Study of the doubly and singly Cabibbo suppressed decays D+ --> K+ pi+   pi- and Ds+ --> K+ pi+ pi-
  Using data collected by the high energy photoproduction experiment FOCUS at Fermilab we study the doubly and singly Cabibbo suppressed decays D+ and Ds+ --> K+ pi+ pi-. Branching ratios and Dalitz plot analyses are performed. 
FOCUS collaboration