Higgs as a Probe of New Physics Shinya KANEMURA Osaka University - - PowerPoint PPT Presentation
Higgs as a Probe of New Physics Shinya KANEMURA Osaka University Strings and Fields 2017 , at YITP, Kyoto Univ., 8 August 2017 This talk IntroducKon Probing the Higgs sector at future colliders Higgs potenKal and EW Phase TransiKon GravitaKonal
Strings and Fields 2017, at YITP, Kyoto Univ., 8 August 2017
IntroducKon Probing the Higgs sector at future colliders Higgs potenKal and EW Phase TransiKon GravitaKonal waves as a probe of Higgs sector Summary
Spontaneous Symmetry Breaking: Mass
SU(2)I × U(1)Y → U(1)em
Color Isospin Hypercharge
Bµ
Weak bosons Photon Gluon Massive Massless Quarks and leptons 3-generaKons
Gauge principle: InteracKon
Massive
Spontaneous Symmetry Breaking: Mass
SU(2)I × U(1)Y → U(1)em
TentaKvely introducing a scalar doublet (Higgs field)
Φ = φ+ φ0
√ 2 (v + h + iz)
Color Isospin Hypercharge
Bµ
Weak bosons Photon Gluon ↓VEV 246GeV
Higgs boson
Massive Massless Quarks and leptons 3-generaKons μ2 < 0
Gauge principle: InteracKon
Massive
Spin, Pality 0+ Coupling with many parKcles hγγ, hgg, hZZ, hWW, hττ, h), hbb, …
ATLAS/CMS July 2012
Discovery of a scalar parKcle IdenKfied as a Higgs boson Mass 125 GeV, … Measured couplings turned out to be consistent with the SM Higgs
SM predic<on
TentaKve SM Higgs sector works well! No BSM parKcle has been found
Standard Model is enough?
κτ = 0.90
+ 0.14 − 0.13
κb = 0.67
+ 0.22 − 0.20 ATLAS-CONF-2015-044 Assump<on, absense of BSM par<cles in the loops and BRBSM =0
κZ = 1.00
+ 0.10 − 0.11
κW = 0.91
+ 0.09 − 0.09
κt = 0.89
+ 0.15 − 0.13
Run 1 Best fit values for combinaKon
Roughly Higgs couplings are determined by 20 %
ATLAS Masbuchi-san’s Slide
The LHC Run II data show … No contradicKon with the SM predicKon No signal for new BSM phenomena The SM is enough?
The LHC Run II data show … No contradicKon with the SM predicKon No signal for new BSM phenomena The SM is enough? If the SM is correct up to very high scales, we may be able to get important informaKon at the Planck scale
arXiv:1205.6497, Degrassi et al
τEW >> τU
At Planck Scale, λ(Mpl) < 0, but the theory saKsfies the condiKon of the meta-stable vacuum
We are one the edge!
UnificaKon of Law
– Paradigm of Grand UnificaKon – Yukawa structure (flavor physics)
Problem in the SM Higgs
– Hierarchy Problem, Shape of Higgs sector, Nature, …
BSM Phenomena
– Dark Maoer – Neutrino mass and mixing – Baryon Asymmetry of Universe – InflaKon, Dark Energy, Gravity,…
New Physics is necessary At which scale?
12
There are many reasons to consider New Physics beyond SM If TeV scale, they should have connecKon with Higgs physics
Higgs boson was found, but Higgs sector is unknown
・ Nature of Higgs boson Hierarchy Problem New paradigm of New Physics By the discovery of h(125), these problems became fronKer ・ Structure MulKplet structure, Symmetry, … RelaKon to new paradigms and BSM phenomena ・ Higgs PotenKal EW Symmetry Breaking Dynamics of EWSB EW Phase TransiKon
μ2 < 0 Only one Higgs?
experiments
We can access to the new physics empirically via the Higgs physics!
