Radion flavor in Warped Extra Dimensions. a by Manuel Toharia - - PowerPoint PPT Presentation

Radion flavor in Warped Extra

• Dimensions. a

by

Manuel Toharia

(University of Maryland)

at

PHENO 2009, Madison, May 2009

aBased on arXiv:0812.2489 A.Azatov, M.T., L.Zhu

Outline

• Introduction

– Flavor in RS – The radion in RS

• radion Flavor
• Conclusions

Introduction

• Warped Extra Dimensions: One compact extra dimension with

warped geometry.

• Original setup: Two branes as boundaries and all SM fields on

the TeV Brane → RS1. – Towers of KK gravitons – Radion graviscalar

• More recent setups: Two branes, Higgs field on TeV brane,

SM fields in the “bulk”. – Towers of KK gravitons – Towers of KK SM fields – Radion graviscalar

Flavor anarchy: masses and mixings from fermion localization

The Radion and its interactions

In the RS1 model [Randall,Sundrum,(′98)] the background metric go

AB

is defined by ds2 = e−2σηµν dxµdxν + dy2 = R2 z2

• ηµν dxµdxν + dz2

with σ(y) = ky (and R = 1/k). Hierarchy created between the two boundaries at y = 0 and y = πr0 (z = R and z = R′). The linear metric perturbations hAB(x, y) can be reduced to ds2 =

• e−2σηµν +
• e−2σhTT

µν (x, y) − ηµνr(x)

• dxµdxν +
• 1 + 2e2σr(x)
• dy2

(the graviscalar r(x) is massless. A stabilization mechanism pro- viding it with mass is assumed

for example[Golberger,W ise(′99)])

• Ex. RS1 - Matter on the brane

Sint(r) = 1 Λr

• dx4T µ

µ φ0(x)

Higgs-like couplings! Higgs H Gluon αs 8π

• i

F1/2(τi)/2 − b3

• φ0

Λr GµνGµν γ α 8π

• i

e2

i Ni cFi(τi) − (b2 + bY )

• φ0

Λr FµνF µν W, Z φ0 Λr M2

V V αVα

f φ0 Λr mf ¯ ff αs 8π

• i

F1/2(τi)/2

• H

v GµνGµν α 8π

• i

e2

i Ni cFi(τi)

• H

v FµνF µν H v M2

V V αVα

H v mf ¯ ff

Radion Production vs. Higgs production

200 400 600 800 1000 mφ (GeV) 10

−7

10

−6

10

−5

10

−4

10

−3

10

−2

10

−1

10 10

1

10

2

σ (pb)

gg fusion WW,ZZ fusion Wφ Zφ qq

−, gg −> tt −φ

LHC Tevatron Run2

K.Cheung (’00)(Λφ = 1 TeV) (CMS TDR)

Radion Branchings vs. Higgs Branchings

WW ZZ

gg ΓΓ bb

Ξ0

tt hh

BULK FIELDS RS1 100 200 300 400 500 600 10

5

10

4

0.001 0.01 0.1 1

mΦ

Br ΦXX

Branchings of the radion vs. its mass mφ Branchings of Higgs vs. its mass (from CMS TDR)

LHC REACH in (mφ − Λφ) (with Nobu Okada)

Radion couplings to 5D fermions

• 1 family of bulk fermions and a Brane Higgs: [Csaki,Hubisz,Lee(07)]

φ0 Λr (cQ − cU)mu¯ uu Computation slightly involved, but a way to understand it is look at R′ dependance in fermion mass term: mf ∼ Y v(R/R′)cQ−cU−1 ∼ (1/R′)cQ−cU Radion can be understood as perturbation in the interbrane distance L, or in 1/R′ scale in the conformal frame. So we can write 1/R′ → 1/R′ (1 + φ/Λr) Then include it in mass term and expand linearly in the radion (cQ − cU) φ/Λr (1/R′)cQ−cU ⇒ (cQ − cU) φ/Λr mf

• We extend to 3 families and allow for bulk Higgs (localized

towards IR brane)

[A.Azatov,M.T.,L.Zhu (arXiv:0812.2489)]

φ0 Λr (ci

Q − cj D) mij d ¯

diLdj

R + h.c

φ0 Λr ¯ dL(cQmd − mdcD)dR where md is not in the diagonal physical basis and cQ,D are diagonal matrices. ci

Q,D are the fermion bulk parameters for UV fermions BUT

|ci

Q,D| = 1/2 for IR fermions

(and cQ > 0 and cD < 0). ⇒ tree-level FCNC’s! Diagonalize fermion mass matrix means here φ0 Λr ¯ dphys

L

• (U †cQU) md

diag − md diag (W †cDW)

• dphys

R

In the physical basis we obtain the estimate: LHFV = 1 Λr ad

ij

• md

i md j φ0 ¯

d i

Ldj R + h.c.

ad

ij ∼

     (cQ1 − cD1) (cQ1 − cQ2)λ

• ms

md

G(cQi)λ3

mb md

(cD1 − cD2) 1

λ

• md

ms

(cQ2 − cD2) (cQ2 − 1

2)λ2 mb ms

F(cDi) 1

λ3

• md

mb

(cD2 − cD3) 1

λ2

• ms

mb

(1

2 − cD3)

     where we have taken cQ3 = 1

2 (IR localized) and λ ∼ 0.22 .

F and G are O(.1) functions of the ci’s ⇒ ads ∼ asd ∼ 0.06

Tree level RADION exchange will induce sLdRsRdL with coefficient C4 = adsasdmdms 1 m2

φΛ2 r

⇒ K − ¯ K mixing and ǫK put tight bounds

ads 0.03 ads 0.12 ads 0.5 10 20 50 100 200 500 5000 10000 15000 20000 25000 5000 10000 15000 20000 25000

Radion mass mr GeV

Radion interaction scale r GeV M1

KKG MPlR GeV

Figure 1: Bounds in mφ − Λr plane from ǫK. Here we have called ads ≡

• |adsa∗

sd|. From

[A.Azatov,M.T.,L.Zhu (arXiv:0812.2489)]

Outlook

Maybe LHC discovers one or two neutral scalars, and that’s IT. Is it a Higgs? (or a 2 Higgs doublet model?)

• r is it an RS type scenario? (radion plus a Higgs?)

The Radion is Higgs-like but has special signatures:

• Very narrow width
• Special production process

and we have just seen that

• Probing the size of FV couplings important.
• Without flavor symmetry, mradion >

∼ 20 − 50 GeV

• Flavor at LHC? (r → t c ?)
• Higgs-radion mixing?