Realistic Supersymmetric SU(6)

Abstract

We present an example of SUSY SU(6) GUT, which predicts an excellent value for ${\text{al}}_s(M_Z)(\simeq 0.119)$, in comparison with the value ${\text{al}}_s^0(M_Z)\simeq 0.126$ of minimal SUSY SU(5). A crucial role is played by the vectorlike multiplets from the matter sector, whose masses lie below the GUT scale. For a realistic pattern of fermion masses, the adjoint scalar of SU(6) has VEV along the $SU(4)\times SU(2)\times U(1)$ direction. This also offers a natural resolution of the doublet-triplet (DT) splitting through the pseudo Goldstone Boson mechanism.

Comments: LaTex, one eps figure