[PPT] - 2018-08-19 The Great Standard PowerPoint Presentation, free download

SLIDE 1

2018-08-19

SLIDE 2

Matter"particles" Force"particles"

The Great Standard Model

2

(1895 - 2012)

SLIDE 3

Two outstanding puzzles in SM

3

(GeV) Proton mass

Weak scale

1019 103 102 101 1015 100 10-3 10-9 P L A N C K G U T TeV NP

t

e

344000

1GeV = 109eV

W/Z Masses Fermion Mass)

Origins of EWSB and Flavor breaking

SLIDE 4

Electroweak Triangle

4

H

t

Symmetry breaking Flavor breaking

W/Z gW gY

L = (DµΦ)† (DµΦ) − µ2Φ†Φ + λ

Φ†Φ

2

+yf ¯ FLΦfr + · · ·

Yf gW gY

m2

h = mt × mZ

λ, µ

SLIDE 5

Electroweak Triangle

4

H

t

Symmetry breaking Flavor breaking

W/Z gW gY

L = (DµΦ)† (DµΦ) − µ2Φ†Φ + λ

Φ†Φ

2

+yf ¯ FLΦfr + · · ·

Yf gW gY

m2

h = mt × mZ

λ, µ

Goldstone Equivalence Theorem Spontaneous Electroweak Symmetry Breaking Massive W-Boson Study interaction of in the TeV region Existence of longitudinal W-boson WL

WLWL → WLWL

WL can also interact strongly with top quark as

d

u

L

W

b t

g u

d

T

W

b t

g u u t t g

mt = v √ 2 = 174 GeV

gweak ∼ 1 2.5 gs ∼ 1 geff ∼ 1

SLIDE 6

Electroweak Triangle

4

H

t

Symmetry breaking Flavor breaking

W/Z gW gY

L = (DµΦ)† (DµΦ) − µ2Φ†Φ + λ

Φ†Φ

2

+yf ¯ FLΦfr + · · ·

Yf gW gY

m2

h = mt × mZ

λ, µ

Equivalence Theorem

t b φ+ t b

W +

gW gY

SLIDE 7

What can Higgs Boson tell us?

5 Relation between MW and MZ (custodial Symmetry)

The Higgs boson is important not only for EWSB, but also as a WINDOW to NP beyond the SM.

Relation between HVV and HHVV couplings

HVV coupling HFF coupling

Higgs-self couplings HHH and HHHH

Magnitude and CP

SLIDE 8

1) Higgs-self Interaction

6

(probing potential at electroweak scale)

Coleman-Weinberg Higgs

V () = (†)2 + ✏(†)2 log † µ2

Pseudo-Goldstone Higgs

V (φ) = a sin2(φ/f) + b sin4(φ/f)

V(ϕ) = − μ2ϕ2 + λ(μ)ϕ4 + κ(μ) Λ2 ϕ6 + ⋯

SLIDE 9

1) Higgs-self Interaction

7

Higgs pair production

g g H H t t t t g g H H H t t t

(probing potential at electroweak scale)

V(ϕ) = − μ2ϕ2 + λ(μ)ϕ4 + κ(μ) Λ2 ϕ6 + ⋯

SLIDE 10

2) HVV versus HHVV

8

SM predicts a definite ratio between HVV and HVV couplings

2

2

V

M i g v

2

2

V

M i g v

If the ratio is modified by NP, the unitarity of VV->HH is broken

(tree-level relation)

SLIDE 11

Higgs Boson Pair Production

9

SLIDE 12

Sensitivity to HHH coupling gg->HH: the leading channel

10

J. Baglio, A. Djouadi et al. JHEP 1304(2013)51

SLIDE 13

Sensitivity to HHH coupling gg->HH: the leading channel

11

Low-energy theorem (Dawson and Haber, 1989)

Strong cancelation

SLIDE 14

Sensitivity to HHH coupling gg->HH: the leading channel

12

J. Baglio, A. Djouadi et al. JHEP 1304(2013)51

Low Energy Theorem

Strong cancelation

SLIDE 15

M (GeV)

300 400 500 600 700 800 900 1000

)

1

/dM (TeV σ d σ 1/

1 2 3 4 5

NNLL+NLO = -1

SM

λ / λ = 0

SM

λ / λ = 1

SM

λ / λ = 2

SM

λ / λ

13

HH production

g g H H t t t t g g H H H t t t

Unfortunately, it is not a easy job at the LHC or even at the SppC.

gg->HH: the leading channel

D.-Y. Shao, C.-S. Li, H.-T. Li, and J. Wang, JHEP 07 (2013) 169

Not accessible at detector!

