Study of the D0→K+K−π+π− decay

Abstract Using data from the FOCUS (E831) experiment at Fermilab, we present a new measurement for the Cabibbo-suppressed decay mode D 0 → K + K − π + π − . We measure: Γ ( D 0 → K + K − π + π − ) / Γ ( D 0 → K − π − π + π + ) = 0.0295 ± 0.0011 ± 0.0008 . An amplitude analysis has been performed in order to determine the resonant substructure of this decay mode. The dominant components are the decays D 0 → K 1 ( 1270 ) + K − , D 0 → K 1 ( 1400 ) + K − and D 0 → ρ ( 770 ) 0 ϕ ( 1020 ) .