– Elementary Scalar – Composite of fermions – A vector field in extra D – Pseudo NG Boson – ……
SUSY Dynamical Symmetry Breaking Minimal Composite Models Gauge Higgs UnificaKon
……
Each new paradigm predicts a specific Higgs sector (eg. MSSM: two Higgs doublets, Gauge-Higgs Uni.: Higgs couplings are weaker)
AlternaKve Scenario by quantum effects Physics of specific extended Higgs sectors Seesaw Mechanism Majorana mass
Seesaw Zee model
Tiny mass Large mass of Right-handed Neutrinos
←
Quantum suppression
Tiny mass
Quantum effect due to addiKonal scalar fields
Mediated by RH neuKrnos NR Mass around TeV scale
Neutrino OscillaKon → Tiny mass ( < eV)
16
Baryon Number
ηB = nB nγ = nb − nb nγ (= (5− 7)×10−10)
What is the mechanism to generate the baryon asymmetric Universe from the symmetric one? Baryogenesis
17
Baryon Number
Sakharov’s CondiKon
equilibrium SM could saKsfy these condiKons but excluded by the data
ηB = nB nγ = nb − nb nγ (= (5− 7)×10−10)
What is the mechanism to generate the baryon asymmetric Universe from the symmetric one?
Sakharov 1967
Sphaleron process Chiral gauge theory KM phase Strongly first order phase transiKon
Baryogenesis
18
Baryon Number
Sakharov’s CondiKon
equilibrium SM could saKsfy these condiKons but excluded by the data
ηB = nB nγ = nb − nb nγ (= (5− 7)×10−10)
What is the mechanism to generate the baryon asymmetric Universe from the symmetric one?
Sakharov 1967
Sphaleron process Chiral gauge theory KM phase Strongly first order phase transiKon
Scenario of Baryogenesis
Baryogenesis
19
Higgs portal new physics scenarios
SUSY Dynamical symmetry breaking Higgs as a pNGB Gauge Higgs UnificaKon CW mechanism Higgs portal dark maoer Inert scalar models RadiaKve neutrino mass models Electroweak baryogenesis …
It is important to experimentally determine the Higgs sector to explore new physics beyond SM
MulKplet Structure (with addiKonal scalars) ΦSM+Isospin Singlet, ΦSM+Doublet (2HDM), ΦSM+Triplet, … AddiKonal Symmetry Discrete or ConKnuous? Exact or Soyly broken? InteracKon Weakly coupled or Strongly Coupled? Decoupling or Non-decoupling?
MulKplet Structure (with addiKonal scalars) ΦSM+Isospin Singlet, ΦSM+Doublet (2HDM), ΦSM+Triplet, … AddiKonal Symmetry Discrete or ConKnuous? Exact or Soyly broken? InteracKon Weakly coupled or Strongly Coupled? Decoupling or Non-decoupling?
Baryogenesis CP ViolaKon 1st OPT Neutrino Mass Type III Seesaw RadiaKve Seesaw Dark Maoer (Inert scalar) EffecKve Theory of BSM (MSSM, NMSSM, ….) Models of Dynamical Symmetry Breaking
Sharing the VEV Field Mixing DeviaKon in the couplings of h(125) New ParKcles
CP-odd Charged AddiKonal bosons h(125)
Other three are unphysical Nambu-Goldstone bosons
↑
SM 2HDM hVV 1 → hVV sin(β−α)
h(125), H, A, H+, H++, …
EW parameters mW , S, T, U, Zff, Wff’, WWV, ...
Couplings of h(125) hWW, hZZ, hγγ, hff, hhh, …
Run1 7-8 TeV 20}-1 Run 2,3 13-14 TeV 300}-1 HL-LHC 14 TeV 3000}-1
h, H, A, …
p p At some probability, elementary process with very large energy can occur
Machine for discovery Precision rather limited by huge QCD backgrounds
Machine for precision measurements!
e+ e−
Simple KinemaKcs Low QCD backgrounds Beam polarizaKon (linear collider) Energy Scan (linear collider)
Machine for precision measurements!
