Spectrum and couplings of Spectrum and couplings of SO(5)SO(5)xxU(1) U(1)

gauge-Higgs unification model gauge-Higgs unification model in warped spacetimein warped spacetime

Yutaka Sakamura (Osaka Univ.)with Yutaka Hosotani (Osaka Univ.)

Phys.Lett.B645 (2007) 442

March 2, 2007@KEK

B-L

IntroductionStructure of EW ： unspecified yetStandard Higgs mechanism Little Higgs model

(N.Arkani-Hamed, et al., JHEP 0208 (2002) 021 )

Higgsless model (C.Csaki, et al., PRD69 (2004) 055006)

Gauge-Higgs unification model (GHU)(N.Manton, NPB158 (1979)141, D.B.Fairlie, PLB82(1979)97,…)

IntroductionStructure of EW ： unspecified yetStandard Higgs mechanism Little Higgs model

(N.Arkani-Hamed, et al., JHEP 0208 (2002) 021 )

Higgsless model (C.Csaki, et al., PRD69 (2004) 055006)

Gauge-Higgs unification model (GHU)(N.Manton, NPB158 (1979)141, D.B.Fairlie, PLB82(1979)97,…)

In GHU, Higgs mass is protected byHigher dimensional gauge symmetry

spacetime: 5D flat ( )

gauge symmetry:

Simplest model (SU(3) model)

Z -Orbifold Parity

Orbifold conditions:

2

Higgs doublet

• Higgs doublet

• Higgs doublet

• (gauge-invariant) Wilson line phase

determined by quantum effect

Relations among mass scales

Warped spacetime Randall, Sundrum, PRL83 (1999) 3370

Relations among mass scales (warped case)(Hosotani, Mabe, PLB615 (2005) 257)

Problem of SU(3) model

• Wrong value of the Weinberg angle

• Rho parameter deviates from one.

Problem of SU(3) model

• Wrong value of the Weinberg angle

• Rho parameter deviates from one.

Problem of SU(3) model

• Wrong value of the Weinberg angle

• Rho parameter deviates from one.

SO(5)xU(1) modelB-L

Gauge fields:

Agashe,Contino,Pomarol, NPB719(2005)165

5D action

Symmetry breaking

Symmetry breaking

Higgs doublet

Symmetry breaking

Higgs doublet:

By using residual symemtry,

Wilson line phase:

Mass spectrum

W boson:

Z boson:

Weak gauge boson masses

Gauge couplings

Weinberg angle

Rho parameter

WWZ Coupling

SM value

WWH, ZZH couplings

Summary

SO(5)xU(1) model in warped spacetimeB-L

Future work

• Specify the fermionic sector.

• Include the quantum effects.

• Determine the value of dynamically.