# Presentation: 502668

## Probing the scalar sector with ZZH 

- outline:
- Introduction
- Models:
- 	higher representations
- 	radion (nonSUSY/SUSY)
- Conclusions

- Debajyoti Choudhury, Anindya Datta, Katri Huitu,
- hep-ph/0302141, to appear in Nucl.Phys.B

- WIN'03, Katri Huitu

- Oct, 2003

## Introduction 

- Assume that EWSB due to Higgs mechanism
- Light scalars not taking part in the EWSB can mix with Higgs
- In extensions of the Standard Model new scalars and new representations- spontaneous CP violation, - supersymmetry, - left-right model, - gauge unification,...
- What can a detected set of scalars tell about the model?
- Related works: Burgess et al, IJMP A17(2002) 1841; Ellis et al, PLB 502 (2001) 171; Kane et al PRD 64 (2001) 095013; Ambrosanio et al NPB 624 (2002) 3.

- WIN'03, Katri Huitu

- Oct, 2003

## ZZH coupling

- gets contribution from any nonsinglet VEV
- ZZH coupling essential in Higgs production:                     *    *or gauge boson fusion         use to separate between models

- Lagrangian:

- WIN'03, Katri Huitu

- Oct, 2003

## E.g.  SU(5)  GUT 

- The SM fermions in

- contain neutral scalars

- doublets

- Y=1 triplet

- in minimal SU(5) problems with realistic spectrum    need more representations

- These contain singlets, triplets (Y=0,1),                      4-plets (Y=3/2,1/2), 5-plets (Y=2,1,0)

- WIN'03, Katri Huitu

- Oct, 2003

## A strong constraint from the -parameter,

- experimentally ** 1.  We demand **= 1.

- 4 max (*T*3i2 )   C  4 min (*T*3i2 )

- C  1   BSM Physics

- Parametrize the ZZH coupling:

- WIN'03, Katri Huitu

- Oct, 2003

## fermions of the SM couple to doublets

- Yt increases with decreasing v1/2:

- Yt  RGE:

- Z mass:

- WIN'03, Katri Huitu

- Oct, 2003

## Triplets Added

- fine tuning

- Triplets (3,0) and (3,1)
-   1 < C < 4

- Georgi, Machachek,NPB 262 (1985) 463.

- WIN'03, Katri Huitu

- Oct, 2003

## E.g. in the Georgi – Machachek model, for the fermion widths

- Use the measured value and error to constrain the ratio of VEVs

- For a 90 % C.L. constraint on the ratio,  is 1.64, if  exp has 1 limits.

- WIN'03, Katri Huitu

- Oct, 2003

## Fiveplets added

- (5,0) and (5,1) enhance 
- (5,2) suppresses 
- (5,0) and (5,2):
- 1 < C < 16
- (5,0) and (5,1):
- 1 < C < 12

- WIN'03, Katri Huitu

- Oct, 2003

## Radions in RS scenario

- 5-dim universe, compactify on S1 / Z2

- hidden

- visible

- y=0

- y=

- massless fields: gravitong                          rc                 modulus T(x)
- T(x) has zero potential    stabilize,
- parameters on visible brane scaled by e-krc ,radion    e-k(T-rc), m  O(1 TeV)

- Randall, Sundrum, PRL 83 (1999) 3370, 4690.

- Goldberger, Wise, PRL 83 (1999)4922, PLB475 (2000)275.

- WIN'03, Katri Huitu

- Oct, 2003

## Radion couplings:

- Stress energy tensor:

- Curvature-Higgs mixing
- 

- Giudice, Rattazzi, Wells, NPB 595 (2001) 250;
- Csaki, Graesser, Kribs, PRD 63 (2001) 065002.

- mixing parameter

- WIN'03, Katri Huitu

- Oct, 2003

## Diagonalize  

- Diagonalize  

- positivity of kinetic terms:

- WIN'03, Katri Huitu

- Oct, 2003

## 

- Couplings to physical scalars (V=general gauge boson):

- WIN'03, Katri Huitu

- Oct, 2003

## unitarity bounds

- Han,Kribs,McElrath,
- PRD 64 (2001)076003

- constant C curves

- WIN'03, Katri Huitu

- Oct, 2003

## Supersymmetric RS model

- We consider
- J.A. Casas, J.R. Espinosa, I. Navarro, NPB 620 (2002) 195

- Supplement MSSM with a radion T and
- dilaton S in the bulk (susy breaking along FS):

- To make contact with the superstring theory, the RS model may need to be supersymmetrized.

- Extra dimensions may be connected with the supersymmetry breaking method:
- Stabilization    e.g. AMSB possible.

- Luty, Sundrum,
- PRD 62 (2000) 035008

- WIN'03, Katri Huitu

- Oct, 2003

## The warp factor

- Lagrangian

- note: *K*  is model dependent

- WIN'03, Katri Huitu

- Oct, 2003

## 

- Diagonalize H10,H20,t    sum of the squares of scalar couplings (normalized to SM value):

- Coupling to the singlet radion from the trace of stress-energy tensor:

- WIN'03, Katri Huitu

- Oct, 2003

## Slide 18

- WIN'03, Katri Huitu

- Oct, 2003

## Conclusions

- Sum of the ZZH couplings can be an efficient separator between models
- For scalars in higher representations of SU(2)L, the *** *parameter and perturbativity of the top Yukawa-coupling constrain *C*
- In higher dimensions, the Higgs-curvature mixing may effect *C* strongly

- WIN'03, Katri Huitu

- Oct, 2003