rotation:
Broken generators︓
Nambu-Goldstoneʼs theorem:
One broken generator corresponds to
one massless NG boson Rotation by UNGB
Are there any NGBs as physical degrees of freedom in Nature?
Energy
Λ=4πf
f
q q
π
ρ1 GeV
0.1 GeV
9/35
Pion and Composite Higgs Georgi, Kaplan (1984)Contino, Nomura, Pomarol (2003)
QCD(no scalar)
G = SU(2)L × SU(2)R
H = SU(2)V
Non-pert. effects
Energy
Λ=4πf
f
q q
π
ρ1 GeV
0.1 GeV
×1000
9/35
Pion and Composite Higgs
QCD(no scalar)
Georgi, Kaplan (1984)Contino, Nomura, Pomarol (2003)
Energy
1 TeV
0.1 TeV
ψ ψ
h
W ,̓ Zʼ?
Energy
Λ=4πf
f
q q
π
ρ1 GeV
0.1 GeV
Λ=4πf
f
QCD-like Th.
×1000
9/35
Pion and Composite Higgs
H
Non-pert. effects
G
QCD(no scalar)
Georgi, Kaplan (1984)Contino, Nomura, Pomarol (2003)
Energy
1 TeV
0.1 TeV
ψ ψ
h
W ,̓ Zʼ?
Energy
Λ=4πf
f
q q
π
ρ1 GeV
0.1 GeV
Λ=4πf
f
QCD-like Th.
×1000
No discovery, Exc. by EWPT
☹
9/35
Pion and Composite Higgs
QCD(no scalar)
Georgi, Kaplan (1984)Contino, Nomura, Pomarol (2003)
H
Non-pert. effects
G
Energy
ψ ψ
h
W ,̓ Zʼ?
Energy
Λ=4πf
f
q q
π
ρ1 GeV
0.1 GeV
Λ=4πf
f
QCD-like Th.
×10000
9/35
Pion and Composite Higgs
10 TeV
1 TeV
Too heavy
☹Heavy enough
☺
QCD(no scalar)
Georgi, Kaplan (1984)Contino, Nomura, Pomarol (2003)
H
Non-pert. effects
G
Energy
ψ ψ
h
W ,̓ Zʼ?
Energy
Λ=4πf
f
q q
π
ρ
QCD(no scalar)
1 GeV
0.1 GeV
Λ=4πf
f
QCD-like Th.
×10000
9/35
Pion and Composite Higgs
10 TeV
1 TeV
0.1 TeV v ~ f/4π
Vacuum Misalignment
Georgi, Kaplan (1984)Contino, Nomura, Pomarol (2003)
H
Non-pert. effects
G
Mrazek et al, NPB 853 (2011) 1-48
G [dim] H [dim] Higgs sector
SO(5) [10] SO(4) [6] Φ
SO(6) [15] SO(5) [10] Φ + S
SO(6) [15] SO(4)×SO(2) [7]SU(5) [24] SU(4)×U(1) [16] Φ + ΦʼSp(6) [21] Sp(4)×SU(2) [13]
SU(5) [24] SO(5) [10] Φ + Δ + Setc
Agashe, Contino, Pomarol (2005)
16/35
G
H
G
f
vEM
The structure of the Higgs sector is determined by the coset G/H.
H should contain the custodial SO(4) ≃ SU(2)L×SU(2)R symmetry.
The number of NGBs (dimG-dimH) must be 4 or lager.
Explicit breaking of G must be introduced.
Basic Rules for the Construction
sm
Minimal Composite Higgs Model
G/H = SO(5)/SO(4): 4NGBs SO(4) ≃ SU(2)L × SU(2)R
SU(2)L × SU(2)R
TΦ transforms as the SU(2) bidoublet
10 SO(5) generators:
Agashe, Contino, Pomarol (2005)
10 6
NGB Matrix
Linear Rep.
Minimal Composite Higgs Model
Kinetic Lag.
Higgs couplings
Gauge boson mass
Custodial symmetry!
Agashe, Contino, Pomarol (2005)
Higgs Potential
Due to the shift symmetry of the NGB, the Higgs potential is 0 at any order of perturbation. → Higgs boson is massless.
We need to introduce an explicit breaking of G. → Higgs becomes pseudo-NGB with a finite mass.
Explicit breaking can be introduced via partial compositeness mechanism.Kaplan, PLB365, 259 (1991)
Elementary sector(SM particles) Strong sector particles
Linear mixing
Potential =
Vacuum misalignment
The Higgs potential is written as
Vacuum condition (Vʼ = 0)
GeV4
Vacuum missalignment
The Higgs potential is written as
Vacuum condition (Vʼ = 0)
Higgs Mass (Vʼʼ)
The light Higgs boson is naturally explained by an O(1) coefficient.
