Geometrical formulation for the Siegel superparticle}

In the superspace $z^M = (x^\mu,\theta_R,\theta_L)$ the global symmetries for $d$ = 10 superparticle model with kinetic terms both for Bose and Fermi variables are shown to form a superalgebra, which includes the Poincar\'e superalgebra as a subalgebra. The subalgebra is realized in the space of variables of the theory by a nonstandard way. The local version of this model with off-shell closed Lagrangian algebra of gauge symmetries and off-shell global supersymmetry is presented. It is shown that the resulting model is dynamically equivalent to the Siegel superparticle.