Electroweak Phase Transition, Scalar Dark Matter, & the LHC

Electroweak Phase Transition, Scalar Dark Matter, & the LHC

M.J. Ramsey-MusolfWisconsin-MadisonQuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.

QuickTime™ and a decompressor

are needed to see this picture.

http://www.physics.wisc.edu/groups/particle-theory/

NPACTheoretical Nuclear, Particle, Astrophysics & Cosmology

TNT Colloquium, November 2012



Recent Work• M. Gonderinger, Y. Li, H. Patel, & MRM, arXiv:1202.1316

• M. Buckley & MRM JHEP 1109 (2011) 094

• H. Patel & MRM, JHEP 1107 (2011) 029

• C. Wainwright, S. Profumo, MRM Phys Rev. D84 (2011) 023521

• M. Gonderinger, H. Lim, & MRM, Phys. Rev. D86 (2012) 043511

• W. Chao, M. Gonderinger, & MRM, arXiv:1210.0491

Earlier Work

• D. O’Connell, MRM, & M.B. Wise, PR D75 (2007) 037701

• S. Profumo, MRM, & G. Shaugnessy, JHEP 0708 (2007) 010

• V. Barger, P. Langacker, M. McCaskey, MRM, & G. Shaugnessy, PR D77 (2008) 035005, D79 (2009) 015018

• P. Fileviez-Perez, H. Patel, MRM & K. Wang, PR D79 (2009) 055024

Stuart J. Freedman



Outline

I. Intro & Motivation

II. EWPT & General Features

III. Three minimal extensions of the Standard Model scalar sector

IV. ( How will we know it’s a scalar ? )

V. ( Theoretical issues )

I. Intro & Motivation

Scalar Fields in Cosmology

What role do scalar fields play (if any) in the physics of the early universe ?

Dark Matter Portals



Standard Model Hidden Sector (DM)

Scalar Fields & the Higgs Portal



Scalar Fields in Particle Physics

Scalar fields are a simple

Has a fundamental scalar finally been discovered ?

Scalar fields are theoretically problematic

€

H 0

€

H 0

€

ϕ NEW

m2 ~ 2

If so, is it telling us anything about ?

What is the BSM Energy Scale ?

Remarkable agreement with EWPO



EWPO: data favor a “light” SM-like Higgs scalar



Tension: EWPO + Direct Searches

What is the BSM Energy Scale ?

Remarkable agreement with EWPO



Agreement w/ SM at ~ 10-3 level: ONP = c / 2



~ 10 TeV generically

Barbieri & Strumia ‘99



Must BSM ~ TeV to maintain a weak scale scalar ?


€

H 0

€

H 0

€

ϕ NEW

m2 ~ 2

EWPO: for new interactions coupling to gauge bosons or fermions, BSM >> TeV



Must BSM ~ TeV to maintain a weak scale scalar ?


€

H 0

€

H 0

€

ϕ NEW

m2 ~ 2

Perhaps new weak scale physics couples only to scalar sector: “Higgs portal”


Problem Theory Exp’t

• Inflation

• Dark Energy

• Dark Matter

• Phase transitions



Scalar Fields & Cosmic History

Standard Model Universe

EW Symmetry Breaking: Higgs ?

New Scalars ?

QCD: n+p! nuclei

QCD: q+g! n,p…

Astro: stars, galaxies,..



Scalar Fields & Inflation



New Scalars ?

QCD: n+p! nuclei

QCD: q+g! n,p…


• Flatness

• Isotropy

• Homogeneity







Scalar Field: Inflaton

“Slow roll”

Reheat



Scalar Fields & Dark Energy

?

• CDM

• Supernovae

• BAOQuickTime™ and a

decompressorare needed to see this picture.




are needed to see this picture. > 0

Cosmological constant ?

Scalar Field: Quintessence ?



Scalar Fields & the Origin of Matter

?

Baryogenesis: When? CPV? SUSY? Neutrinos? Non-equilibrium dynamics or CPT violation?

• BBN ( t ~ 100 s )

• CMB ( t ~ 105 y )








?


