Data Structure

The event data structure is a tree of information about a particular event. Event producers (like [wiki:UserGuideGsim Gsim]) create an instance of the the data structure for each event, and processors can then operate on this structure, transforming it as desired.

A point of clarification: Unfortunately, “event” is an ambiguous term. There is what you might call a ‘’physics event,’’ which represents a single interaction, like nu-bar + p -> e+ + n. The simulated detector, however, will probably turn that into at least two ‘’detector events.’’ Unless specified, assume “event” means “physics event.”

Data Structure Definition

Brackets in the name indicate that item is an array of the listed type. The brackets are not valid ROOT syntax, so you should drop them when plotting, as in:

T->Draw("mc.particle.x");

General Information

name type description
lastProcResult int Result code of last processor, OK = 0, FAIL=1, ABORT=2
ratversion int Version of RAT which produced this event, ver 0.1 = 100, ver 1.2 = 1200, and so on

Monte Carlo Information

name type description
mc MC Contains all Monte Carlo information
mc.runID int Run number
mc.eventID int Event number
mc.UT double Time of this event (units, origin?)

Monte Carlo Particles

Monte Carlo PMT Information

Monte Carlo Track Information

Detected Event Information

Event Reconstruction