  The Standard Model group and matter spectrum is obtained in vacua of
F-theory, without resorting to an intermediate unification group. The group
SU(3) x SU(2) x U(1)_Y is the commutant to SU(5)_t \times U(1)_Y structure
group of a Higgs bundle in E_8 and is geometrically realized as a deformation
of I_5 singularity. Lying along the unification groups of E_n, our vacua
naturally inherit their unification structure. By modding SU(5)_t out by Z_4
monodromy group, we can distinguish Higgses from lepton doublets by matter
parity. Turning on universal G-flux on this part, the spectrum contains three
generations of quarks and leptons, as well as vectorlike pairs of electroweak
and colored Higgses. Minimal Yukawa couplings is obtained at the renormalizable
level.

High Energy Physics - Theory