SLIDE 16

Too many things involved in

14

µhh = A1c2

3hc2 g + A2c2 3hcgct + A3c2 3hc2 t + A4c3hcgc2g + A5c3hcgc2 t + A6c3hc2gct + A7c3hcg˜

c2

t

+ A8c3hc3

t + A9c3hct˜

c2

t + A10c2 2g + A11c2gc2 t + A12cg˜

c2

t + A13c4 t + A14c2 t ˜

c2

t + A15˜

c4

t

+ A16c2

3h˜

c2

g + A17c2 3h˜

cg˜ ct + A18c2

3h˜

c2

t + A19c3h˜

cg˜ c2g + A20c3h˜ cgct˜ ct + A21c3h˜ c2g˜ ct + A22˜ c2

2g + A23˜

c2gct˜ ct + A24c2

2t + A25c2tc3hcg + A26c2tc3hct + A27c2tc2g + A28c2tc2 t

+ A29c2t˜ c2

t + A30ct˜

ct˜ c2t + A31c3h˜ ct˜ c2t + A32c3h˜ cg˜ c2t + A33˜ c2

2t + A34˜

cg˜ c2t.

✿✿✿✿✿✿

√s A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 14 TeV 0.138 0.370 0.276 0.640

0.766

0.821 0.535

1.35
6.22

1.37

1.82

1.58 100 TeV 0.101 0.267 0.208 0.592

0.569

0.658 0.425

1.11
4.79

3.32

1.30

1.67 √s A13 A14 A15 A16 A17 A18 A19 A20 A21 A22 A23 A24 14 TeV 2.07 13.9 0.719 0.138

0.611

0.861 0.640 2.13

1.24

1.37 4.64 2.55 100 TeV 1.90 11.3 0.680 0.101

0.428

0.634 0.592 1.53

0.928

3.32 3.51 2.90 √s A25 A26 A27 A28 A29 A30 A31 A32 A33 A34 14 TeV 0.821 1.39 2.44

4.24

2.30

18.8

4.04

1.24

6.19

3.02

100 TeV 0.658 1.21 2.06

4.13

2.16

16.3

3.28

0.928

6.10

2.08

Leff = −mt v ¯ t(ct + i˜ ctγ5)th − mt 2v2 ¯ t(c2t + i˜ c2tγ5)th2 + αsh 12πv(cgGA

µνGA,µν + ˜

cgGA

µν ˜

GA,µν) + αsh2 24πv2 (c2gGA

µνGA,µν + ˜

c2gGA

µν ˜

GA,µν) − c3h m2

h

2v h3, QHC, Li, Yan, Zhang, Zhang, Phys.Rev. D96 (2017) no.9, 095031

gg → HH → b¯ bγγ

SLIDE 17

Sensitivity to HHH coupling: 2) VBF and VHH

15

J. Baglio, A. Djouadi et al. JHEP 1304(2013)51

VBF and VHH are sensitive to HHH coupling differently

SLIDE 18

Sensitive to Triple Higgs Coupling Differently

16

Near the threshold of Higgs-boson pairs

VBF: VHH:

Mμν = m2

W

v2 6m2

H

̂ s − m2

H

λHHH λSM

HHH

+ 2m2

W

v2 + 4m4

W

v2 ( 1 ̂ t − m2

W

+ 1 ̂ u − m2

W)

gμν + ⋯

̂ t = ̂ u = Q2 < 0 ̂ t = ̂ u = Q2 > 0

Mμν ∼ 2m2

V

v2 ( λHHH λSM

HHH

− 3) gμν + ⋯ Mμν ∼ 2m2

V

v2 ( λHHH λSM

HHH

+ 1) gμν + ⋯

SLIDE 19

Sensitivity to HHH Coupling

17

VBF VHH

Mμν ∼ 2m2

V

v2 ( λHHH λSM

HHH

− 3) gμν + ⋯ Mμν ∼ 2m2

V

v2 ( λHHH λSM

HHH

+ 1) gμν + ⋯

SLIDE 20

HH and VHH @14 TeV LHC

18 Cross section: 34 fb

vs

Cross section: 0.57 fb

>>

Huge backgrounds: Main backgrounds:

× Br(bbbb`⌫) = 0.042 fb

SLIDE 21

VBF and WHH @14 TeV LHC

Cross section: 2.01 fb

vs

Cross section: 0.57 fb >>

Huge backgrounds

>

Isolated weak boson fusion?

M. J. Dolan et al, Eur.Phys.J.C75(2015)8,387

19

× Br(bbbb`⌫) = 0.042 fb

SLIDE 22

WHH and ZHH Productions

20

The discovery potential of triple Higgs coupling in VHH production is comparable to other channels.