• BBN ( t ~ 100 s )

• CMB ( t ~ 105 y )





Electroweak Phase Transition ? New Scalars




? ?

Darkogenesis: When? SUSY? Neutrinos? Axions ? YB related ?






• Rotation curves

• Lensing

• Bullet clusters

Electroweak Phase Transition ? New Scalars




? ?

Darkogenesis: When? SUSY? Neutrinos? Axions ? YB related ?






• Rotation curves

• Lensing

• Bullet clusters

Electroweak Phase Transition ? New Scalars: CDM ?


• Inflation

• Dark Energy

• Dark Matter



?

?

?

?


• Inflation

• Dark Energy

• Dark Matter



?

?

?

?

Could experimental discovery of a fundamental scalar point to early universe scalar field dynamics?


• Inflation

• Dark Energy

• Dark Matter



?

?

?

?

Focus of this talk, but perhaps part of larger role of scalar fields in early universe

Questions for this Talk:

• Was there a cosmic phase transition at T ~ 100 GeV ?

• Did it have the characteristics needed for successful electroweak baryogenesis and/or production of gravity waves?

• Are its dynamics coupled to dark matter ?

• What are the experimental signatures ?

• How robust is the underlying theory ?

II. General Features

Effective Potential

L = (D y D - V( )

Tree level

V( ) ) VEFF( ,T)

Quantum corrections

* Many applications: Effective action

*

• T=0 : Coleman-Weinberg (RG improved)

• T>0 : Finite-T effective potential

EW Phase Transition: New Scalars

?

?

?

F

?

F1st order 2nd order

Increasing mh

New scalars


?

?

?

F

?


Increasing mh

New scalars

Baryogenesis Gravity Waves Scalar DM LHC Searches


?

?

?

F

?


Increasing mh

New scalars


“Strong” 1st order EWPT


?

?

?

F

?


Increasing mh

New scalars



Bubble nucleation

EWSB


?

?

?

F

?


Increasing mh

New scalars



Bubble nucleation

EWSBYB : CPV & EW sphalerons

€

Aλ


?

?

?

F

?


Increasing mh

New scalars



Bubble nucleation

EWSBYB : diffuses into interiors

€

Aλ


?

?

?

F

?


Increasing mh

New scalars



Bubble nucleation


Preserve YB

initial

Quench EW sph

€

Aλ


?

?

?

F

?


Increasing mh

New scalars



Bubble nucleation


Preserve YB

initial

Quench EW sph

TC , Esph, Stunnel F(ϕ)


?

?

?

F

?


Increasing mh

New scalars



Bubble nucleation

EWSB

Detonation & turbulence


?

?

?

F

?


Increasing mh

New scalars



Bubble nucleation

EWSB

GW Spectra: Q & tEW

F(ϕ)



?

?

?

F

?


Increasing mh

New scalars



Bubble nucleation

EWSB

GW Spectra: Q & tEW

F(ϕ)




nMSSM

Q

tEW


?

?

?

F

?


Increasing mh

New scalars

Baryogenesis Gravity Waves Scalar DM ? LHC Searches ?


Bubble nucleation

EWSB

TC , Esph, Stunnel

Q & tEW

F(ϕ)

YB preservation, detonation & turbulence

Higgs Boson Searches QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.







SM Higgs?

• SM “background” well below new CPV expectations

• New expts: 102 to 103 more sensitive

• CPV needed for BAU?



LEP, Tevatron, & ATLAS Exclusion Non-SM Higgs(es) ?

LHC Observation

Precision Tests

LHC Exclusion

SM Higgs properties ?



Dark Matter: & SI



Thermal DM: WIMP

SM

SM



Direct detection: Spin-indep DM-nucleus scattering



A

A

III. Simplest Scalar Extensions

Extension EWPT DMDOF

May be low-energy remnants of UV complete theory & illustrative of generic features

Real singlet

Real singlet

Complex Singlet

Real Triplet

1

1

2

3

?

