SUPERPARTICLES IN D-GREATER-THAN-11

Actions for two-superparticle system in (10,2) dimensions and three-su perparticle systems in (11,3) dimensions are constructed. These action s have worldline bosonic and fermionic local symmetries, and target sp ace global supersymmety generalizing the reparametrization, kappa-symm etry and Poincare supersymmetry of the usual superparticle. With the s econd particle, or the second and third particles on-shell, they descr ibe a superparticle propagating in the background of a second superpar ticle in (10,2) dimensions, or two other superparticles in (11,3) dime nsions. Symmetries of the action are shown to exist in presence of sup er Yang-Mills background as well. (C) 1997 Published by Elsevier Scien ce B.V.