Horizontal symmetry in Higgs sector of GUT withU(1)Asymmetry

Nobuhiro Maekawa, Toshifumi Yamashita
2004 Journal of High Energy Physics  
In a series of papers, we pointed out that an anomalous U(1)_A gauge symmetry naturally solves various problems in grand unified theories (GUTs) and that a horizontal gauge symmetry, SU(2)_H or SU(3)_H, not only realizes the unification of three generation quarks and leptons in fewer multiplets but also solves the supersymmetric flavor problem. In this paper, we examine the possibility that the Higgs sectors of the GUT symmetry and of the horizontal symmetry are unified, that is, there are some
more » ... Higgs fields whose vacuum expectation values (VEVs) break both the GUT gauge symmetry and the horizontal symmetry at the same time. Although the scale of the VEVs become too large to suppress the flavor changing neutral current processes sufficiently, the unification is possible. In addition, for the SU(3)_H models, the SU(3)_H gauge anomaly is cancelled in the unified models without introducing additional fields in contrast with the previous models in which the Higgs sectors are not unified.
doi:10.1088/1126-6708/2004/07/009 fatcat:lhy2wpnppjdo7gecjxbjhrx5ki