Higgs Portal: Simple Scalar Extensions



Real singlet

Real singlet

Complex Singlet

Real Triplet

1

1

2

3

?

The Simplest Extension

Model

Independent Parameters:

v0, x0, 0, a1, a2, b3, b4

H-S MixingH1 ! H2H2

€

M 2 =μh

2 μhs2 2

μhs2 2 μ s

2

⎛

⎝ ⎜

⎞

⎠ ⎟

Mass matrix

€

h1

h2

⎛

⎝ ⎜

⎞

⎠ ⎟=

sinθ cosθ

cosθ −sinθ

⎛

⎝ ⎜

⎞

⎠ ⎟h

s

⎛

⎝ ⎜

⎞

⎠ ⎟

Stable S (dark matter?)

• Tree-level Z2 symmetry: a1=b3=0 to prevent s-h mixing and one-loop s hh

• x0 =0 to prevent h-s mixingxSM EWPT:

Signal Reduction Factor

Production Decay

Simplest extension of the SM scalar sector: add one real scalar S (SM singlet)



EWPT: a1,2 = 0 & <S> = 0

DM: a1 = 0 & <S> = 0

/ /

O’Connel, R-M, Wise; Profumo, R-M, Shaugnessy; Barger, Langacker, McCaskey, R-M Shaugnessy; He, Li, Li, Tandean, Tsai; Petraki & Kusenko; Gonderinger, Li, Patel, R-M; Cline, Laporte, Yamashita; Ham, Jeong, Oh; Espinosa, Quiros; Konstandin & Ashoorioon…


Model


v0, x0, 0, a1, a2, b3, b4

H-S MixingH1 ! H2H2

€

M 2 =μh

2 μhs2 2

μhs2 2 μ s

2

⎛

⎝ ⎜

⎞

⎠ ⎟

Mass matrix

€

h1

h2

⎛

⎝ ⎜

⎞

⎠ ⎟=

sinθ cosθ

cosθ −sinθ

⎛

⎝ ⎜

⎞

⎠ ⎟h

s

⎛

⎝ ⎜

⎞

⎠ ⎟





Production Decay

EWPT Scenario



Raise barrier Lower TC : a2 < 0

Finite Temperature Potential

?

?

?

F

?

F

€

H 0

€

S

?

?

?

F

?

F

€

H 0

€

S

Multiple fields & new interactions: novel patters of symmetry breaking, lower TC , greater super-cooling, “stronger 1st order EWPT”


Model


v0, x0, 0, a1, a2, b3, b4

H-S MixingH1 ! H2H2

€

M 2 =μh

2 μhs2 2

μhs2 2 μ s

2

⎛

⎝ ⎜

⎞

⎠ ⎟

Mass matrix

€

h1

h2

⎛

⎝ ⎜

⎞

⎠ ⎟=

sinθ cosθ

cosθ −sinθ

⎛

⎝ ⎜

⎞

⎠ ⎟h

s

⎛

⎝ ⎜

⎞

⎠ ⎟





Production Decay

Low energy phenomenology



Raise barrier Lower TC

Mixing Modified BRs

Two mixed (singlet-doublet) states w/ reduced SM branching ratios

Mixed States

h1 = cos h + sin s

h2 = -sin h + cos s

EWPT & LHC Phenomenology

Signatures



m2 > 2 m1

m1 > 2 m2

LHC: reduced BR(h SM)


