fingerprinting of the higgs boson couplings as a probe of new physics models
DESCRIPTION
Fingerprinting of the Higgs boson couplings as a probe of new physics models. Yagyu , Kei ( 柳生 慶 ) National Central U. Collaboration with Shinya Kanemura and Mariko Kikuchi (U. of Toyama) . Physics Letters B731, 27-35 (2014), arXiv:1401.0515 [ hep-ph ]. Academia Sinica , Mar. 7, 2014. - PowerPoint PPT PresentationTRANSCRIPT
Fingerprinting of the Higgs boson couplings as a probe of new physics models
Academia Sinica, Mar. 7, 2014
Yagyu, Kei ( 柳生 慶 ) National Central U.
Physics Letters B731, 27-35 (2014), arXiv:1401.0515 [hep-ph]
Collaboration with Shinya Kanemura and Mariko Kikuchi (U. of Toyama)
2
Cavity Radiation
In the end of 19th century, people thought that physics has already been completed by Newton’s dynamics and Maxwell’s electromagnetism.
However, there were a few phenomena which couldn’t be explained by classical physics such as the spectrum of cavity radiation.
Wien’s Low (1896)
Rayleigh-Jeans Low (1900)
Exp.
Wien’s Low
Rayleigh-Jeans Low
3
Cavity Radiation
In the end of 19th century, people thought that physics has already been completed by Newton’s dynamics and Maxwell’s electromagnetism.
However, there were a few phenomena which couldn’t be explained by classical physics such as the spectrum of cavity radiation.
Exp. ~ Planck’s Low
Wien’s Low
Rayleigh-Jeans Low
Planck’s Low (1905)
4
Paradigm Shift
Classical Theory
-Newton Dynamics-Maxwell Electromagnetism Planck’s Low
Einstein’s Light Quantum Hypothesis
Early 20th century
Cavity Radiation gave a “Bridge” connecting Classical Theory and Quantum Theory.
Quantum Theory
- Nuclear Physics- Particle Physics, …
Cavity Radiation
5
Gauge SectorG, W, Z, γ
Matter SectorQuarks & Leptons
Higgs SectorHiggs mechanism Yukawa interaction
Today
Gauge interaction
We have the Standard Model.
6
Gauge SectorG, W, Z, γ
Matter SectorQuarks & Leptons
Higgs SectorHiggs mechanism Yukawa interaction
Today
Gauge interaction
We have the Standard Model.
Well tested before the LHC
7
Gauge SectorG, W, Z, γ
Matter SectorQuarks & Leptons
Higgs SectorHiggs mechanism Yukawa interaction
Today
Gauge interaction
We have the Standard Model.
8
Gauge SectorG, W, Z, γ
Matter SectorQuarks & Leptons
Higgs SectorHiggs mechanism Yukawa interaction
Today
Gauge interaction
We have the Standard Model.
The LHC has found a Higgs boson with 126 GeV
9
Gauge SectorG, W, Z, γ
Matter SectorQuarks & Leptons
Higgs SectorHiggs mechanism Yukawa interaction
Today
Gauge interaction
We have the Standard Model.
However, still there are unclear things in the Higgs sector.
10
Next Paradigm Shift
New PhysicsStandard Model
Higgs Sector
EWSB
Today
Higgs Physics could give a next “Bridge” connecting the Standard Model and New Physics!
11
Three Questions
1. What is the true structure of the Higgs sector?
-Minimal or Non-minimal?
2. What is the dynamics behind the Higgs sector?
- Weak coupling or Strong coupling
3. How is the Higgs sector related to the phenomena
beyond the SM? - Neutrino oscillation, Dark matter, and Baryon asymmetry.
12
Three Questions
1. What is the true structure of the Higgs sector?
-Minimal or Non-minimal?
2. What is the dynamics behind the Higgs sector?
- Weak coupling or Strong coupling
3. How is the Higgs sector related to the phenomena
beyond the SM? - Neutrino oscillation, Dark matter, and Baryon asymmetry.
126 GeV Higgs
Explained
Minimal (1 doublet)
EW data,Flavor, …
13
ExtraSingletsDoubletsTriplets…
126 GeV Higgs
Explained
Minimal (1 doublet)
EW data,Flavor, …
14
Non-Minimal Higgs sectors
126 GeV Higgs
Introduce
Non-Minimal Higgs sectors
ExtraSingletsDoubletsTriplets…
Minimal (1 doublet)
New Physics ModelsNeutrino mass, Dark matter and Baryon asymmetry
Explained
EW data,Flavor, …
15
126 GeV Higgs
Determine
Higgs prop.
