First step… “taking as input events from somewhere…”

StHbtManager

StHbtMaker

Maker chain

StHbtEventReader (Base class)

virtual StHbtEvent* ReturnHbtEvent()

StHbtBinaryReader (mDST)

StStandardHbtEventReader

ReturnHbtEvent{

…

StHbtEvent* hbtEvent = new StHbtEvent;

int mult = rEvent->trackNodes().size();

hbtEvent->SetNumberOfTracks(mult);

if ( rEvent->numberOfPrimaryVertices() != 1) {

delete hbtEvent;

return 0;

}

StHbtThreeVector vp = rEvent->primaryVertex()->position();

hbtEvent->SetPrimVertPos(vp);

…

return hbtEvent;

StHbtMcEventReader

…

HbtManager requests/gets an

StHbtEvent from “unknown” source

StHbtEvent (with its StHbtTrack’s and StHbtV0’s)

is HBT’s clean generic interface to the data

note typedef’ing

for isolation

StEvent object