work with M. Carena, E. Pontón, C. Wagner

NPB (06) [ph/0607106]

and hep-ph/0701055

+ work in progress

Phenomenology of Warped Models Phenomenology of Warped Models with Custodial Symmetrywith Custodial Symmetry

José SantiagoJosé Santiago

FermilabFermilab

Budapest, June 27, 2007

OutlineOutline

Motivation (... hope you were at Eduardo’s talk!)Motivation (... hope you were at Eduardo’s talk!) What to expect: What to expect:

Bosonic spectrumBosonic spectrum Fermionic spectrumFermionic spectrum

Capturing the essentials: Capturing the essentials: SM + vector-like quarksSM + vector-like quarks The model: Bidoublets and singletsThe model: Bidoublets and singlets Low energy effects and decay channelsLow energy effects and decay channels

Phenomenological implications:Phenomenological implications: Fermion discoveryFermion discovery Implications for Higgs physicsImplications for Higgs physics Vector boson discoveryVector boson discovery

ConclusionsConclusions

MotivationMotivation

Warped models with custodial symmetry:Warped models with custodial symmetry: Natural theory of EWSBNatural theory of EWSB Compelling theory of flavorCompelling theory of flavor Realistic models (custodial protection of Zbb) have Realistic models (custodial protection of Zbb) have

very characteristic spectrumvery characteristic spectrum

Randall-Sundrum phenomenology revisited:Randall-Sundrum phenomenology revisited: New vector-like fermionsNew vector-like fermions

Discovery of the fingerprints of custodial protectionDiscovery of the fingerprints of custodial protection Implications for Higgs physicsImplications for Higgs physics Implications for discovery of vector resonancesImplications for discovery of vector resonances

Agashe, Delgado, May, Sundrum JHEP (03)

Agashe, Contino, Da Rold, Pomarol PLB (06)

What to expect?What to expect?

Bosonic spectrumBosonic spectrum Tower of bosonic resonancesTower of bosonic resonances

Fermionic spectrumFermionic spectrum NaturalnessNaturalness (cancellation of top loops) and (cancellation of top loops) and

custodial protection of Zbbcustodial protection of Zbb predict predict light quarkslight quarks with well defined with well defined quantum numbersquantum numbers that that mixmix strongly strongly with third generation quarkswith third generation quarks

Carena, Pontón, J.S., Wagner NPB(06) + hep-ph/0701055

What to expect?What to expect?

Bosonic spectrumBosonic spectrum Tower of bosonic resonancesTower of bosonic resonances

Fermionic spectrumFermionic spectrum NaturalnessNaturalness (cancellation of top loops) and (cancellation of top loops) and

custodial protection of Zbbcustodial protection of Zbb predict predict light quarkslight quarks with well defined with well defined quantum numbersquantum numbers that that mixmix strongly strongly with third generation quarkswith third generation quarks

Capturing the essentialsCapturing the essentials

Extend the SM with the relevant vector-like Extend the SM with the relevant vector-like quarksquarks

With mass matrix (assume no mixing to b)With mass matrix (assume no mixing to b)

Capturing the essentialsCapturing the essentials

Extend the SM with the relevant vector-like Extend the SM with the relevant vector-like quarksquarks

With mass matrix (assume no mixing to b)With mass matrix (assume no mixing to b)

Capturing the essentialsCapturing the essentials

Extend the SM with the relevant vector-like Extend the SM with the relevant vector-like quarksquarks

With mass matrix (assume no mixing to b)With mass matrix (assume no mixing to b)

Low Energy EffectsLow Energy Effects

Top (bottom) couplingsTop (bottom) couplings

Low Energy EffectsLow Energy Effects

Top (bottom) couplingsTop (bottom) couplingsParticular (but well motivated) limit: degenerate bidoublet and heavy singlet

Suppressed low energy effects!!

