Higgs Phenomenology in a Simple Model with Vector Resonances...

Higgs Phenomenology in a Simple Model with VectorResonances

Alfonso R. Zerwekh

Universidad Técnica Federico Santa María

Valparaíso, Chile

Mass 2013, Odense

Alfonso R. Zerwekh (UTFSM) Higgs and Vector Resonances Mass 2013, Odense 1 / 22

LHC at Odense

For sure, people at Odense need more LHC data !


Contents

1 Simple ModelBasic IdeaReview of the ModelLimits based on dijet spectrumh→ γγHiggs-strahlung

2 A Not So Simple Model

3 Comments and Conclusions

4 Further Thought a Little Bit Out of Subject (If time allows)


Simple Model Basic Idea

Original Motivation

In 2005 I read about the fantastic idea of a light composite Higgs inWTC:

D. D. Dietrich, F. Sannino and K. Tuominen, �Light composite Higgsfrom higher representations versus electroweak precisionmeasurements: Predictions for LHC,� Phys. Rev. D 72, 055001 (2005)[arXiv:hep-ph/0505059].

A question arose: Is there a clear collider signal ?

Idea: Associate Higgs and Gauge boson production should beenhanced because of the presence of vector resonances


Simple Model Basic Idea

Basic Idea

Suppose that:

A new strong sector is responsible for EWSB

The new strong sector produces

A light scalar (Higgs)Vector resonances (Techni-rho and Techni-omega)

Can we construct a simple model which can help us to understand thebasic phenomenology ?

Warning

The spectrum considered here is not the low energy spectrum suggested byMWT !


Simple Model Review of the Model

Basic Lagrangian

Gauge Sector: old VMD idea

L = −1

2Tr {WµνW

µν} − 1

2Tr {ρµν ρµν} −

1

4BµνB

µν − 1

4ωµν ω

µν

+M2Tr

{(g

g2Wµ − ρµ

)2}

+M2

2

(g ′

g2Bµ − ωµ

)2



Basic Lagrangian

Fermion Sector

L = ψLiγµDµψL + ψR iγ

µDµψR ,

with

Dµ = ∂µ + iτ ag(1− x1)W aµ + iτ ag2x1ρ

aµ

+iY

2g ′(1− x2)Bµ + i

Y

2g ′2x2ωµ

and

Dµ = ∂µ + iY

2g ′(1− x3)Bµ + i

Y

2g ′2x3ωµ.

xi = 2(g/g2)2 for i = 1, 2, 3 in order to be consistent with precisionmeasurements (see BESS model)



Basic Lagrangian

(A very standard) Higgs Sector

L = (DµΦ)† (DµΦ) + µ2Φ†Φ− λ(

Φ†Φ)2

Dµ = ∂µ + iτ ag(1− f1)W aµ + iτ ag2f1ρ

aµ

+iY

2g ′(1− f2)Bµ + i

Y

2g ′2f2ωµ.

For simplicity f1 = f2 = 0

Higgs boson localized at �1�sites



Mass Matrix for the spin-1 sector

Mneutral =v2

4

(1 + α2)g2 −α2gg2 −gg ′ 0−α2gg2 α2g22 0 0−gg ′ 0 (1 + α2)g ′2 −α2g ′g20 0 −α2g ′g2 α2g ′2

Mcharged =

v2

4

[(1 + α2)g2 −α2gg2−α2gg2 α2g22

]

M = αvg22

We chose α = 4π

Λ = αv is the scale at whichvector resonances get mass

It is natural to take Λ = 4πv

After choosing the value of α we have only one free parameter: M



Mass Eigenstates (g/g2, g′/g2 << 1 limits)

A =g ′√

g2 + g ′2W 3 +

g√g2 + g ′2

B

+gg ′

g2√g2 + g ′2

ρ3 +gg ′

g2√g2 + g ′2

ω

Z =g√

g2 + g ′2W 3 − g ′√

g2 + g ′2B

+g2

g2√g2 + g ′2

ρ3 − g ′2

g2√g2 + g ′2

ω

W± = W± +g

g2ρ±

ρ0 = − g

g2W 3 + ρ3

ω = −g′

g2B + ω

ρ± = ρ± − g

g2W±



Results from 2006: enhancement in Higgs-strahlung channel

AZ,Eur. Phys. J. C 46 (2006) 791u,d

u,d

ZH

Z

u,d

u,d

ρ0H

Z

u,d

u,d

ω0H

Z

u

d

W+ H

W+

u

d

ρ+ H

W+

Mρ (GeV)

σ−σsm

σsm

500450400350300250200

1.4

1.2

1

0.8

0.6

0.4

0.2

0

Figure: pp− >W+h√s = 14 TeV



Update

Is the prediction of an enhancement in the Higgs-strahlung channelstill valid today ?