e+ e−
Simple KinemaKcs Low QCD backgrounds Beam polarizaKon (linear collider) Energy Scan (linear collider)
InternaKonal Linear Collider (ILC)
Next GeneraKo Linear Collider Energy 250GeV (500 GeV, 1TeV) TDR published Technically ready WaiKng for approval Hosted by Japan (Iwate)
Current Future Measurement accuracy at ILC (500-up) hVV coupling by about 0.4% (95% CL) Yukawa coupling by a few % (95% CL)
Snowmass Higgs Working Group Report 2013
2 =sin2(β−α)
Excluded by Unitarity bounds
Scaling factor κi : factor of deviaKon from the SM value
Coupling of h(125) and weak bosons V (=W, Z) hVV
κV
2
mH (GeV)
SM value DeviaKon
Leff = LSM + v2 M 2O(6)
If a 2% deviaKon in κV
2
2 =sin2(β−α) The second Higgs H must be lighter than 800 GeV
Excluded by Unitarity bounds
Scaling factor κi : factor of deviaKon from the SM value
Precision test has the similar power to the direct search Coupling of h(125) and weak bosons V (=W, Z) hVV
κV
2
mH (GeV)
SM value DeviaKon
Leff = LSM + v2 M 2O(6)
Indirectly, new physics can be surbeyed by detecKng deviaKons even out of the direct search regions
SK, Tsumura, Yagyu, Yokoya, 2014
Region
at LHC300
mH (GeV) tanβ Direct detecKon of the heavier Higgs boson H at LHC Type-II 2HDM H H
H → τ τ HL-LHC κV
2=0.98
Indirect limits allowed by tree unitarity when
We can fingerprint extended Higgs models from the paoern of deviaKon in Higgs couplings Type-I Type-II Type-X Type-Y
hττ hbb hcc hVV
κV κτ κb κc
cos(β-α) < 0
Gauge couplings Yukawa couplings
DirecKon of deviaKon in each coupling
SK, K. Tsumura, K. Yagyu, H. Yokoya, 2014
Ellipse = 68.27% CL
hbb vs hττ
SK, K. Tsumura, K. Yagyu, H. Yokoya, 2014
If deviaKon in κ2
V can be
large enough to be detected at future collider
κτ κb
SM point
4-models can be separated by looking at deviaKons in Yukawa couplings κτ, κb, κc,
…
When a Fermion couples to Φ1 κf = 1 + cotβ x + … and if it couples to Φ2 κf = 1 − tanβ x + …
κV = 1 - (1/2) x2 + …
SM-like: |x| <<1
x = cos(β−α)
FingerprinKng models by precision study at ILC
36
Higgs couplings hγγ, hgg, hWW, hZZ, hττ, hbb, h), … will be measured thoroughly in the future Future Precision Measurements Accurate Theory Predictions
New Physics!
Full set of Fortran codes to systemaKcally calculate quantum correcKons to Higgs couplings in various extended Higgs models
H-COUP ver. 1 is released in 2017
Clearly analyses with radiaKve correcKon is necessary
H-COUP Project
AddiKonal Singlet 2HDM (I) 2HDM (II) 2HDM (X) 2HDM (Y) Inert doublet/singlet Triplet model SK, Kikuchi, Yagyu (2012−2016)
Models
We can fingerprint these models, if a deviaKon in κZ is detected
IDM IDM Scan of inner parameters (mass, mixing angles) under ・ PerturbaKve unitarity ・ Vacuum stability, ・ Avoiding wrong vacua
Ellipse, ±1σ at LHC3000 and ILC500
SK, M. Kikuchi, K. Yagyu, 2015
Example of H-COUP
PredicKon on hbb, hττ, hγγ
Most important part for the EW symmetry breaking (Yet to be tested by experiment)
– Where come from μ2 < 0 – What is the origin of λ – Dynamics
– Aspect of TransiKon, 1st order or not? – RelaKon to EW baryogenesis – Mechanism of Phase TransiKon
T
T T
c
T
c
Veff, T
PotenKal Barrier True Vacuum False Vacuum Quantum Tunneling
ϕc/Tc ∝ E
EffecKve potenKal at one-loop Finite temperature parts High temperature expansion
Bosonic loop contribute to the cubic term → 1st OPT stronger
Sphaleron Decoupling (Strong 1st OPT)
T
c
T Tc T Tc
Veff, T
Expanding Bubble
Physics of the Higgs potenKal
Sakharov 3rd condiKon
Departure from Thermal equilibrium
f f Symmetric Phase Broken Phase Sphaleron transiKon
ΔB ≠ 0
Shpaleron TransiKon decouples
nB is frozen
Thermal non- equiliburium
