New Signatures for a Light Stop at LEP2 in SUSY Models with   Spontaneously Broken R-Parity
  In a class of supersymmetric models with R-parity breaking the lightest stop can have new decay modes into third generation fermions, $\tilde{t}_1 \rightarrow b + \tau$. We show that this decay may be dominant or at least comparable to the ordinary R-parity conserving mode $\tilde{t}_1 \rightarrow c + \tilde{\chi}_1^0$, where $\tilde{\chi}_1^0$ denotes the lightest neutralino. The new R-parity violating decay mode could provide new signatures for stop production at LEP. 
A. Bartl, W. Porod, M. A. Garcia-Jareno, M. B. Magro, J. W. F. Valle   and W. Majerotto