Partial spontaneous breaking of two-dimensional supersymmetry

We construct low-energy Goldstone superfield actions describing various patterns of the partial spontaneous breakdown of two-dimensional N = (1, 1), N = (2, 0) and N = (2, 2) supersymmetries, with the main focus on the last case. These nonlinear actions admit a representation in the superspace of the unbroken supersymmetry as well as in a superspace of the full supersymmetry. The natural setup for implementing the partial breaking in a self-consistent way is provided by the appropriate central extensions of D = 2 supersymmetries, with the central charges generating shift symmetries on the Goldstone superfields, The Goldstone superfield actions can be interpreted as manifestly worldsheet supersymmetric actions in the static gauge of some superstrings and D1-branes in D = 3 and D = 4 Minkowski spaces. As an essentially new example, we elaborate on the action representing the 1/4 partial breaking pattern N = (2, 2) --> N = (1, 0). (C) 2001 Elsevier Science B.V. All rights reserved.