α and β can be predicted from strong dynamics.
Structure of the CHMs
Elementary Sector Strong Sector
Mixing
Partial CompositenessGsm = SU(2)L×U(1)Y
G → H
Integrate ρ and ψ out
G
SM particles are embedded
SO(5)×U(1)X Model︓Fermion SectorDe Curtis, Redi, Tesi, JHEP04 (2012) 042
Elementary Sector Strong Sector
Gsm = SU(2)L×U(1)Y
SO(5)×U(1)X SO(5)×U(1)X
SO(4)×U(1)X
Σ
We take SO(5) 5-plet for the fermion representation.
X=2/3X=2/3
4=2×2
1
4=2×2
1
SO(5)×U(1)X Model︓Fermion SectorDe Curtis, Redi, Tesi, JHEP04 (2012) 042
Elementary Sector Strong Sector
Gsm = SU(2)L×U(1)Y
SO(5)×U(1)X SO(5)×U(1)X
SO(4)×U(1)X
Σ
We take SO(5) 5-plet for the fermion representation.
X=2/3X=2/3
(+ LL-term + RR-term)
2-site model
Effective Lagrangian︓Fermion Sector
The Higgs potential can be calculated as
Effective Potential
(+ LL-term + RR-term)
Higgs boson mass
Lightest extra fermion mass [GeV]
f = 800 GeV, mρ = 2.5 TeV
De Curtis, Redi, Tesi, JHEP04 (2012) 042
Plan of Talk
I. Introduction
II. Composite Higgs Models
- Higgs as a pseudo Nambu-Goldstone boson (pNGB)
- Minimal Composite Higgs Model
III. CHMs with Non-Minimal Higgs Sectors
IV. Summary
Energy
ψ ψ
h
W ,̓ Zʼ?
Energy
Λ=4πf
f
q q
π
ρ
QCD(no scalar)
1 GeV
0.1 GeV
Λ=4πf
f
QCD-like Th.
9/35
Pion and Composite Higgs
10 TeV
1 TeV
0.1 TeVv ~ f/4π
Georgi, Kaplan (1984)Contino, Nomura, Pomarol (2003)
SO(4)
SO(5)
SU(2)V
SU(2)L × SU(2)R
Energy
ψ ψ
h
W ,̓ Zʼ?
Energy
Λ=4πf
f
q q
π
ρ
QCD(no scalar)
1 GeV
0.1 GeV
Λ=4πf
f
QCD-like Th.
9/35
Pion and Composite Higgs
10 TeV
1 TeV
0.1 TeVv ~ f/4π
Georgi, Kaplan (1984)Contino, Nomura, Pomarol (2003)
K, η
SO(4)
SO(5)
SU(3)V
SU(3)L × SU(3)R
Energy
ψ ψ
h
W ,̓ Zʼ?
Energy
Λ=4πf
f
q q
π
ρ
QCD(no scalar)
1 GeV
0.1 GeV
Λ=4πf
f
QCD-like Th.
9/35
Pion and Composite Higgs
10 TeV
1 TeV
0.1 TeVv ~ f/4π
Georgi, Kaplan (1984)Contino, Nomura, Pomarol (2003)
K, η
H, H±, …Hʼ
Gʼ
SU(3)V
SU(3)L × SU(3)R
Energy
ψ ψ
h
W ,̓ Zʼ?
Energy
Λ=4πf
f
q q
π
ρ
QCD(no scalar)
1 GeV
0.1 GeV
Λ=4πf
f
QCD-like Th.
9/35
Pion and Composite Higgs
10 TeV
1 TeV
0.1 TeVv ~ f/4π
Georgi, Kaplan (1984)Contino, Nomura, Pomarol (2003)
K, η, …
H, H±, …
・Higgs phenomenology
・Neutrino masses・Dark matter ・Baryon asymmetry (CPV)
S. De Curtis, R. Nagai and KY (in progress)
S. De Curtis, L. Delle Rose, S. Moretti and KY
1803.01865 (PLB) & 1810.06465 (JHEP)
Mrazek et al, NPB 853 (2011) 1-48
G [dim] H [dim] Higgs sector
SO(5) [10] SO(4) [6] Φ
SO(6) [15] SO(5) [10] Φ + S
SO(6) [15] SO(4)×SO(2) [7]SU(5) [24] SU(4)×U(1) [16] Φ + ΦʼSp(6) [21] Sp(4)×SU(2) [13]
SU(5) [24] SO(5) [10] Φ + Δ + Setc
Agashe, Contino, Pomarol (2005)
16/35
G
H
G
f
vEM
The structure of the Higgs sector is determined by the coset G/H.