Main Decay ChannelsMain Decay Channels

SingletSinglet

Non-degenerate bidoubletNon-degenerate bidoublet Charge 2/3Charge 2/3

Charges 5/3 and -1/3Charges 5/3 and -1/3

Main Decay ChannelsMain Decay Channels

SingletSinglet

Non-degenerate bidoubletNon-degenerate bidoublet Charge 2/3Charge 2/3

Charges 5/3 and -1/3Charges 5/3 and -1/3

Phenomenological implications (I)Phenomenological implications (I)

Vector-like quark discoveryVector-like quark discovery T has been extensively studied (recently in LH T has been extensively studied (recently in LH

models)models)

Bidoublets have been less studied (but are far Bidoublets have been less studied (but are far more interesting!)more interesting!)

Exotic decay channelsExotic decay channels

Large BR of charge 2/3 into Z Large BR of charge 2/3 into Z

Dennis, Ünel, Servant, Tseng ‘07

Phenomenological implications (II)Phenomenological implications (II)

Implications for Higgs physicsImplications for Higgs physics Top Yukawa reduced due to mixingTop Yukawa reduced due to mixing

Reduction of gluon fusion Higgs productionReduction of gluon fusion Higgs production

Small enhancement of (not enough to compensate Small enhancement of (not enough to compensate for the decrease in gluon fusion) for the decrease in gluon fusion)

Recall vector-like quark masses (mostly) not from EWSB small contribution to gluon fusion

Phenomenological implications (II)Phenomenological implications (II)

Implications for Higgs physicsImplications for Higgs physics But new (strong) production mechanisms through But new (strong) production mechanisms through

decay of vector-like quarks (with large BR into decay of vector-like quarks (with large BR into Higgs)Higgs)

Phenomenological implications (II)Phenomenological implications (II)

Implications for Higgs physicsImplications for Higgs physics But new (strong) production mechanisms through But new (strong) production mechanisms through

decay of vector-like quarks (with large BR into decay of vector-like quarks (with large BR into Higgs)Higgs)

Aguilar-Saavedra JHEP (06)

8 fb8 fb-1-1 can allow for a 55σσ Higgs discovery for mHiggs discovery for mHH=115 =115 GeVGeV and a vector-like singlet a vector-like singlet T with MT with MTT=500 GeV=500 GeV

Better prospects for bidoublets!

Phenomenological implications (III)Phenomenological implications (III)

Discovery of KK gluonsDiscovery of KK gluons Studies done assuming gluons decay only to (RH) Studies done assuming gluons decay only to (RH)

topstops Very hard tops, pVery hard tops, pTT~TeV, difficult to reconstruct (~TeV, difficult to reconstruct (top jetstop jets))

Realistic models have a richer structure (new decay Realistic models have a richer structure (new decay channels open)channels open)

Not all tops come directly from the KK gluon (can miss peak)Not all tops come directly from the KK gluon (can miss peak) New decays produce softer tops (easier to reconstruct)New decays produce softer tops (easier to reconstruct) If light bidoublets: large number of fermions with strong If light bidoublets: large number of fermions with strong

coupling to KK gluons very wide resonance (BKTs coupling to KK gluons very wide resonance (BKTs probably necessary)probably necessary)

Agashe, Belyaev, Krupovnickas, Perez, Virzi ph/0612015

Lillie, Randall, Wang ph/0701166

Lillie, Su, Tait, to appear

Phenomenological implications (III)Phenomenological implications (III)

Discovery of KK gluonsDiscovery of KK gluons

Phenomenological implications (III)Phenomenological implications (III)

Discovery of KK gluonsDiscovery of KK gluons

Phenomenological implications (III)Phenomenological implications (III)

Discovery of KK gluonsDiscovery of KK gluons

ConclusionsConclusions Realistic models with warped extra dimensions Realistic models with warped extra dimensions

have a very rich fermionic spectrumhave a very rich fermionic spectrum SM+ vector-like quarks captures the main SM+ vector-like quarks captures the main

featuresfeatures

Time to revisit RS phenomenologyTime to revisit RS phenomenology New fermions as fingerprints of custodial symmetryNew fermions as fingerprints of custodial symmetry Implications for Higgs physicsImplications for Higgs physics Implications for the discovery of bosonic resonancesImplications for the discovery of bosonic resonances