around the wall
PotenKal at finite T (high temp. approx.) SM
Quantum non-decoupling effect
no strong 1st OPT Extended Higgs (2HDM): 1st OPT possible PredicKon! Large deviaKon in the hhh couping as well
> λhhh
SM
E: Thermal Loop Effects λTc : Self couplings ~ mh
2
S.K., Y. Okada, E. Senaha (2005)
Strong 1st OPT ⇔ DeviaKon in the hhh coupling
φC/TC>1
DeviaOon in hhh
2HDM
Only ILC (1 TeV) can measure it by O(10) %
K.Fujii et al., arXiv:1506.05992 [hep-ex]
EW Baryogenesis can be tested by detecKng a large deviaKon in the hhh coupling
ConnecKon between Cosmological problem and Collider
Which collider? LHC cannot do it
Slide by Keisuke Fujii
Originally, ILC was planned with /s=500 GeV with extension to /s=1000 GeV, where the hhh coupling can be measured with 10%. However, because of financial reason, the energy of ILC will be limited as 250GeV with running longer Kme This ILC(250) can work well as a Higgs factory. But the top Yukawa and the hhh coupling cannot be measured In the future, we cannot access the Higgs potenKal for long Kme!!!
ILC Original (planned)
ILC1TeV?
LHC Run2, 3
HL-LHC
Super KEKB
2015 2020 2025 2030 2035 2040 2050
TODAY
2045
ILC250 with 1-2 ab-1 (planned)
ILC1TeV? Measurement
LHC Run2, 3
HL-LHC
Super KEKB
2015 2020 2025 2030 2035 2040 2050
Far future!
Precision measurement
TODAY
2045 ?
Direct detecKon of GravitaKonal Waves at LIGO in 2016 Space based GW interferometer LISA has been approved recently, which will start in 2034 We may be able to access the Higgs potenKal
from 1st Order Phase transiKon
ILC250 with 1-2 ab-1 (planned)
ILC1TeV? Measurement
LHC Run2, 3
HL-LHC
Super KEKB
2015 2020 2025 2030 2035 2040 2050
Far future!
Precision measurement
TODAY
2045 ?
EW Phase TransiKon via GWs
LISA (approved!) 2034--
ILC250 with 1-2 ab-1 (planned)
ILC1TeV? Measurement
LHC Run2, 3
HL-LHC
Super KEKB
2015 2020 2025 2030 2035 2040 2050
TVeff, T
Far future!
Precision measurement
TODAY
2045 ?
EW Phase TransiKon via GWs
LISA (approved!) 2034--
SuperKEKB Flavor Physics HL-LHC Energy FronKer (New ParKcle Searches) ILC Precision measurement of Higgs couplings LISA EW Phase TransiKon from GWs
Synergy! ILC250 with 1-2 ab-1 (planned)
ILC1TeV? Measurement
LHC Run2, 3
HL-LHC
Super KEKB
52
2015 2020 2025 2030 2035 2040 2050
TVeff, T
Far future!
Precision measurement
TODAY
2045 ?
In 2016, aLIGO reported the first direct observaKon of GWs from merge of a BH Binary (〜100 Hz) → Era of GW astronomy started Ground based experimetns aLIGO, KAGRA, aVirgo…
In 2016, aLIGO reported the first direct observaKon of GWs from merge of a BH Binary (〜100 Hz) → Era of GW astronomy started Ground based experimetns aLIGO, KAGRA, aVirgo…
GW Physics?
GW from 1st OPT: homogeneous, isotropic, staKonary, unpolarized T = 100GeV → f = 10−1 −10−3 Hz Out of sensiKvity at LIGO/KAGRA (10-103Hz) Relic GWs are characterized only by frequency TransiKon temperature gives typical frequencies
Relic GWs from 1st OPT are staKsKcally
– Homogeneous （一様） – Isotropic （等方） – StaKonary （静的） – Unpolarized （無偏極）
The GWs are only characterized by their spectra Typical frequency f Typical strength ΩGW(f)
RadiaKon dominant Universe
Red-shiyed frequency
ConservaKon of the entropy per comoving volume We obtain ft /Ht must be > 1, typically 102 (102-104)
f0 = 10-3-10-1 Hz
at: scale factor ft : frequency at the transiKon
1/ft Wavelength of GWs at the PT 1 /Ht Size of the universe (horizon) at the PT
In 2016, aLIGO reported the first direct observaKon of GWs from merge of a BH Binary (〜100 Hz) → Era of GW astronomy started Ground based experimetns aLIGO, KAGRA, aVirgo…
GW Physics?