We decided to update our results

Oscar Castillo-Felisola, Cristóbal Corral, Marcela González,Gastón Moreno, Nicolás A. Neill, Felipe Rojas,

Jilberto Zamora and AZarXiv:1308.1825


Simple Model Limits based on dijet spectrum

Invariant Mass Dijet Spectrum and Limits on M

We implemented themodel in CalcHEP

We generated events forpp− > jj at

√s = 8 TeV

We extracted theresonant cross sectionand applied theappropriate cuts.

We compared withATLAS limits (

√s = 8,∫

Ldt = 13.0 fb−1)






√s = 8 TeV



√s = 8,∫

Ldt = 13.0 fb−1)

Mjj(GeV)

Nu

mb

er

of

Ev

en

ts (

arb

itra

ry u

nit

s)

0

250

500

750

1000

1250

1500

1750

2000

1000 1500 2000 2500 3000 3500






√s = 8 TeV



√s = 8,∫

Ldt = 13.0 fb−1)

Mjj(GeV)

Nu

mb

er

of

Ev

en

ts (

arb

itra

ry u

nit

s)

0

50

100

150

200

250

300

350

400

450

2500 2600 2700 2800 2900 3000 3100 3200 3300 3400 3500






√s = 8 TeV



√s = 8,∫

Ldt = 13.0 fb−1)

σ × Acceptance (pb)

10−3

0,01

0,1

M (GeV)

1800 2000 2200 2400 2600 2800 3000


Simple Model h → γγ

h→ γγ

We compute

Rγ =Γ(h→ γγ)Model

Γ(h→ γγ)SM

It receives extra contributionfrom the ρµ running intoloops. The contribution isformally equal to the Wµ

contribution except that issuppressed by a W -ρ mixingfactor.


Simple Model h → γγ

h→ γγ

We compute

Rγ =Γ(h→ γγ)Model

Γ(h→ γγ)SM

It receives extra contributionfrom the ρµ running intoloops. The contribution isformally equal to the Wµ

contribution except that issuppressed by a W -ρ mixingfactor.

Rγ

1.2

1.3

1.4

1.5

1.6

1.7

1.8

M (GeV)

2200 2400 2600 2800 3000


Simple Model Higgs-strahlung

Higgs-strahlung

Z h

W⁺ hσModel/σSM

0

0.02

0.04

0.06

0.08

0.1

M (GeV)

2200 2400 2600 2800 3000


A Not So Simple Model

More complicated models are Possible

Claudio Dib, Antonio Cárcamo, AZ, ArXiv:1304.0286

Gauge Structure

SU(2)L × SU(2)R︸︷︷︸ × SU(2)C × SU(2)D︸︷︷︸⊃ HLS

[SU(2)L × U(1)Y ]Local




BSM Spectrum

1 Vector (Vµ)

1 Axial-Vector (Aµ)

1 light scalar: �Higgs� (h)

1 heavy scalar (H)

1 heavy pseudo scalar (η)

Comment

This is a more MWT-inspired spectrum




Some Characteristics of the model

Additional non-standard W -B mixing

it helps to the consistency with precision parameters S , T and U forappropriate values of κ = MV /MA

Hierarchy between the mass of the light scalar and the mass of theheavy ones is produced by loop corrections (not put by hand)

nice concordance with ATLAS for h→ γγ

Again h is weakly coupled to V and A (result of the model)




h→ γγ

0.60 0.65 0.70 0.75 0.80 0.85 0.90 0.95

0.0

0.5

1.0

1.5

2.0

Κ

RΓΓ


Comments and Conclusions

Comments and Conclusions

A few years ago we wanted to predict big impressive New Physicssignals

Now we are trying to hide our New Physics

The Simple Model is surprisingly consistent with LHC measurements

Reasons:

The Higgs is weakly coupled to the resonances (form factors ?)We have chosen Λ ≈ 3 TeV

More complicated things can be done but the big picture is there


Further thoughts

Further thoughts

During medieval times, the educated European circles acceptedwithout problem a spherical earth.Indeed, they had a model based on symmetry

Questions

Are antipodeans possible ? (I'm one)

Monsters ?


Further thoughts

When the European explorers crossed the Equator they didn't �ndmonsters

A better understanding of gravity explained the lack of anomaly

We are also crossing a barrier (the TeV barrier) and it seems there isnot monsters

LEP already gave an alert about the absence of monsters

Maybe a new better understanding (gravity again ?) may solve theparadox

or maybe we should look at the world upside down:


Higgs Phenomenology in a Simple Model with Vector Resonances...

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