An advance report on particle invariance in particle physics
  Since particle such as molecule, atom and nucleus are composite particle, it is important to recognize that physics must be invariant for both the composite particle and its constituent particles, this requirement is called particle invariance. But difficulties arise immediately because for fermion we use the Dirac equation, for boson we use the Klein-Gordon equation. Therefore, the particle invariance demands there is a general wave equation for describing particle motion regardless particle class. In this paper, three advances in this subject are reported: (1) momentum-wavefunction relation is a general relation shared by both fermion and boson, meets the requirement of the particle invaiance. As a test, the momentum-wavefunction relation was directly applied to hydrogen atom, and get the correct fine structure and spin effect for the electron. (2) the Dirac equation and Klein-Gordon equation can be derived out from the momentum-wavefunction relation when we abandon some higher order terms. (3) according to the momentum-wavefunction relation a path integral method was developed, differing from Feynman's path integral, it simplfies quantum computation. 
H. Y. Cui