GW from 1st OPT: homogeneous, isotropic, staKonary, unpolarized T = 100GeV → f = 10−1 −10−3 Hz Out of sensiKvity at LIGO/KAGRA (10-103Hz) Relic GWs are characterized only by frequency TransiKon temperature gives typical frequencies
In 2016, aLIGO reported the first direct observaKon of GWs from merge of a BH Binary (〜100 Hz) → Era of GW astronomy started Ground based experimetns aLIGO, KAGRA, aVirgo…
GW Physics?
GW from 1st OPT: homogeneous, isotropic, staKonary, unpolarized T = 100GeV → f = 10−1 −10−3 Hz Out of sensiKvity at LIGO/KAGRA (10-103Hz)
LISA（USA/Europe） DECIGO（Japan）
SensiKvity around mili Hz SensiKvity around deci Hz
Future space based GW experiments We can explore GWs from the early Universe!
(2034−)
Relic GWs are characterized only by frequency TransiKon temperature gives typical frequencies
川村静児氏のスライド
ProperKes of the representaKve LISA configuraKons
61
C.Caprini et al., arXiv:1512.06239
FP (Fabry-Perot)-DECIGO
1 cluster (arm length 1000km) CorrelaKon between 2 cluster
LISA has been approved in 2016 It will start from 2034 Laser interferometer space aniena
Broken Phase r0: size of cri<cal bubble
Bubble is spherical → No GW occurs
Expanding babbles of the broken phase
Bubble nucleaKon in the universe
Symmetric Phase
“Sound waves” (Compressional plasma) “Wall Collisions” (Envelope approximation)
Spherical symmetry is violated by bubble collisions → ︎ GW occurs
“Turbulences in the plasma”
Source of GW
Bubble Collisions
Red shiyed abundance Normalized energy density
Scaling
Transverse-Traceless gauge
Einstein EquaKon At the phase transiKon, we have Typical duraKon of the phase transiKon: 1/β Eenergy density at PT
The spectrum is determined by α (latent heat), β (duraKon of PT), κ (Efficiency) They can be basically calculated if a model is given.
This rough esKmaKon is applicable to GWs from the wall collision. However, Ωh2 is enhanced by β/Ht for GWs from the moKon
Energy density of false vacuum released by PT Efficiency of kineKc energy of walls in the release energy.
Abundance of GWs
The spectrum are evaluated by inpuŠng the latent heat α, variaKon
C.Caprini et al., arXiv:1512.06239
Complicated numerical simulaKons are necessary
Approximate fiŠng formulae given by : wall velocity
vb
✏ = 0.05
κφ κv : efficiency factors
α Latent heat (released energy of false vacuum) β Inverse of duraKon of phase transiKon
Ex) Strength and peak frequency of GW (FiŠng funcKon)
C.Caprini et al., arXiv:1512.06239
Γ(T) = Γ0 exp(− S3 /T) Tt TransiKon temperature GW spectrum is given as a funcKon of Tt, α, β (and vb)
Veff(φ, Tt) φ
tunneling
false true Depth of the potenKal
Speed of transiKon
68
Bubble nucleaKon rate per unit volume and Kme
vb: wall velocity
Imposed O(N) for simplicity Mass of scalar fields:
φc/Tc > 1 is saKsfied by the nondecoupling effect of the singlet fields （compaKble with mh=125GeV）
> λhhh
SM
Large deviaKons in hhh coupling
E x c l u d e d b y u n i t a r i t y b
n d
N 12
c Tc 1.0
ΛhhhON ΛhhhSM 500 2
20 5 100
Excluded by vacuum stability bound
H
4 T
t 1
50 100 150 200 250 300 100 200 300 400 500 600 ΜS2 GeV mSGeV
SensiKviKes eLISA
arXiv:1512.06239