QHC, Liu, Yan, Phys.Rev. D95 (2017) no.7, 073006

0.5 ≤ κ ≤ 2.2

Nordstrom and Papaefstathiou (arXiv:1807.01571) include full detector effects and show that measuring HHH coupling via WHH and VHH channels is very challenging.

SLIDE 23

Higgs as a pseudo Nambu-Goldstone

21

The Signature of Pseudo Nambu-Goldstone Higgs Boson in its Decay

Ling-Xiao Xu School of Physics, Peking University

Collaborate with Qing-Hong Cao, Bin Yan, Shou-hua Zhu, to appear

Aug ??, 2018 @ Tianjin

1

SLIDE 24

Huaqiao Zhang (IHEP)

1

Observation of ttH at CMS

2018619-24

Lianliang MA

Shandong University

June 20-24, 2018@Shanghai

First observation of Higgs-Top coupling

µt¯

tH = 1.26+0.31 −0.26

CMS: PRL120,231801 (2018)

3) Higgs-Fermion Interaction

SLIDE 25

Good News: Higgs-Bottom Coupling

23

July 9th, ICHEP18, Seoul

SLIDE 26

Sizing Up Top Quark’s Interaction with Higgs

24 QHC, Chen, Liu PRD95 (2017) 053004

|

SM t

y /

t

y | 0.5 1 1.5 2 2.5 ) (fb) t t t (t σ

10 20 30 40 50 60

Obs. upper limit
Obs. cross section
Phys. Rev. D 95 (2017) 053004

Predicted cross section,

(13 TeV)

1

35.9 fb

CMS

arXiv:1710.10614

yt/ySM

t

≤ 2.1

ff-shell

g g t t ¯ t ¯ t H

ff-shell

t ¯ t h g g

n-shell
tth associated production

No assumption

n Higgs decay

Four-top production

CMS

SLIDE 27

The CP property of Htt coupling

25

Goncalves,Kim, Kong arXiv:1804.05874

0.0 0.5 1.0 1.5 0.00 0.05 0.10 0.15

angle Normalized Distribution

QHC, Xie, Zhang in preparation

0.0 0.5 1.0 1.5 0.00 0.02 0.04 0.06 0.08 0.10

angle Normalized Distribution

After cuts no need to reconstruct top quark Hadron level After cuts Hadron level

t ¯ t h g g

γ γ h t ¯ t g g

CS-frame

need top-quark reconstruction

SLIDE 28

Interim Summary

26

H

t

Symmetry breaking Flavor breaking

W/Z

Equivalence Theorem

Yf gW gY λ, µ

More accurate knowledge of Higgs boson might shed lights on NP.

d

u

L

W

b t

g

geff ∼ 1

+yf ¯ FLΦFR + ⋯

ℒ = (DμΦ)

†

(DμΦ) − μ2Φ†Φ + λ (Φ†Φ)

2

SLIDE 29

What if NP knew nothing about Higgs?

27

Higgs boson discovery the END of the era of SM

Q2. Heavy NP particles cannot achieve mass mainly from Higgs.

NP scale = New Resonance Mass ~ 2TeV

1019 103 102 101 1015 100 10-3 10-9

P L A N C K G U T

TeV

See- Saw

GeV

Q1. Why are light quarks so light?

Top quark and W/Z bosons are naturally around the weak scale.

SLIDE 30

The EFT of QED (infinite me )

28

Heisenberg-Euler operator in QED

136 a Lectures on QED and QeD

"'_ ....

/." -,,'

I "

'\

, "'_

.... ,

1-

\ \ .. _

....

1

\ "

.... -

'" ,,' 1

, ....

,

/

....

'"

b

Fig. 7.1

Scattering of low-energy photons

Photodynamics, with the Lagrangian L -

IF FJ.LV

-4"

J.LV

(7.1)

But later, after they increased the luminosity (and energy) of their "photon colliders" and the sensitivity of their detectors, they discover that photons do scatter, though with a very small cross-section (Fig. 7.1b). They need to add some interaction terms to this Lagrangian. Lowest-dimensional operators having all the necessary symmetries contain four factors FJ.Lv. There are two such terms: They can extract the two parameters Cl,2 from two experimental results, and predict results of infinitely many measurements. So, this effective field theory has predictive power. We know the underlying more fundamental theory for this effective low- energy theory, namely QED, and so we can help theoreticians from Pho-

tonia. The amplitude of photon-photon scattering in QED at low energies

must be reproduced by the effective Lagrangian (7.2). At one loop, it is given by the diagram in Fig. 7.2. Expanding it in the photon momenta, we can easily reduce it to the massive vacuum integrals (1.2). Due to the gauge invariance, the leading term is linear in each of the four photon mo-

menta. Then we equate this full-theory amplitude with the effective-theory
ne following from (7.2), and find the coefficients Cl,2 (this procedure is

