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Phenomenology of Warped Models with Custodial Symmetry. José Santiago Fermilab. Budapest, June 27, 2007. Outline. Motivation (... hope you were at Eduardo’s talk!) What to expect: Bosonic spectrum Fermionic spectrum Capturing the essentials: SM + vector-like quarks
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Phenomenology of Warped Models with Custodial Symmetry José Santiago Fermilab Budapest, June 27, 2007
Outline • Motivation (... hope you were at Eduardo’s talk!) • What to expect: • Bosonic spectrum • Fermionic spectrum • Capturing the essentials: SM + vector-like quarks • The model: Bidoublets and singlets • Low energy effects and decay channels • Phenomenological implications: • Fermion discovery • Implications for Higgs physics • Vector boson discovery • Conclusions
Motivation • Warped models with custodial symmetry: • Natural theory of EWSB • Compelling theory of flavor • Realistic models (custodial protection of Zbb) have very characteristic spectrum • Randall-Sundrum phenomenology revisited: • New vector-like fermions • Discovery of the fingerprints of custodial protection • Implications for Higgs physics • Implications for discovery of vector resonances Agashe, Delgado, May, Sundrum JHEP (03) Agashe, Contino, Da Rold, Pomarol PLB (06)
What to expect? • Bosonic spectrum • Tower of bosonic resonances • Fermionic spectrum • Naturalness (cancellation of top loops) and custodial protection of Zbb predict light quarks with well defined quantum numbers that mix strongly with third generation quarks Carena, Pontón, J.S., Wagner NPB(06) + hep-ph/0701055
What to expect? • Bosonic spectrum • Tower of bosonic resonances • Fermionic spectrum • Naturalness (cancellation of top loops) and custodial protection of Zbb predict light quarks with well defined quantum numbers that mix strongly with third generation quarks
Capturing the essentials • Extend the SM with the relevant vector-like quarks • With mass matrix (assume no mixing to b)
Capturing the essentials • Extend the SM with the relevant vector-like quarks • With mass matrix (assume no mixing to b)
Capturing the essentials • Extend the SM with the relevant vector-like quarks • With mass matrix (assume no mixing to b)
Low Energy Effects • Top (bottom) couplings
Low Energy Effects Particular (but well motivated) limit: degenerate bidoublet and heavy singlet • Top (bottom) couplings Suppressed low energy effects!!
Main Decay Channels • Singlet • Non-degenerate bidoublet • Charge 2/3 • Charges 5/3 and -1/3
Main Decay Channels • Singlet • Non-degenerate bidoublet • Charge 2/3 • Charges 5/3 and -1/3
Phenomenological implications (I) • Vector-like quark discovery • T has been extensively studied (recently in LH models) • Bidoublets have been less studied (but are far more interesting!) • Exotic decay channels • Large BR of charge 2/3 into Z Dennis, Ünel, Servant, Tseng ‘07
Phenomenological implications (II) • Implications for Higgs physics • Top Yukawa reduced due to mixing • Reduction of gluon fusion Higgs production • Small enhancement of (not enough to compensate for the decrease in gluon fusion) Recall vector-like quark masses (mostly) not from EWSB small contribution to gluon fusion
Phenomenological implications (II) • Implications for Higgs physics • But new (strong) production mechanisms through decay of vector-like quarks (with large BR into Higgs)
Phenomenological implications (II) • Implications for Higgs physics • But new (strong) production mechanisms through decay of vector-like quarks (with large BR into Higgs) Aguilar-Saavedra JHEP (06) • 8 fb-1 can allow for a 5σ Higgs discovery for mH=115 GeV and a vector-like singlet T with MT=500 GeV • Better prospects for bidoublets!
Phenomenological implications (III) • Discovery of KK gluons • Studies done assuming gluons decay only to (RH) tops • Very hard tops, pT~TeV, difficult to reconstruct (top jets) • Realistic models have a richer structure (new decay channels open) • Not all tops come directly from the KK gluon (can miss peak) • New decays produce softer tops (easier to reconstruct) • If light bidoublets: large number of fermions with strong coupling to KK gluons very wide resonance (BKTs probably necessary) Agashe, Belyaev, Krupovnickas, Perez, Virzi ph/0612015 Lillie, Randall, Wang ph/0701166 Lillie, Su, Tait, to appear
Phenomenological implications (III) • Discovery of KK gluons
Phenomenological implications (III) • Discovery of KK gluons
Phenomenological implications (III) • Discovery of KK gluons
Conclusions • Realistic models with warped extra dimensions have a very rich fermionic spectrum • SM+ vector-like quarks captures the main features • Time to revisit RS phenomenology • New fermions as fingerprints of custodial symmetry • Implications for Higgs physics • Implications for the discovery of bosonic resonances