Lorentz-Covariant Quantization of Massless Non-Abelian Gauge Fields in   The Hamiltonian Path-Integral Formalism
  The Lorentz-covariant quantization performed in the Hamiltonian path-integral formalism for massless non-Abelian gauge fields has been achieved. In this quantization, the Lorentz condition, as a constraint, must be introduced initially and incorporated into the Yang-Mills Lagrangian by the Lagrange undetermined multiplier method. In this way, it is found that all Lorentz components of a vector potential have thier corresponding conjugate canonical variables. This fact allows us to define Lorentz-invariant poisson brackets and carry out the quantization in a Lorent-covariant manner. Key words: Non-Abelian gauge field, quantization, Hamiltonian path-integral formalism, Lorentz covariance. 
Jun-Chen Su