H should contain the custodial SO(4) ≃ SU(2)L×SU(2)R symmetry.
The number of NGBs (dimG-dimH) must be 4 or lager.
Explicit breaking of G must be introduced.
Basic Rules for the Construction
sm
Composite 2HDM(C2HDM)
SO(6) generators (15): (A=1-15, a=1-3, a=1-4)^
6 SO(4) 1 SO(2) 8 Broken
G→H: SO(6) × U(1)X → SO(4) × SO(2) × U(1)X
NGB Mat.:
2 Higgs Doublets
De Curtis, Delle Rose, Moretti, KY, arXiv: 1803.01865 [hep-ph] (PLB)
15-plet︓
Setup for C2HDM
We introduce SO(6) 6-plet fermions for the explicit Lagrangian:
Z2-like symmetry in the strong sector can be introduced.
C2 symmetry(to avoid FCNCs) C2 = diag(1,1,1,1,1,-1)
Setup for C2HDM
Z2-like symmetry in the strong sector can be introduced.
C2 symmetry(to avoid FCNCs) C2 = diag(1,1,1,1,1,-1)
1. Unbroken case, 2. Spontaneously broken case and 3. Hardly broken case(there is no option for the softly-breaking)
We introduce SO(6) 6-plet fermions for the explicit Lagrangian:
CP-Violation
CP-violation in the strong sector
Yukawa interactions Higgs potentialCorrelations
EDMs Higgs couplings & decays
test test
S. De Curtis, R. Nagai and KY (work in progress)
T parameter SO(6)/SO(4)×SO(2) model
f > O(10 TeV) for O(1) tanβ, α and arg(v2).
O(10-3)
Aμ: SO(6) adjoint gauge boson, Σ: SO(6) adjoint pNGB
SO(9)/SO(8) model Aμ: SO(9) adjoint gauge boson, Σ: SO(9) 9-plet pNGB
S. De Curtis, R. Nagai and KY (work in progress)
With CP-conservation
The effective potential is formally written as
Effective Potential
Gauge loop contributions
No EWSB and no Z2 breaking.
+ O(Φ6)
The effective potential is formally written as
+ O(Φ6)
Effective Potential
Fermion loop contributions
m12 and m2
2 can be negative → EWSB.
Typical Prediction of Mass Spectrum
h ~ 125 GeV
H±, H, A
f ~ TeV
Ψ, ρμ
E
Y1: C2 breaking term
Typical Prediction of Mass Spectrum
h ~ 125 GeV
H±, H, A
f ~ TeV
Ψ, ρμ
E
Y1: C2 breaking term
★f ∞ : All extra Higgses are decoupled (elementary) SM limit
★To get M≠0, we need C2 breaking (Yukawa alignment is required).
Correlation b/w f and mADe Curtis, Delle Rose, Moretti, KY, arXiv: 1803.01865 [hep-ph]
Correlation b/w mA and κV (= ghVV/ghVVSM)
MSSM: FeynHiggs v2.14.1
De Curtis, Delle Rose, Moretti, KY, arXiv: 1803.01865 [hep-ph]
Summary
The CHMs are one of the attractive candidates for new physics to
naturally explain the light Higgs mass.
The Higgs potential is predicted by setting a strong sector Lagrangian.
Non-minimal CHMs can be applied to explain BSM phenomena.
Rich phenomenological consequences are obtained which can be quite
different from the other scenarios such as SUSY, E2HDMs, and so on.
49
Slide from M. Peskin @HPNP2015
50
Slide from Csaba Csaki
51
Slide from Csaba Csaki
Correlation b/w mA and mass differencesDe Curtis, Delle Rose, Moretti, KY, arXiv: 1803.01865 [hep-ph]
MSSM: FeynHiggs v2.14.1
SO(5)×U(1)X Model︓Gauge sectorDe Curtis, Redi, Tesi, JHEP04 (2012) 042
Elementary Sector Strong Sector
Gsm = SU(2)L×U(1)Y
SO(5)×U(1)X
U1
SO(5)L ×SO(5)R → SO(5)V (10 NGBs)~1
SO(5) → SO(4) (4 NGBs)~Σ0
SO(5)×U(1)X
SO(4)×U(1)X
Σ2
14 NGBs = 10 massive ρ and 4 pNGB Higgs
SO(5)×U(1)X Model︓Gauge sectorDe Curtis, Redi, Tesi, JHEP04 (2012) 042
Elementary Sector Strong Sector
Gsm = SU(2)L×U(1)Y
SO(5)×U(1)X
U1
SO(5)×U(1)X
SO(4)×U(1)X
Σ2
+ A-ρ mixing
Effective Lagrangian︓Gauge sector
2-site model
Expand at p2 ~ 0
S, T parameterPanico, Wulzer, arXiv:1506.01961
Contribution from modified Higgs couplings (1-loop)
Here, Λ = mρ = 3 TeV
ξ = v2/f2 <
ξ = v2/f2
ξ < 0.05 @2σ (0.08 @3σ) f < 1.1TeV @2σ (870 GeV @3σ)
S, T parameterPanico, Wulzer, arXiv:1506.01961
Contribution from heavy resonances
yL = ΔL/f , m : lightest fermion partner mass
G1 × G2 × G3
U1(15=7+8) Σ2(8)GVʼ(gauged)
GVH [SO(4)×SO(2)]
Gi : Global SO(6)
8 + 8(Φ1, Φ2)
mixed
Gauge Sector Lagrangian
7 + 8 NGBs are absorbed into the longitudinal components of gauge bosons of adj[SO(6)].
