Spectrum and couplings of SO(5) x U(1) gauge-Higgs unification model in warped spacetime Yutaka Sakamura (Osaka Univ.) with Yutaka Hosotani (Osaka Univ.) Phys.Lett.B645 (2007) 442 March 2, B-L

Introduction Structure of EW ： unspecified yet Standard Higgs mechanism Little Higgs model (N.Arkani-Hamed, et al., JHEP 0208 (2002) 021 ) Higgsless model (C.Csaki, et al., PRD69 (2004) ) Gauge-Higgs unification model (GHU) (N.Manton, NPB158 (1979)141, D.B.Fairlie, PLB82(1979)97,…)

Introduction Structure of EW ： unspecified yet Standard Higgs mechanism Little Higgs model (N.Arkani-Hamed, et al., JHEP 0208 (2002) 021 ) Higgsless model (C.Csaki, et al., PRD69 (2004) ) Gauge-Higgs unification model (GHU) (N.Manton, NPB158 (1979)141, D.B.Fairlie, PLB82(1979)97,…) In GHU, Higgs mass is protected by Higher dimensional gauge symmetry

spacetime: 5D flat ( ) gauge symmetry: Simplest model (SU(3) model)

Z -Orbifold Parity Orbifold conditions: 2

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) x U(1) model B-L Gauge fields: Agashe,Contino,Pomarol, NPB719(2005)165

5D action

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) x U(1) model in warped spacetime B-L

Future work Specify the fermionic sector. Include the quantum effects. Determine the value of dynamically.