A LOCALLY SUPERSYMMETRIC ACTION FOR THE SCALAR PARTICLE

We construct a locally supersymmetric action for the scalar particle, and study its relation with the usual reparametrization invariant acti on. The mechanisms at work are similar to those employed in the embedd ing of the bosonic string into the fermionic one, originally due to Be rkovits and Vafa in their search for a universal string. The simpler a lgebraic structure present in the particle case provides us with a gui de on how to prove in a simple way, without the need of fixing the sup erconformal gauge, that the supersymmetric formulation of the bosonic string is equivalent to the usual one, where reparametrization invaria nce is the only worldsheet gauge symmetry.