Production Decay

Light: all models Black: LEP allowed

Scan: EWPT-viable model parameters

LHC exotic final states: 4b-jets, + 2 b-jets…

€

h2

€

h1

€

h2

Profumo, R-M, Shaugnessy

€

h1

€

h2

€

h1€

b

€

b

€

€


Signatures





EWPO compatible

m2 > 2 m1

m1 > 2 m2






Production Decay




Signatures





EWPO compatible

m2 > 2 m1

m1 > 2 m2



Production Decay






EWPO comp w/ a1=0=b3






Signatures





EWPO compatible

m2 > 2 m1

m1 > 2 m2



Production Decay






EWPO comp w/ a1=0=b3






CMS 30 fb-1

SM-like

Singlet-like

SM-like

SM-like w/ H2 ->H1H1 or Singlet-like

Barger, Langacker, McCaskey, R-M, Shaugnessy


Model


v0, x0, 0, a1, a2, b3, b4

H-S MixingH1 ! H2H2

€

M 2 =μh

2 μhs2 2

μhs2 2 μ s

2

⎛

⎝ ⎜

⎞

⎠ ⎟

Mass matrix

€

h1

h2

⎛

⎝ ⎜

⎞

⎠ ⎟=

sinθ cosθ

cosθ −sinθ

⎛

⎝ ⎜

⎞

⎠ ⎟h

s

⎛

⎝ ⎜

⎞

⎠ ⎟





Production Decay

DM Scenario



DM & SI




are needed to see this picture.+ +…QuickTime™ and a


DM PhenomenologyRelic Density



He, Li, Li, Tandean, Tsai



Direct Detection





New Scalars & BSM

Preserving EW Min “Funnel plot”


are needed to see this picture.QuickTime™ and a


VEFF

perturbativity

mH

top loops

naïve stability scale

EW vacuum

Gonderinger, Li, Patel, R-M

SM stability & pert’vity

SM unstable above ~ 108 TeV



top loops sets mH

New Scalars & BSM

Preserving EW Min “Funnel plot”




VEFF

perturbativity

mH

top loops


EW vacuum



top loops


SM stability & pert’vity

SM + singlet: stable but non-pertur’tive

DM-H coupling

Dark Matter StabilityPreserving EW Min



“Funnel plot”





VEFF

perturbativity

mH ?



s

Z2-breaking vacuum

Z2-preserving EW vacuum

No DM: Z2-breaking vac

top loops


EW vacuum

mS2 = b2 + a2 v2

LHC & Higgs Phenomenology



Invisible decays


Look for azimuthal shape change of primary jets (Eboli & Zeppenfeld ‘00)

Dijet azimuthal distribution

€

h j

€

A

€

A

LHC discovery potential


Production Decay



ATLAS




Giardino et al:

arXiv 1207:1347




Real singlet

Real singlet

Complex Singlet

Real Triplet

1

1

2

3

?

Complex Singlet: EWB & DM?

Barger, Langacker, McCaskey, R-M Shaugnessy

Spontaneously & softly broken global U(1)

Controls CDM , TC , & H-S mixing

Gives non-zero MA

Complex Singlet: EWB & DM

Barger, Langacker, McCaskey, R-M, Shaugnessy 2 controls CDM& EWPT







MH1 = 120 GeV, MH2=250 GeV, x0=100 GeV

decreasing TC



Consequences:

Three scalars: h1 , h2 : mixtures of h & S

A : dark matter

Phenomenology: • Produce h1 , h2 w/ reduced

Reduce BR (hj ! SM)

• Observation of BR (invis)

• Possible obs of SI

Complex Singlet: Direct Detection

Barger, Langacker, McCaskey, R-M, Shaugnessy Two component case (x0=0)

Little sensitivity of scaled SI to







SM Higgs?



Three scalars: h1,2 (Higgs-like)

D (dark matter) LHC: WBF “Invisible decay” search

D

D

€

h j

€

h j

D

D

SM Branching Ratios ?



He et al



Barger, Langacker, McCaskey, RM, Shaugnessy

EWPT



WIMP-Nucleus Scattering

Viable Dark Matter ?



Gonderinger, Lim, R-M

2nd light state• TH < WMAP

• Xenon

• Br(inv) > 0.6

= 1 TeV




Real singlet

Real singlet

Complex Singlet

Real Triplet

1

1

2

3

?

Real Triplet

~ ( 1, 3, 0 )

EWPT: a1,2 = 0 & <> = 0

DM & EWPT: a1 = 0 & <> = 0

/ /

Small: -param

Fileviez-Perez, Patel, Wang, R-M: PRD 79: 055024 (2009); 0811.3957 [hep-ph]

Finite Temperature Potential

?

?

?

