The local, covariant, continuous, anticommuting and nilpotent
Becchi-Rouet-Stora-Tyutin (BRST) and anti-BRST symmetry transformations for all
the fields of a (0 + 1)-dimensional spinning relativistic particle are obtained
in the framework of augmented superfield approach to BRST formalism. The
trajectory of this super-particle is parametrized by a monotonically increasing
parameter \tau that is embedded in a D-dimensional flat Minkowski spacetime
manifold. This physically useful one-dimensional system is considered on a
three (1 + 2)-dimensional supermanifold which is parametrized by an even
element \tau and a couple of odd elements \theta and \bar\theta of the
Grassmann algebra. Two anticommuting sets of (anti-)BRST symmetry
transformations, corresponding to the underlying (super)gauge symmetries for
the above system, are derived in the framework of augmented superfield
formulation where (i) the horizontality condition, and (ii) the invariance of
conserved quantities on the supermanifold, play decisive roles. Geometrical
interpretations for the above nilpotent symmetries (and their generators) are
provided.Comment: LaTeX file, 21 pages, a notation clarified, a footnote added and
related statements corrected in Introduction, version to appear in EPJ
