minimal electroweak scale cosmology and the lhc m.j. ramsey-musolf wisconsin-madison npac...

Minimal Electroweak Scale Cosmology and 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

Berkeley, March 2009

Outline

I. Intro & Motivation

II. Baryogenesis & EWPT

III. Three minimal models & their LHC phenomenology

• Real Singlet xSM

• Complex Singlet cxSM

• Real Triplet SM

V. Barger, P. Fileviez Perez, H. Patel, P. Langacker, M. McCaskey, D. O.Connell, S. Profumo, G. Shaugnessy, K. Wang, M. Wise

Minimal TeV-scale SM extensions

• Can help explain the origin of matter (visible and dark)

• Can be discovered at the LHC

• Can be probed in cosmologically relevant parameter space at colliders

Cosmology at the HEP & NP Interface

• Nature of DM & its interactions

• Origin of the BAU

Two puzzles:

Additional problems:

• Gauge hierarchy

• EWPO & mH (little hierarchy)

• Origin of m

Indirect & direct detection

Collider E

Collider: EWPT & spectrum

EDM: CPV

Non-minimal Solutions (SUSY)

Nature of DM & its interactions

Origin of the BAU

Gauge hierarchy

EWPO & mH

Origin of m

“Minimal” : 105 new parameters

Additional complications:

• Why is ~ Mweak ?

• Why little flavor & CPV ?

• Origin of params in Lsoft ?

• MSUSY < TeV (hierarchy)

• Bino-Higgsino-like LSP (DM)

• Light RH stop ( m < 125 GeV)

• M1 ~

Minimal Solutions (non-SUSY)

Nature of DM & its interactions

Origin of the BAU

Gauge hierarchy

EWPO & mH

Origin of m

Extra Scalars Extra Fermions

• Set aside hierarchy problem (for now)

• To what extent can minimal scenarios for new electroweak scale physics help explain the abundance of matter (visible & dark) ?

• How can they be probed at the LHC ?

This Talk

Highlight for This Talk: Scalars

Gauge Interactions

No Gauge Interactions

Simplest: 1 new dof

Next Simplest: 2 new dof

Focus: Key parameters for cosmo & LHC pheno

Complex Singlet (cxSM):DM, BAU, and mH / EWPO

H-S Mixing, Reduced BRs, & SI

Real Singlet (xSM):DM or BAU-mH / EWPO

BAU: H-S Mixing & Reduced BRs

DM: Reduced BRs & SI

Simplest: 3 new dof (2HDM: 4 new dof)

Real Triplet SM)DM or BAU (EWPT)

DM: Charged track & SI

BAU: or bb; Br(H!)

Baryogenesis: Ingredients

Anomalous B-violating processes

Prevent washout by inverse processes

Sakharov Criteria

• B violation

• C & CP violation

• Nonequilibrium dynamics

Sakharov, 1967

SM Sphalerons:

SM CKM CPV:

SM EWPT:

EDMs

LHC: Scalars

Electroweak Phase Transition & Higgs

?

φ

?

φ

?

F

?

F1st order 2nd orderLEP EWWG

Increasing mh

mh>114.4 GeV

or ~ 90 GeV (SUSY)

Computed ESM : mH < 70 GeV

Need

So that sphaleron is not too fast

EMSSM ~ 10 EpertSM : mH < 120 GeV€

€

€

˜ t

€

+LStop loops in VEff

Light RH stop w/ special

Non-doublet Higgs (w / wo SUSY)

€

S

€

Mixing€

S

€

€

S

Decay





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

€

e+

€

e−

€

Z 0

€

Z 0

€

€

S

sin2

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

• Goal: identify generic features of minimal models with new scalars having a strong, 1st order EWPT and/or DM

• Determine low-energy phenomenology (Higgs studies, precision ewk)

• Address CPV with a different mechanism

Finite Temperature Potential

?

φ

?

φ

?

F

?

F

€

H 0

€

S

• What is the pattern of symmetry breaking ?

• What are conditions on the couplings in V(H,S) so that <H0>/T > 1 at TC ?

Cylindrical Co-ordinates

€

€

α • Compute Veff (αT )

• Minimize w.r.t α

• Find TC

• Evaluate v(TC )/TC ~

cos α(TC) (TC )/TC

VEFF (T) & EWSB

Potential

Key Parameters

Analytic

Analytic

Numerical€

h2

€

h1

€

h2

€

e+

€

e−

€

Z 0

€

Z 0

€

€

S

Strong first order EWPT: SMStrong first order EWPTIncrease

Large e < 0

Reduce

Nonzero V0

a1<0, a2 either sign

Light: all models Black: LEP allowed

a1=b3= 0, a2 < 0

Symmetry Breaking

Two Cases for <S>at high T:

?

φ

?

φ

?

F

?

F

€

H 0

€

S

€

€

α

Vmin = 0

Vmin = V0 < 0

LHC Phenomenology

Signatures





EWPO compatible

m2 > 2 m1

m1 > 2 m2

LHC: reduced BR(h SM)

€

h1

€

h2

€

h1€

b

€

b

€

€

Signal Reduction Factor

Production Decay



CMS 30 fb-1

SM-like

Singlet-like

SM-like

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

~ EWB Viable

Light: all models Black: LEP allowed

Scan: EWPT-viable model parameters

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

h2

€

h1

€

h2



EWPO comp w/ a1=0=b3



LHC: reduced BR(h SM)



Probing : WBF

H ! ZZ! 4 l

H ! WW! 2j l

• Early LHC discovery possible

• Determine as low as ~ 0.5

Complex Singlet: EWB & DM

Barger, Langacker, McCaskey, R-M, Shaugnessy: 0811.0393 [hep-ph]



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

No domain walls DM mass



No CPV for T < TEW : Stable A

Spontaneous CPV for T ~ TEW ?