F

?

F

€

H 0

€

S

Multi-step EWSB transition:

• Step 1: quench sphalerons

• Step 2: move to EW/DM vac

H. Patel & MRM in progress

Real Triplet

~ ( 1, 3, 0 )Fileviez-Perez, Patel, Wang, R-M: 0811.3957 [hep-ph]

New feature: gauge interactions & direct detection


are needed to see this picture. Y = 2 ( Q - I3 )

gZ / 2 I3 - 4 Q sin2 W

Want Y = 0

Real Triplet

~ ( 1, 3, 0 )Fileviez-Perez, Patel, Wang, R-M: 0811.3957 [hep-ph]

New feature: gauge interactions & LHC production

q

q

W +q

q

Z 0

EW cross sections w/ charged states + ET

Real Triplet : DM Search

Basic signature: Charged track disappearing after ~ 5 cm

SM Background: QCD jZ and jW w/ Z ! & W!l

Trigger: Monojet (ISR) + large ET €

qq → W ±* → H ±H2

€

qq → Z*,γ * → H +H−



Cuts: large ET hard jet One 5cm track

Cirelli et al:



M = 500 GeV:

CDM ~ 0.1

SM Higgs?






SM Branching Ratios ?

Four scalars: h1 (Higgs-like) (dark matter)

(new states)

D

D

€

h j

€

h j

D

D



Fileviez-Perez, Patel, R-M, Wang

€

h j





SM Higgs?




LHC: H !

D

D

€

h j

€

h j

D

D



€

h j









IV. Is it a Scalar ?

Real singlet

Real singlet

Complex Singlet

Real Triplet

Extension EWPT DM

?

DOF

1

1

2

3


Real singlet

Real singlet

Complex Singlet

Real Triplet

Extension EWPT DM

?

DOF

1

1

2

3

Mixed Higgs-like states and/or modified BRs: signal reduction invisible search…


Real singlet

Real singlet

Complex Singlet

Real Triplet

Extension EWPT DM

?

DOF

1

1

2

3

Could be fermionic triplet [e.g., Buckley, Randall, Shuve, JHEP 1105 (2011) 97]. How to distinguish?

Di-Jet Correlations



J1

J2

V

V

p1

p2

Buckley, R-M JHEP 1109 (2011) 094



R-hadrons from gg fusion

Scalars

Fermions

Di-Jet Correlations



J1

J2

V

V

p1

p2

Buckley, R-M JHEP 1109 (2011) 094

M2

M1

Mpair





A3 / |Mpair | 2 > 0Scalars:

• Abelian

• Non-ableian for large

Fermions: A3 < 0

V. Theoretical Issues

Gauge-dependence in VEFF ( , T )

VEFF ( , T ) ! VEFF ( , T ; )

Ongoing research: approaches for carrying out tractable, GI computations

• H. Patel & MRM, JHEP 1107 (2011) 029

• C. Wainwright, S. Profumo, MRM Phys Rev. D84 (2011) 023521

• H. Gonderinger, H. Lim, & MRM, arXiv:1202.1316

Origin of Gauge Dependence

Effective Action

Effective Potential

Source term:

Not GI

Nielsen Identities

Identity:

Extremal configurations:

Effective potential:



Baryon Number Preservation “Washout factor”

F()

ln S ~ A(TC) e

Two qtys of interest:

• TC from Veff

• Esph from eff

Baryon Number Preservation: Pert Theory

~

F()

Conventional treatments

Gauge Dep

• GI TC from hbar exp, Veff (ϕϕ), or Hamiltonian formulation

• Use GI scale in Esph computation

H. Patel & MRM, JHEP 1107 (2011) 029“Baryon number preservation criterion” (BNPC)

Nielsen Identities: Application to TC

Critical Temperature

Veff (min , TC) = Veff ( , TC)

Apply consistently order-by-order in

Implement minimization order-by-order (defines ϕn )