Determine
Non-Minimal Higgs sectors
ExtraSingletsDoubletsTriplets…
Minimal (1 doublet)
Neutrino mass, Dark matter and Baryon asymmetry
EW data,Flavor, …
16
New Physics Models
126 GeV Higgs
New Physics ModelsNeutrino mass, Dark matter and Baryon asymmetry
Determine
Higgs prop.
Determine
Non-Minimal Higgs sectors
ExtraSingletsDoubletsTriplets…
Minimal (1 doublet)
Bott
om u
p Ap
proa
ch!
EW data,Flavor, …
17
126 GeVh
H++, H+, H, A, ...h
2. Indirect search1. Direct search
H++, H+, H, A, …
Discovery
Studying both ways is important to determine the structure of the Higgs sector.
Bottom up Approach
126 GeV
EnergyEnergy
18
Measuring effects on the 126 GeV Higgs boson
126 GeVh
H++, H+, H, A, ...h
2. Indirect search1. Direct search
H++, H+, H, A, …
DiscoveryMeasuring effects on the 126 GeV Higgs boson
Studying both ways is important to determine the structure of the Higgs sector.
Bottom up Approach
126 GeV
EnergyEnergy
19
Indirect Search
Patterns of deviation in various Higgs couplings strongly depend on the structure of the Higgs sector.
Indirect search = Precision test of Higgs couplings
hbb
hττ
hcc
hγγ
hVV
hhhMake a “Fingerprint” from precise measurements.
Minimal Singlet Models2HDMsTriplet Modelsetc…
Compare
20
Experiments Theory
Higgs coupling measurements
21κV
κ F
κV = ghVV (exp)/ghVV (SM), κF = ghFF (exp)/ghFF (SM)
Scaling factors
ATLAS-CONF-2013-034 CMS-PAS-HIG-13-005
Higgs coupling measurements
22κV
κ F
κV = ghVV (exp)/ghVV (SM), κF = ghFF (exp)/ghFF (SM)
Scaling factors
ATLAS-CONF-2013-034 CMS-PAS-HIG-13-005
1
1.2
1.4
0.8
0.6The uncertainties for κF and κV are about ±40% and ±20%, respectively.
The hZZ coupling can be measured by 1 % accuracy at the ILC(250) !
Higgs coupling measurementsILC, TDRILC, Higgs White Paper, arXiv: 1310.0763
(300/fb)
23
The hVV and hff couplings can be measured by 1 % accuracy at the ILC(500) !!
Higgs coupling measurements(300/fb)
ILC, TDRILC, Higgs White Paper, arXiv: 1310.0763
24
The hVV and hff couplings can be measured by 1 % accuracy at the ILC(500) !!
Higgs coupling measurements(300/fb)
ILC, TDRILC, Higgs White Paper, arXiv: 1310.0763
25
Contents
Introduction- Bottom up approach (Indirect search)
Deviations in the Higgs boson couplings in various Higgs sectors- The hVV and hff couplings at the tree level
Higgs boson couplings in the 2HDMs - Tree level
- One-loop level Summery
26
1. Electroweak rho parameter
Basic ConstraintsThere are two guidelines to restrict Higgs sectors.
ρexp = 1.0004 -0.0004
+0.0003
Models with ρtree = 1 seems to be a natural choice. T Y1 01/2 1/23 2… …Alignment of (exotic) VEVs
Ex. Model with doublet (Y=1/2) + triplet (Y=1) + triplet (Y=0) (Georgi-Machacek model)
Satisfy the relation
if 27
2. Flavor Changing Neutral Current (FCNC)Tree level FCNC process should be absent. In general, multi-doublet extensions cause FCNC at the tree level
Basic ConstraintsThere are two guidelines to restrict Higgs sectors.
28
B0 Φ0B0
B0 Φ0B0
2. Flavor Changing Neutral Current (FCNC)Tree level FCNC process should be absent. In general, multi-doublet extensions cause FCNC at the tree level
Basic Constraints
Only one Higgs doublet couples to each fermion.
29
There are two guidelines to restrict Higgs sectors.
