Difference between revisions of "Mattione GlueX Analysis Factories"

Revision as of 02:05, 12 August 2012

Summary

• In his/her plugin, a user specifies the reactions he/she wants to study (DReaction objects), then just asks JANA for the results (DTrackCombo objects).
  • Creates all possible track combinations for the desired reaction; user then cuts on the likelihood that those combinations represent the hypothesized reaction.

User Plugin DReaction Factory

• DReaction.h located in DANA libraries, DReaction_factory.h located in user plugin (along with a factory generator for it).
• Below shows how to set up DReaction for a Y(2175) analysis.

- //------------------
- // init

//------------------

jerror_t DReaction_factory::init(void)

{ // Setting the PERSISTANT prevents JANA from deleting // the objects every event so we only create them once. SetFactoryFlag(PERSISTANT);

DReaction* locReaction; DReactionStep* locReactionStep;

// Make as many DReaction objects as desired locReaction = new DReaction();

//g, p -> phi(2175), (p) locReactionStep = new DReactionStep(); locReactionStep->Set_InitialParticleID(Gamma); locReactionStep->Set_TargetParticleID(Proton); locReactionStep->Add_FinalParticleID(Unknown); //phi(2175) locReactionStep->Add_FinalParticleID(Proton); locReactionStep->Set_MissingParticleIndex(1); //proton missing locReaction->Add_ReactionStep(locReactionStep); dReactionStepPool.push_back(locReactionStep); //prevent memory leak

//phi(2175) -> pi+, pi-, phi locReactionStep = new DReactionStep(); locReactionStep->Set_InitialParticleID(Unknown); //phi(2175) locReactionStep->Set_TargetParticleID(Unknown); //no target for this step locReactionStep->Add_FinalParticleID(PiPlus); locReactionStep->Add_FinalParticleID(PiMinus); locReactionStep->Add_FinalParticleID(phiMeson); locReactionStep->Set_MissingParticleIndex(-1); //none missing locReaction->Add_ReactionStep(locReactionStep); dReactionStepPool.push_back(locReactionStep); //prevent memory leak

//phi -> K+, K- locReactionStep = new DReactionStep(); locReactionStep->Set_InitialParticleID(Unknown); //phi(2175) locReactionStep->Set_TargetParticleID(Unknown); //no target for this step locReactionStep->Add_FinalParticleID(KPlus); locReactionStep->Add_FinalParticleID(KMinus); locReactionStep->Set_MissingParticleIndex(-1); //none missing locReaction->Add_ReactionStep(locReactionStep); dReactionStepPool.push_back(locReactionStep); //prevent memory leak

_data.push_back(locReaction);

return NOERROR; }

DTrackCombo Factory

• (Would be) Located in DANA
  • Still finalizing class format, but looks similar to DReaction, except with full particles instead of just PIDs.
• Generate a DTrackCombo object for each possible combination of detected tracks (DBeamPhotons ignored).
  • For each q = +/-/0 particle in a given DReaction, all detected q = +/-/0 tracks are tested as to whether or not they are that particle (PID is NOT assumed).

DKinFitTrackCombo Factory

• (Would be) Located in DANA
  • Still finalizing class format, but looks similar to DReaction, except with full particles instead of just PIDs.
• Generate a DKinFitTrackCombo object for each possible combination of DTrackCombos and DBeamPhotons (ignore all DBeamPhotons "too far" from RF time).
  • Perform a single, full kinematic fit testing whether the DTrackCombo matches the DReaction: includes all mass, vertex, timing constraints (vertex & timing not yet implemented).

User Plugin DEventProcessor

extern "C" 
{
	void InitPlugin(JApplication *app)
	{
		InitJANAPlugin(app);
		app->AddProcessor(new DEventProcessor_Y2175());
		app->AddFactoryGenerator(new DFactoryGenerator_DReaction());
	}
} // "C"

jerror_t DEventProcessor_Y2175::evnt(JEventLoop *locEventLoop, int eventnumber)
{
	vector<const DKinFitTrackCombo*> locKinFitTrackCombos;
	locEventLoop->Get(locKinFitTrackCombos);

	//DO HISTS/CUTS/TUPLES HERE

	return NOERROR;
}

Cutting/Histogramming

• Coming Soon...

Tupling

• Haven't gotten this far yet...