Stability of Proton and Maximally Symmetric Minimal Unification Model   for Basic Forces and Building Blocks of Matter
  With the hypothesis that all independent degrees of freedom of basic building blocks should be treated equally on the same footing and correlated by a possible maximal symmetry, we arrive at an 4-dimensional space-time unification model. In this model the basic building blocks are Majorana fermions in the spinor representation of 14-dimensional quantum space-time with a gauge symmetry $G = SO(1,3)\times SU(32)\times U(1)_A \times SU(3)_F$. The model leads to new physics including mirror particles of the standard model. It enables us to issue some fundamental questions that include: why our living space-time is 4-dimensional, why parity is not conserved in our world, how is the stability of proton, what is the origin of CP violation and what can be the dark matter. 
Yue-Liang Wu