Simple Extended Higgs Sectors
We consider the following simple Higgs sectors; (with ρtree = 1 and no tree level FCNC)
1. Φ + S (Singlet)
2. Φ + D (Doublet)
3. Φ + Δ (Triplets or larger) [GM model, Septet model]
30
Hisano, Tsumura, PRD87 (2013)Kanemura, Kikuchi, KY, PRD88 (2013)
Two mixing angles
Mixing between CP-even states
VEVs
where
T: isospin, Y:hypercharge
31
Yukawa
Gauge
Deviations in hff and hVV
Φ
f
fφ
α
Yf = mf /<Φ> <φ> β
ΦV
V<Φ>
φ
V
V
<φ>
α
β
32
Yukawa
Gauge
Higgs Singlet Model (φ=S)
Φ
f
fS
α
Yf = mf /<Φ> <S>
ΦV
V<Φ>
α
★ The singlet VEV does not contribute to the EWSB. → β=∞ (<Φ>=246 GeV)
★ The hff and hVV couplings are universally suppressed.
33
S
<S>
Yukawa
Gauge
Two Higgs Doublet Model (φ=D)
Φ (D)
f
fD (Φ)
α
Yf = mf /<Φ (D)> <D (Φ)>
ΦV
V<Φ>
D
V
V
<D>
α
β
β★ There are 2 patterns in κf
for each fermion f.
★ ξ = 1
34
Yukawa
Gauge
Model with a triplet (or higher) (φ=Δ)
Φ
f
fΔ
α
Yf = mf /<Φ> <Δ>
ΦV
V<Φ>
Δ
V
V
<Δ> α
β
β
★ The hff couplings are universally suppressed.
★ ξ factor can be larger than unity. → κV > 1
35
Ex. GM model: ξ = 2*sqrt(6)/3 Septet model : ξ = 4
SM
36
SM
κF’
37
SM
κF’
κF = κF’
38
SM
κF’
κF = κF’
39
40
Gauge vs Yukawa
Singlet Model2HDM (Type-I)Georgi-Machacek Model [ξ = 2*Sqrt(6)/3]
Gauge vs Yukawa
-π/4 < α < +π/4 0.1 < tanβ < 100
Singlet Model2HDM (Type-I)Georgi-Machacek Model [ξ = 2*Sqrt(6)/3]
41
Contents
Introduction- Bottom up approach (Indirect search)
Deviations in the Higgs boson couplings in various Higgs sectors- The hVV and hff couplings at the tree level
Higgs boson couplings in the 2HDMs - Tree level
- One-loop level Summery
42
2HDMs
In general, Yukawa Lagrangian is given by
To avoid the tree level FCNC, one of the Yukawa couplings should be forbidden.
Z2 symmetry (softly-broken) Glashow, Weinberg, PRD15 (1977)
Z2 symmetry (unbroken) Barbieri, Hall, Rychkov, PRD74 (2006)
S3 symmetry Kajiyama, Okada, KY, arXiv:1309.6234 [hep-ph]
U(1) symmetry Ko, Omura, Yu, JHEP1201 (2012)
…
43
2HDMs with the softly-broken Z2 sym.
In general, Yukawa Lagrangian is given by
To avoid the tree level FCNC, one of the Yukawa couplings should be forbidden.
Z2 symmetry (softly-broken) Glashow, Weinberg, PRD15 (1977)
Z2 symmetry (unbroken) Barbieri, Hall, Rychkov, PRD74 (2006)
S3 symmetry Kajiyama, Okada, KY, arXiv:1309.6234 [hep-ph]
U(1) symmetry Ko, Omura, Yu, JHEP1201 (2012)
… There are four independent types of Yukawa interactions.
44
Barger, Hewett, Phillips (1990), Grossman (1994)
u
d
Φ 2
e
Φ 1
ud
Φ 2
e
u
d
Φ 2
eΦ 1
Type-I Type-II (MSSM)
ud
Φ 2
eΦ 1
Type-X(Leptophilic)
Type-Y(Flipped)
Aoki, Kanemura, Tsumura, KY (2008)
Four Yukawa InteractionsUnder the Z2 symmetry, two doublets are transformed as Φ1 → +Φ1 and Φ2 → -Φ2.