De Curtis, Redi, Tesi, JHEP04 (2012) 042
59
Naïve Dimensional Analysis
General 2 Higgs Doublet Model
SM + one additional iso-doublet scalar︓Φ1 + Φ2
Physical Higgs bosons︓8-3=5 : H± , A , H, h (125 GeV)
Most general Higgs potential under SU(2)L×U(1)Y
Charged CP-odd CP-even
2 VEVs:
General 2 Higgs Doublet Model
SM + one additional iso-doublet scalar︓Φ1 + Φ2
Physical Higgs bosons︓8-3=5 : H± , A , H, h (125 GeV)
Most general Higgs potential under SU(2)L×U(1)Y with softly-broken Z2 +CPC
Charged CP-odd CP-even
2 VEVs:
m2 and λ can be determined by new physics dynamics, e.g., λ ~ g2 in SUSY.
Effective Lagrangian
Integrating out the heavy degrees of freedom (ρA and ψ6), we obtain the effective low energy Lagrangian
≔ G ≔ K
Effective Lagrangian
Integrating out the heavy degrees of freedom (ρA and ψ6), we obtain the effective low energy Lagrangian
≔ G ≔ K
These coefficients can be expanded as
c1, c2, … are determined by strong parameters.
Matching Conditions
We need to reproduce the top mass and the weak boson mass.
g2 Vsm2 ~ (246 GeV)2
Yt
SO(5)×U(1)X Model︓Fermion SectorDe Curtis, Redi, Tesi, JHEP04 (2012) 042
Elementary Sector Strong Sector
Gsm = SU(2)L×U(1)Y
SO(5)×U(1)X
U1
SO(5)×U(1)X
SO(4)×U(1)X
Σ2
We take SO(5) 5-plet for the fermion representation.
X=2/3X=2/3
4=2×2
1
4=2×2
1
Elementary Sector Strong Sector
Gsm = SU(2)L×U(1)Y
SO(5)×U(1)X
U1
SO(5)×U(1)X
SO(4)×U(1)X
Σ2X=2/3X=2/3
2 flavour case (I, J=1,2) → Minimal choice for
UV div. free potential.
21/35
We take SO(5) 5-plet for the fermion representation.
SO(5)×U(1)X Model︓Fermion SectorDe Curtis, Redi, Tesi, JHEP04 (2012) 042
Elementary Sector Strong Sector
Gsm = SU(2)L×U(1)Y
SO(5)×U(1)X
U1
SO(5)×U(1)X
SO(4)×U(1)X
Σ2X=2/3X=2/3
21/35
We take SO(5) 5-plet for the fermion representation.
SO(5)×U(1)X Model︓Fermion SectorDe Curtis, Redi, Tesi, JHEP04 (2012) 042
68
なぜデカップリングがSUSYより遅いか。 Βが正でなければならない理由は何か。 なぜMT1が軽いところにでるのか。
Q. When the 2HDM is realized as EFT…
Properties of the 2HDM tell us the direction!
SUSY︖ex. MSSM
Composite (pNGB)︖ex. SO(6) → SO(4) × SO(2)
or
f VS tanβ De Curtis, Delle Rose, Moretti, KY, arXiv: 1803.01865 [hep-ph]
Masses of heavy top partners
C2HDM MSSM
De Curtis, Delle Rose, Moretti, KY, arXiv: 1803.01865 [hep-ph]
MSSM: FeynHiggs v2.14.1
Numerical Analysis
Input parameters (to be scanned):
Tadpole conditions: T1 = T2 = 0
165 GeV < mt < 175 GeV
120 GeV < mh < 130 GeV