A study of Bs0 Meson Oscillations using Ds-Lepton  Events                      
  
A sample of Bs0 decays is obtained using Ds-lepton+ combinations, where        
the Ds is fully reconstructed in the phi pi-, K*0 K- and K- Ks decay channels  
or partially reconstructed in the phi lepton- X decay mode. These events are   
used to study Bs0 oscillations. The flavour (b or b-bar) at decay is           
determined from the lepton charge while the flavour at production is           
determined from four indicators: the momentum weighted jet charges for the     
candidate jet and the opposite jet and, where available, the charges of a      
prompt lepton in the opposite hemisphere and of a fragmentation kaon.          
  
 Parallel session :7                   
 Plenary  session :3