Complex Singlet: EWB & DM

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







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

Complex Singlet: Direct Detection

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

Little sensitivity of scaled SI to







Complex Singlet: LHC Discovery

Barger, Langacker, McCaskey, R-M, Shaugnessy

Traditional search: CMS





Invisible search: ATLAS

Single component case (x0 = 0)

EWPT

€

h j

€

A

€

A

VBF: Invisible Search I

Central Jet Veto

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


are needed to see this picture.QuickTime™ and a

decompressorare needed to see this picture.

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

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



Large pT (invisible decay)

Dijet azimuthal distribution



Cahn et al ‘87

Complex Singlet: LHC Discovery

Barger, Langacker, McCaskey, R-M, Shaugnessy

Traditional search: CMS





Invisible search: ATLAS

Single component case (x0 = 0)

EWPT

€

h j

€

A

€

A

Combined search



Real Triplet

~ ( 1, 3, 0 )




are needed to see this picture. H1 -> H2H2H- Mixing



Independent Parameters:

v0, x0, 0, a1, a2, b4

Fileviez-Perez, Patel, Wang, R-M: 0811.3957 [hep-ph]

Real Triplet : Key Features

Gauge interactions

Large ! W+W- : Need M ~ 2 TeV for full CDM

parameterSmall x0(T=0) : Small mixing & EWPO impact

“Fermiophobic”1st order EWPT ?

SpectrumFour scalars : H1 ~ SM-like; H2 ~ triplet-like; H+, H-

Couplings & 2BRs

H1H+H- & H2W+W- : Strong a2-dependence ! Sensitivity of BR(Hj!)

Real Triplet : Production

Pair production dominant

Assoc production suppressed€

qq → Z*,γ * → H +H−

€

qq → W ±* → H ±H2



Below WZ Threshold

Promising for LHC

€

bb

€

€

bb γγ

€

→ l, πν

Promising for ILC

€

W +W − ZZ

€

W + Z t b

€

H2π + t b

€

H2π + W − Z

Above WZ Threshold

Real Triplet : H+ Decays

Charged: decay length



Secondary vertex

€

H ± → H2W±*→ H2π ±

Tiny x0 : pure gauge

DM Limit: x0=0 & c = 5.06 cm

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

Real Triplet : Charged BRs I

Charged: x0 dependence





€

H ± → H2W±*→ H2π ±

Pure gauge

€

H ± →W ±Z, f1 f 2 x0 suppressed

Real Triplet : Charged BRs II

Charged: x0 dependence

Below WZ Threshold

Above WZ Threshold





€

H ± → H2W±*→ H2π ±

Pure gauge

€

H ± →W ±Z, f1 f 2 x0 supressed

Real Triplet : General Search I

€

qq → W ±* → H ±H2

€

qq → Z*,γ * → H +H−

Cuts: min pT()> 25 GeV max pT()> 50 GeV| | < 2.8 R > 0.4

Basic signature: (large x0) or b b (small x0)





| M - MH2 | < 5 GeV

Identification:

For bb: b-tagging, pT(b)> 15 GeV, |(b)| < 3.0

For soft from hadronic decay ! Leptonic decay w/ 5 GeV < pT(l) < 40 GeV, |(l)| < 2.8, ET > 20 GeV,

edge of MT



Real Triplet : General Search II

€

qq → W ±* → H ±H2

€

qq → Z*,γ * → H +H−

Basic signature: or b b

a2 = 1, 0, -1 :

Small x0 :

Large x0 :QuickTime™ and a decompressor


a2-dependence of H2W+W- coupling

Real Triplet : Couplings

H2 WW Coupling

H1 H+ H- Coupling:







(H1!) depends on a2 via H+H- loops

(H2!) depends on a2 via W+W- loops

Real Triplet : Neutral BRs

Neutral: differences with SM Higgs & a2 dependence







Different ratio of WW and ZZ, BRs

Real Triplet : H1 Decays

Neutral SM-like Higgs: H+ loops and BR ( H1!)

X0=0: DM case





X0>0: EWPT case

Real Triplet : Summary

Parameters relevant for EWPT: x0 , a1 , a2

H+ mass & decays: x0 , a1 H1,2 WW coupling via : a2





DM Search: ~ 50 events for CDM ~ 0.1 (M ~ 500 GeV); study BR(H1 !)



Summary

Gauge Interactions

No Gauge Interactions

Simplest: 1 new dof

Next Simplest: 2 new dof Complex Singlet (cxSM):DM, BAU, and mH / EWPO

H-S Mixing, Reduced BRs, & SI

Real Singlet (xSM):DM or BAU-mH / EWPO

BAU: H-S Mixing & Reduced BRs

DM: Reduced BRs & SI

Simplest: 3 new dof (2HDM: 4 new dof)

Real Triplet SM)DM or BAU (EWPT)

DM: Charged track & SI

BAU: or bb; Br(H!)

Minimal TeV-scale SM extensions

• Can help explain the origin of matter (visible and dark)

• Can be discovered at the LHC

• Can be probed in cosmologically relevant parameter space at colliders

minimal electroweak scale cosmology and the lhc m.j. ramsey-musolf wisconsin-madison npac...

Documents

w w loopsreal triplet

atlasreal triplet

gevreal triplet

lreal triplet

h2w w couplingreal triplet

x0 dependencereal triplet

hepphreal triplet

shaugnessytraditional