Top--bottom mass hierarchy, s - µ puzzle and gauge coupling unification with split multiplets
School of Physics, Korea Institute for Advanced Study, Cheongryangri-dong, Dongdaemun-ku, Seoul 135-012, Korea
2 School of Physics and Center for Theoretical Physics, Seoul National University, Seoul 151-747, Korea
Revised: 22 January 2002
Published online: 5 April 2002
Supersymmetric 5D SU(5) grand unification is considered. SU(5) is broken down to GSM = SU(3) × SU(2) × U(1) by the Z2 × Z2' assignment of the bulk field(s). The matter fields are located at the fixed point(s). In the bulk, a Higgs multiplet ͞5H (containing the bottom doublet H1) and the SU(5) gauge multiplet are located. At one fixed point, H2 (the top doublet) and the standard model matter multiplets are presented. Because of the difference of the locations of H1 and H2, one can obtain a hierarchy between top and bottom Yukawa couplings. We also present a possible way to understand the s–µ mass puzzle in this framework of the split multiplet.
© Società Italiana di Fisica, Springer-Verlag, 2002