Supersymmetric Standard Model: Solving the gauge hierarchy problem e Gauge coupling unification Radiatively electroweak symmetry breakin arge top quark mass e Natural dark matter candidates Neutralino, sneutrino, gravitino Electroweak baryogenesis Electroweak precision: R parity
6
Gauge Coupling Unification 60 50 40 SU(2) 30 20F 10 sU(3) 4681012141618 Log(Q/GeV
Gauge Coupling Unification 7
Problems in the mssm u problem uhud Little hierarchy problem Fine-tuning for the lightest CP even Higgs mass e CP violation and eDms FCNC Dimension-5 proton decays
8
The Grand Unified Theories: SU(5), and SO(10), etc Unification of the gauge interactions, and unifications of the SM fermions Charge quantization Gauge coupling unification in the MSSM, and Yukawa unification 犹t=b=y Radiative electroweak symmetry breaking due to the large top quark Yukawa coupling e Weak mixing angle at weak scale Mz Neutrino masses and mixings by seesaw mechanism
Problems Gauge symmetry breaking Doublet-triplet splitting problem Higgs particles do not form complete GUT multiplet at low energy ● Proton decay problen Fermion mass problem GUT relation me/mu=md/ms