1. April 3, 2003LCWS Amsterdam, Katri Huitu1 Probing the scalar sector with ZZH outline: Introduction Models: higher representations radion (nonSUSY/SUSY) Conclusions Debajyoti Choudhury, Anindya Datta, Katri Huitu, hep-ph/0302141

2. April 3, 2003LCWS Amsterdam, Katri Huitu2 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.

3. April 3, 2003LCWS Amsterdam, Katri Huitu3 ZZH coupling gets contribution from any nonsinglet VEV ZZH coupling essential in production: or gauge boson fusion use to separate between models Lagrangian:

4. April 3, 2003LCWS Amsterdam, Katri Huitu4 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)

5. April 3, 2003LCWS Amsterdam, Katri Huitu5 A strong constraint from the  -parameter, experimentally  1. We demand  = 1. 4 max (T 3i 2 )  C  4 min (T 3i 2 ) C  1  BSM Physics Parametrize the ZZH coupling:

6. April 3, 2003LCWS Amsterdam, Katri Huitu6 fermions of the SM couple to doublets  Y t increases with decreasing v 1/2 : Y t RGE: Z mass:

7. April 3, 2003LCWS Amsterdam, Katri Huitu7 Triplets Added fine tuning Triplets (3,0) and (3,1)  1 < C < 4 Georgi, Machachek,NPB 262 (1985) 463.

8. April 3, 2003LCWS Amsterdam, Katri Huitu8 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

9. April 3, 2003LCWS Amsterdam, Katri Huitu9 Higgs mixing with radions 5-dim universe, compactify on S 1 / Z 2 hidden visible y=0 y=  massless fields:    graviton  g   r c modulus T(x) T(x) has zero potential  stabilize, radion     e -k  (T-r c ), m   O(1 TeV) Randall, Sundrum, PRL 83 (1999) 3370, 4690. Goldberger, Wise, PRL 83 (1999)4922, PLB475 (2000)275.

10. April 3, 2003LCWS Amsterdam, Katri Huitu10 Curvature-Higgs mixing  Diagonalize  Giudice, Rattazzi, Wells, NPB 595 (2001) 250; Csaki, Graesser, Kribs, PRD 63 (2001) 065002.

11. April 3, 2003LCWS Amsterdam, Katri Huitu11 positivity of kinetic terms: Couplings to physical scalars (V=general gauge boson): 

12. April 3, 2003LCWS Amsterdam, Katri Huitu12

13. April 3, 2003LCWS Amsterdam, Katri Huitu13 unitarity bounds Han,Kribs,McElrath, PRD 64 (2001)076003 constant C curves

14. April 3, 2003LCWS Amsterdam, Katri Huitu14 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 F S ): 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

15. April 3, 2003LCWS Amsterdam, Katri Huitu15 Lagrangian The warp factor note: K is model dependent

16. April 3, 2003LCWS Amsterdam, Katri Huitu16  Diagonalize  H 1 0,H 2 0,t   sum of the squares of scalar couplings (normalized to SM value): Coupling to the singlet radion from the trace of stress-energy tensor:

17. April 3, 2003LCWS Amsterdam, Katri Huitu17

18. April 3, 2003LCWS Amsterdam, Katri Huitu18 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