Covariant quantization of d=4 Brink-Schwarz superparticle using Lorentz harmonics

The first and second covariant quantization of a free d=4 massless superparticle with pure gauge auxiliary spinor Lorentz harmonics involved have been carried out. It is shown that general solution of massless condition is a sum of two independent chiral superfields, each of them corresponds to finite superspin. Translational covariant correspondence between harmonic and massless superfields, generally biective, has been built. By means of calculation of a permutation function, it is shown, that in considering approach only harmonic superfields with right connection between spin and statistics and negative integer index of homogeniouty satisfy microcausality condition. Reducibility of occurring harmonic superfields in integer points is stressed. Index spinor technique is applied to describe infinite-component massless fields with finite spin. Equations of motion for these fields have been obtained. Weinberg theorem on connection between helicity of massless particles and type of a nongauge field describing them is generalized for those fields. 39 refs