Probing the scalar sector with ZZH Debajyoti Choudhury
Probing the scalar sector with ZZH Debajyoti Choudhury, Anindya Datta, Katri Huitu, hep-ph/0302141, to appear in Nucl. Phys. B outline: Introduction Models: higher representations radion (non. SUSY/SUSY) Conclusions Oct, 2003 WIN'03, Katri Huitu 1
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 A 17(2002) 1841; Ellis et al, PLB 502 (2001) 171; Kane et al PRD 64 (2001) 095013; Ambrosanio et al NPB 624 (2002) 3. Oct, 2003 WIN'03, Katri Huitu 2
ZZH coupling Lagrangian: • gets contribution from any nonsinglet VEV • ZZH coupling essential in Higgs production: or gauge boson fusion use to separate between models Oct, 2003 WIN'03, Katri Huitu 3
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) Oct, 2003 WIN'03, Katri Huitu 4
A strong constraint from the -parameter, experimentally 1. We demand = 1. Parametrize the ZZH coupling: C 1 BSM Physics 4 max (T 3 i 2 ) C 4 min (T 3 i 2 ) Oct, 2003 WIN'03, Katri Huitu 5
Z mass: fermions of the SM couple to doublets Yt increases with decreasing v 1/2: Yt RGE: Oct, 2003 WIN'03, Katri Huitu 6
Triplets Added Georgi, Machachek, NPB 262 (1985) 463. Triplets (3, 0) and (3, 1) fine tuning 1<C<4 Oct, 2003 WIN'03, Katri Huitu 7
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. Oct, 2003 WIN'03, Katri Huitu 8
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 Oct, 2003 WIN'03, Katri Huitu 9
Radions in RS scenario Randall, Sundrum, PRL 83 (1999) 3370, 4690. 5 -dim universe, compactify on S 1 / Z 2 visible hidden y=0 y= massless fields: hmn rc graviton gmn modulus T(x) has zero potential stabilize, Goldberger, Wise, PRL 83 (1999)4922, PLB 475 (2000)275. parameters on visible brane scaled by e-k r radion e-k (T-r ), m O(1 Te. V) c , c Oct, 2003 WIN'03, Katri Huitu 10
Radion couplings: Stress energy tensor: Curvature-Higgs mixing Giudice, Rattazzi, Wells, NPB 595 (2001) 250; Csaki, Graesser, Kribs, PRD 63 (2001) 065002. mixing parameter Oct, 2003 WIN'03, Katri Huitu 11
Diagonalize positivity of kinetic terms: Oct, 2003 WIN'03, Katri Huitu 12
Couplings to physical scalars (V=general gauge boson): Oct, 2003 WIN'03, Katri Huitu 13
constant C curves unitarity bounds Han, Kribs, Mc. Elrath, PRD 64 (2001)076003 Oct, 2003 WIN'03, Katri Huitu 14
Supersymmetric RS model 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 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): Oct, 2003 WIN'03, Katri Huitu 15
The warp factor Lagrangian note: K is model dependent Oct, 2003 WIN'03, Katri Huitu 16
Coupling to the singlet radion from the trace of stress-energy tensor: Diagonalize H 10, H 20, t sum of the squares of scalar couplings (normalized to SM value): Oct, 2003 WIN'03, Katri Huitu 17
Oct, 2003 WIN'03, Katri Huitu 18
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 Oct, 2003 WIN'03, Katri Huitu 19
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