1 The Topologies For a B decay to a single cascade charm D B IP lB lB lD lD ZVTOP vertex found furthest from IP contains the cleanest set of true B,D tracks For SLD VXD2: in jets with this vertex topology the fate of MC true primary tracks was 77% in the Primary 16% in the Secondary 3% in the Tertiary 4% left Isolated LCFI physics meeting 12/08/04

2 Highly boosted B kinematics: IP→B→D straight to ~1% (for Z 0 ) B,D vertex locations are not independent in 3D space ‘L/D’ construction based on this geometry

3 All non-primary vertices found must be n-prong with n ≥ 2 For IP→B→D decay chain can have 1-prong B or D decay Can consider n-prong ZVTOP vertex as a Seed vertex A track not directly associated with the Primary or Seed vertex, but with small T, is likely to come from B decay chain

4 L/D for non-Seed tracks passing T < 1mm Monte Carlo Track Origin D Decay IP B Decay VXD2 b-jets Cut at L/D > 0.3 to attach tracks from B decay chain to Seed NB, red curve above is the most sensitive to detector resolution