45
We define the Higgs basis by introducing β
tanβ = <Φ2>/<Φ1>
Mass Eigenstates
NG bosons Charged Higgs
CP-even Higgs CP-odd Higgs
SM-like Higgs boson w/126 GeV46
ξu ξd ξe
Type-I cotβ cotβ cotβType-II cotβ -tanβ -tanβType-X cotβ cotβ -tanβType-Y cotβ -tanβ cotβ
Yukawa/Gauge Interaction
hV
V= (SM) × sin(β-α)
h
f
f
= (SM) × [sin(β-α)+ξf cos(β-α)]
47
Higgs Potential The Higgs potential under the softly-broken Z2 sym. and CP-invariance
Mass formulae with sin(β-α) ~1
We have 8 parameters in the potential. They can be interpreted by
v (=246 GeV), mh (=126 GeV), mH, mA, mH+, sin(β-α), tanβ, and M2
mh2 ~ λv2, mΦ
2 ~ M2 + λv2
48
Φ = H±, A, H
SM-like/Decoupling Limit
SM-like limit: taking sin(β-α) → 1 All the Higgs boson couplings become the same value as in the SM Higgs couplings at the tree level.
Decoupling limit: taking M2 (=mΦ2) → ∞
Decoupling limit can be taken only when the SM-like limit is taken.
[mΦ2 ~ M2 + λv2]
49
Decoupling/SM-like Limit
Excluded
by unitarity
(mH = mA = mH+= M =)
10% dev.
1% dev.
0.1% dev.
cos(β-α) > 0
cos(β-α) < 0
50
δ =
Decoupling/SM-like Limit
Excluded
by unitarity
κV =
sin (β-α) → 1
(mH = mA = mH+= M =)
10% dev.
1% dev.
0.1% dev.
cos(β-α) > 0
cos(β-α) < 0
δ =
51
Decoupling/SM-like Limit
Excluded
by unitarity
(mH = mA = mH+= M =)
10% dev.
1% dev.
0.1% dev.
cos(β-α) > 0
cos(β-α) < 0
δ =
52
Patterns of Deviation in hff Couplings
h
f
f
= (SM) × [sin(β-α) + ξf cos(β-α)]
(SM) × [sin(β-α) + cotβ cos(β-α)]
(SM) × [sin(β-α) - tanβ cos(β-α)]
(SM) ×
(SM) ×
=
~ For cos(β-α) > 0 cos(β-α) < 0 δ ≪ 1
δ = 1 - sin(β-α)
If κV ≠ 1 is found, several patterns of deviation in hff appear.
ud
cotβe
Type-I
ud
cotβe
-tanβType-II
ud
cotβe
-tanβType-X
ud
cotβ
e-tanβ
Type-Y
53
Patterns of Deviation in hff Couplings
h
f
f
= (SM) × [sin(β-α) + ξf cos(β-α)]
(SM) × [sin(β-α) + cotβ cos(β-α)]
(SM) × [sin(β-α) - tanβ cos(β-α)]
(SM) ×
(SM) ×
=
~ For cos(β-α) > 0 cos(β-α) < 0 δ ≪ 1
δ = 1 - sin(β-α)
If κV ≠ 1 is found, several patterns of deviation in hff appear.
ud
cotβe
Type-I
ud
cotβe
-tanβType-II
ud
cotβe
-tanβType-X
ud
cotβ
e-tanβ
Type-Y
54
Bottom vs Tau
κV2 = 0.99, 0.95,
(δ ~ 0.005, 0.02)cos(β-α) < 0
55
• How these predictions can be modified by taking into account radiative corrections?
• The hff and hVV couplings can be measured with O(1)% accuracy.
Radiative Corrections
1-loop level
56
If α is the same order of the EM coupling, the correction is at most O(0.1)%. However, it can be larger than 1% due to nondecoupling effects of extra Higgs boson loops.
Radiative Corrections in the 2HDMs
There are papers for 1-loop corrections to the Higgs boson couplings in 2HDMs.
Hollik, Penaranda, Eur. Phys. J. C23 (2002) [in the MSSM Higgs sector]
Kanemura, Kiyoura, Okada, Senaha, Yuan PLB558, (2003);
Kanemura, Okada, Senaha, Yuan, PRD70 (2004).
hhh
hVV Kanemura, Okada, Senaha, Yuan, PRD70 (2004).
hff Guasch, Hollik, Penaranda, PLB515 (2001) [in the MSSM Higgs sector]
We discuss 1-loop corrections to the hff couplings in the four types of the 2HDM. 57
Decoupling/Nondecoupling
NP loop effects to the low energy obs. vanish when new particles are heavy.
Appelquist, Carazzone (1975)Decoupling theorem
1/Mn → 0 (M → ∞)
Violation of the decoupling theorem
SM
NP+SMM → ∞
SM
SM SM
SMSM
SM
Top mass : mt = ytv Scalar boson mass : mφ
2 = λv2 + M2 (with λv2 > M2 )
If a particle mass is (mostly) given by the Higgs VEV, the particle loop effect does not vanish even in rather large mass case.
