1/4 Partial breaking of global supersymmetry and new superparticle actions Original Research Article

We construct the world-line superfield massive superparticle actions which preserve 1/4 portion of the underlying higher-dimensional supersymmetry. The rest of supersymmetry is spontaneously broken and realized by nonlinear transformations. We consider the cases of N=4→N=1 and N=8→N=2 partial breaking. In the first case we present the corresponding Green–Schwarz type target superspace action with one κ-supersymmetry. It is related to the superfield action via a field redefinition. In the second case we find out two possible models, one of which is a direct generalization of the N=4→N=1 case, while another is essentially different. For the first model we formulate Green–Schwarz type action with two κ-supersymmetries. We elaborate on the bosonic part of the superfield action for the second model and find that only in two special limits it takes the standard Nambu–Goto form. In the general case it is determined by a fourth-order algebraic equation. The characteristic common feature of these new superparticle models is that the algebras of their spontaneously broken supersymmetries are non-trivial truncations of the general extensions of N=1 and N=2 Poincaré D=4 superalgebras by tensorial central charges.