A non-Abelian Chern-Simons term for non-BPS D-branes
  We propose a Chern-Simons term for N coinciding non-BPS D-branes. Demanding full U(N) invariance and compatibility with T-duality, it is shown that it is necessary to introduce new interaction terms, through which the non-BPS D-branes couple to all p-form RR fields. 
Bert Janssen, Patrick Meessen