E.g.,
58
The hhh coupling @1-loop in the 2HDM
Φ = H, A, H±
Kanemura, Kiyoura, Okada, Senaha, Yuan PLB558 (2003)
59
The hhh coupling @1-loop in the 2HDM
Φ = H, A, H±
In the case with M2 >> λv2,
we can see the decoupling behavior.
Kanemura, Kiyoura, Okada, Senaha, Yuan PLB558 (2003)
0
60
The hhh coupling @1-loop in the 2HDM
Φ = H, A, H±
Kanemura, Kiyoura, Okada, Senaha, Yuan PLB558 (2003)
~1
In the case with M2 < λv2,
nondecoupling effects (quartic power of the masses)appear.
61
Renormalized hff vertices Renormalized hff vertex
Renormalized scale factor at on-shell
The counter term contribution
62
Parameter Shifts
Fermion masses and wave functions
CP-even Higgs sector and mixing angle β
The VEV
Kanemura, Okada, Senaha, Yuan, PRD70 (2004).
63
On-shell Renormalization Conditions
= 0h Hp2=mh2
h H p2=mH2=
h h p2 =mh2= 0
f f p2=mf2= 0 f f p2=mf2
= 0
G0 A p2=mZ2=
G0 A p2=mA2= 0
δβ (and δCA)
δZh, δα and δCh
δmf and δZVf
The counter term δv is determined from the EW on-shell RCs.
Hollik, Fortsch. Phys. 38, 165 (1990).
64
1PI + C.T.
Decoupling [sin(β-α)=1, mH+=mA=mH (=mΦ) and mΦ
2-M2 = (300 GeV)2]
SM
Shinya Kanemura, Mariko Kikuchi and KY, PLB731, 2014
65
tanβ = 1tanβ = 3
Nondecoupling [sin(β-α)=1, mH+=mA=mH (=mΦ) and M2 = 0]
66
Shinya Kanemura, Mariko Kikuchi and KY, PLB731, 2014
Nondecoupling [sin(β-α)=1, mH+=mA=mH (=mΦ) and M2 = 0]
67
Shinya Kanemura, Mariko Kikuchi and KY, PLB731, 2014
Fingerprinting at the tree level
cos(β-α) < 0, tanβ = 1, 2, 3 and 4,
68
Shinya Kanemura, Mariko Kikuchi and KY, PLB731, 2014
Fingerprinting at the 1-loop level
cos(β-α) < 0, tanβ = 1, 2, 3 and 4, mH+ = mA = mH (=mΦ), 100 GeV < mΦ < 1 TeV, 0 < M < mΦ, Unitarity + Vacuum
stab.
69
Shinya Kanemura, Mariko Kikuchi and KY, PLB731, 2014
Fingerprinting at the 1-loop level
cos(β-α) < 0, tanβ: Scanned mH+ = mA = mH (=mΦ), 100 GeV < mΦ < 1 TeV, 0 < M < mΦ, Unitarity + Vacuum
stab.
70
Shinya Kanemura, Mariko Kikuchi and KY, PLB731, 2014
Fingerprinting at the 1-loop level
cos(β-α) < 0, tanβ: Scanned mH+ = mA = mH (=mΦ), 100 GeV < mΦ < 1 TeV, 0 < M < mΦ, Unitarity + Vacuum
stab.
Shinya Kanemura, Mariko Kikuchi and KY, arXiv: 1401.0515
71
One-loop corrected hZZ coupling
Even taking the maximal nondecoupling case (M2=0), the amount of correction is less than 1%.
1 - sin2(β - α)
Kanemura, Okada, Senaha, Yuan, PRD70 (2004).
Tanβ = 2,mΦ = 300 GeV
72
Higgs Physics = “Bridge” connecting the SM and New Physics. Indirect Search = Comparing fingerprints of the Higgs couplings.
Typical patterns of deviations in extended Higgs sectors at tree level 1. Higgs singlet model → κf and κV are universally suppressed.
2. Two Higgs doublet models → 4 patterns in κf’s.
3. Triplet models → κf are universally suppressed and κV can be larger than 1.
Radiative corrections to the Higgs boson couplings 1-loop corrections from extra Higgs bosons to the hhh, hff and hVV couplings
can be maximally O(100)%, O(5)% and O(1)%, respectively.
If 1% deviation in the hZZ couplings is found, we can discriminate
four types of 2HDM by precisely measured hff couplings.
Summary
73