DECIGO
28, 094011 (2011)
N = 1
4 60
N scalar model
Mass ms is chosen such that the peak strength is maximal
Bound from Non-observa<on of energy density of extra radia<on
For larger ms Γ/H4 = 1 cannot be saKsfied
For smaller ms φc/Tc>1 cannot be saKsfied SensiKviKes eLISA arXiv:1512.06239
DECIGO,
28, 094011 (2011)
N ms O(N) singlet model with the mass mS
72
SensiKviKes eLISA arXiv:1512.06239
DECIGO,
28, 094011 (2011)
N ms O(N) singlet model with the mass mS
73
If α and β are determined with a resoluKon, We may be able to fingerprint the model with (N, mS)
EW Phase TransiKon via GWs
LISA (approved!) 2034--
SuperKEKB Flavor Physics HL-LHC Energy FronKer (New ParKcle Searches) ILC Precision measurement of Higgs couplings LISA EW Phase TransiKon from GWs
Synergy! ILC250 with 1-2 ab-1 (planned)
ILC1TeV? Measurement
LHC Run2, 3
HL-LHC
Super KEKB
74
2015 2020 2025 2030 2035 2040 2050
TVeff, T
Far future!
Precision measurement
TODAY
2045 ?
Higgs singlet model
Non-thermal effect ↑
→ (h, H) with
EW II SYM I B A D C
MulK-field analysis of EWPT is necessary Public tool “CosmoTransiKon” (Python code) is used.
Thermal loop effect ↓
LISA and DECIGO are capable of detecKng GWs from 1st OPT in the HSM.
21
K.Hashino, M.Kakizaki, S.K., T.Matsui, P.Ko, arXiv1608.00297 Benchmark point LISA (C1-C4): DECIGO (Pre, 1 cluster, Correla<on) [Caprini et al. (2015)] [Kawamura et al. (2011)]
Direct searches of the second Higgs at LHC Self-coupling hhh measurement at ILC
κ =κV=κf =cosθ
Precision measurement at ILC/LHC
Region of Strong 1st OPT
Direct searches of the second Higgs at LHC Self-coupling hhh measurement at ILC Measurement of GravitaKonal Waves at LISA/DECIGO Precision measurement at ILC
κV : 2%
∆λhhh : 10%
κZ : 0.37% κW : 0.51%
κ =κV=κf =cosθ
HL-LHC ILC
◉ Structure of the Higgs sector is directly connected to each
scenario of new physics
◉ Extended Higgs sectors can be tested directly by discovering the
2nd Higgs bosons, or indirectly by measuring the couplings of h(125). ◉ DetecKng a paoern of deviaKons in the h(125) couplings, we can fingerprint the Higgs sector and further direcKon of new physics
property is tested by measuring the hhh coupling at colliders
deviaKons in the hhh coupling and also produce GravitaKonal Waves
fingerprint models of 1st OPT
among direct searches at HL-LHC, precision measurements of Higgs couplings (κi) at ILC and the GW spectrum at LISA in 2030s
Baryogenesis Dark Maoer Cosmic InflaKon
Hierarchy
Neutrino mass
LHC New parKcle searches SKEKB Flavor physics ILC Precision study LISA GravitaKonal Waves
これからますます 面白くなる Physics at Planck scale
Synergy and Complementarity
81
83
Decay Rate of EW vacuum (Tunneling effect)
Decay Probability If λ(ht) = − 0.01, τU << τEW . If λ(ht) < − 0.05, τU > τEW .
Instability and dangerous
Meta-stable but not dangerous
EW vacuum tunneling λ < 0
DesKny of the Universe is determined by the balance
84
Snowmass White Paper (Aug. 2013) g(hxx)=κx g(hxx)SM
ILC Higgs White Paper Asner, Barklow, Fujii, Haber, Kanemura, Miyamoto,Weiglein, et al.
Snowmass Higgs Working Group Report 1310.8361
87
[Espinosa et al. (2010)]
川村静児氏のスライド
川村静児氏のスライド