(Imagine we are living in a world full of photon but not electron)

Conclusion: Effective field theories 137

Fig. 7.2 Photon-photon scattering in QED at one loop

known as matching). The result is

L = -

FJ.LIIFJ.LII +

[-5 (FJ.LIIFJ.LII)2 +

14FJ.LIIFIIQ FQ,BF,BJ.L]

(7.3)

It is not (very) difficult to calculate two-loop corrections to this QED am-

plitude using the results of Sect. 5.6, and thus to obtain 0:3 terms in these coefficients. There are many applications of the Lagrangian (7.3). For example, the energy density of the photon gas at temperature T is f'V T4 by dimensional- ity (Stefan-Boltzmann law). What is the radiative correction to this law? Calculating the vacuum diagram in Fig. 7.3 at temperature T, one can obtain [Kong and Ravndal (1998)] a correction f'V 0:2T8/m4. Of course, this result is only valid at T « m.

Fig. 7.3

Radiative correction to the Stefan-Boltzmann law

The interaction terms in the Lagrangian (7.3) contain the "new physics" energy scale, namely the electron mass m, in the denominator. If

we want to reproduce more terms in the expansion of QED amplitudes in the ratio w

/m

(w is the characteristic energy), we can include operators of higher dimen-

sions in the effective Lagrangian; their coefficients contain higher powers of m in the denominator. Such operators contain more FJ.LII and/or its deriva-

tives. Heisenberg and Euler derived the effective Lagrangian for constant

field containing all powers of FJ.LII; it is not sufficient for finding coefficients

f operators with derivatives of FJ.LII' The expansion in w/m breaks down

when w f'V m. At such energies the effective low-energy becomes useless, and a more fundamental theory, QED, should be used; in particular, real

After matching in QED

NP scale me

Conclusion: Effective field theories 137

Fig. 7.2 Photon-photon scattering in QED at one loop

known as matching). The result is

L = -

FJ.LIIFJ.LII +

[-5 (FJ.LIIFJ.LII)2 +

14FJ.LIIFIIQ FQ,BF,BJ.L]

(7.3)

It is not (very) difficult to calculate two-loop corrections to this QED am-

plitude using the results of Sect. 5.6, and thus to obtain 0:3 terms in these coefficients. There are many applications of the Lagrangian (7.3). For example, the energy density of the photon gas at temperature T is f'V T4 by dimensional- ity (Stefan-Boltzmann law). What is the radiative correction to this law? Calculating the vacuum diagram in Fig. 7.3 at temperature T, one can obtain [Kong and Ravndal (1998)] a correction f'V 0:2T8/m4. Of course, this result is only valid at T « m.

Fig. 7.3

Radiative correction to the Stefan-Boltzmann law

The interaction terms in the Lagrangian (7.3) contain the "new physics" energy scale, namely the electron mass m, in the denominator. If

we want to reproduce more terms in the expansion of QED amplitudes in the ratio w

/m

(w is the characteristic energy), we can include operators of higher dimen-

sions in the effective Lagrangian; their coefficients contain higher powers of m in the denominator. Such operators contain more FJ.LII and/or its deriva-

tives. Heisenberg and Euler derived the effective Lagrangian for constant

field containing all powers of FJ.LII; it is not sufficient for finding coefficients

f operators with derivatives of FJ.LII' The expansion in w/m breaks down

when w f'V m. At such energies the effective low-energy becomes useless,

and a more fundamental theory, QED, should be used; in particular, real

Application ( )

Radiative correction to the Stefan-Boltzmann law

ρ ∝ T 4, α2 m4 T 8

ω ⌧ m

SLIDE 31

EFT of QED (photon + electron)

29

NP scale Two ways to probe NP:

1. To raise collider energies to produce real new particles (muon); 2. To measure low-energy quantities (e.g. electron magnetic moment) with high precision We were lucky 90 years ago when the cosmic rays brought Muon lepton to us. What about now? L = ¯ ψ(i 6D m)ψ 1 4FµνF µν + c M 2 m ¯ ψFµνσµνψ + · · · mµ

Who

rdered

that?

SLIDE 32

LHC: A Precision Machine

30

S M NP operator

examine long-tail regions (high energy) Measure effective couplings accurately

Relations

f Wilson

Coefficients

in case of no new resonances were found in 10 years

SLIDE 33

1970 - 2018

31

500 1000 1500 2000 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004 2007 2010 2013 2016

Neutrino Higgs SUSY Top ExD DM

from inspires-hep

SLIDE 34

1970 - 2018

31

500 1000 1500 2000 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004 2007 2010 2013 2016

Neutrino Higgs SUSY Top ExD DM

Thank You!

from inspires-hep