Fukuda & Kugo ‘74: T=0 VEFF

Laine ‘95 : 3D high-T Eff Theory

Patel & R-M ‘11: Full high T Theory

Obtaining a GI TC

Track evolution of minima with T using expansion



Track evolution of different minima with T using

n=1

n=2 n=3

Patel & R-M ‘11

Illustrative results in SM:



Full ϕ

Gravity Waves from EWPT: Pert Theory



Abelian Higgs Model

C. Wainwright, S. Profumo, R-M Phys Rev. D84 (2011) 023521 arXiv:1104.5487[hep-ph]



Vacuum Stability & Gauge DependenceComplex Singlet Model

M. Gonderinger, H. Lim, M. R-M arXiv:1202.1316 [hep-ph]

?

?

?

F

?

F

€

H 0

€

S

Possible runaway direction for 2 < 0 (EWPT)



Tree-level stability

Full VEFF (1-loop): -dependence

GI Stability Condition



Use -fns

Conclusions

• Cosmology loves scalar fields (inflation): given observation of a fundamental scalar, perhaps scalar fields can address a number of questions about the early universe

• Simple extensions of the SM scalar sector and lead to observable (SI , LHC) particle dark matter and/or EWPT with interesting implications: baryogenesis, GW, new Higgs states/modified Higgs properties….

• Perhaps observation of these scalars will point to a richer structure for scalar fields in the early universe involving both visible and dark physics

Back Up Slides




Invisible decays






€

h j

€

A

€

A



(h!SS)=0 Invis search



Production Decay




Invisible decays






€

h j

€

A

€

A



Production Decay

Complex Singlet: LHC Discovery


Traditional search: CMS





Invisible search: ATLAS

Single component case (x0 = 0)

EWPT

€

h j

€

A

€

A

Baryon Number Preservation: Pert Theory

~

F()

Conventional treatments

“Baryon number preservation criterion” (BNPC)

DM & Higgs PhenomenologyRelic Density





Vac stability



€

h j

€

A

€

A

Nielsen Identities: Example

General SU(N) theory:General SU(N) theory:



Scalars: physical & WB GB

T & L gauge bosons

Scalar gauge bosons

FP Ghosts

Use ϕ0 : mA2(ϕ0)ij & Mij

2(ϕ0) simultaneously diagonalizable & eigenvalues in distinct subspaces ! -dependent WB GB, scalar gauge, & FPG terms cancel

Patel & R-M ‘11


• Inflation

• Dark Energy

• Dark Matter





Scalar Fields & Cosmic History



New Forces ?

QCD: n+p! nuclei

QCD: q+g! n,p…


BBN and YB





CMB and YB





Cosmic Baryon Asymmetry

?

Baryogenesis: When? CPV? SUSY? Neutrinos?

Big Bang Nucleosynthesis:

Light element abundances depend on YB



Cosmic Baryon Asymmetry

?

Baryogenesis: When? CPV? SUSY? Neutrinos?

Cosmic Microwave Bcknd:

Shape of anisotropies depends on YB

VBF: Invisible Search I

Central Jet Veto

H ! W+W- ! jj : ideally only W decay products in central region (Chehime & Zeppenfeld ‘93)




H ! W+W- ! l + l - : central region minijet from SM bcknd, separation from dilepton pair (Barger, Phillips, Zeppenfeld ‘94)

VBF: Invisible Search II

pT (H) distribution



Large pT (invisible decay)





ϕ

Cahn et al ‘87





Key features for EWPT & DM: (1) Softly broken global U(1)

(2) Closes under renormalization

(3) SSB leading to two fields: S that mixes w/ h and A is stable (DM)





Key features for EWPT & DM: (1) Softly broken global U(1)

(2) Closes under renormalization

(3) SSB leading to two fields: S that mixes w/ h and A is stable (DM)

Controls CDM& EWPT

Normalized Latent Heat

Peak amplitude:

GW Spectra (detonations):

Peak frequency:





See, eg, Caprini, Durrer, Servant ‘08; Huber & Konstandin ‘08; Caprini et al ‘09; Chung & Zhou ‘10

Electroweak Phase Transition, Scalar Dark Matter, & the LHC

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