Mattione GlueX Analysis Factories
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Contents
Summary
- In his/her plugin, a user specifies the reactions he/she wants to study (DReaction objects), then just asks JANA for the results (DKinFitTrackCombo 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.
jerror_t DReaction_factory::init(void) { // Make as many DReaction objects as desired DReaction* locReaction = new DReaction(); { //g, p -> Y(2175), (p) DReactionStep locReactionStep; locReactionStep.dInitialParticleID = Gamma; locReactionStep.dTargetParticleID = Proton; locReactionStep.dFinalParticleIDs.push_back(Unknown); //Y(2175) locReactionStep.dFinalParticleIDs.push_back(Proton); locReactionStep.dMissingParticleIndex = 1; //proton missing locReactionStep.dDetachedVertexFlag = false; locReaction->dReactionSteps.push_back(locReactionStep); } { //Y(2175) -> pi+, pi-, phi DReactionStep locReactionStep; locReactionStep.dInitialParticleID = Unknown; //Y(2175) locReactionStep.dTargetParticleID = Unknown; //no target locReactionStep.dFinalParticleIDs.push_back(PiPlus); locReactionStep.dFinalParticleIDs.push_back(PiMinus); locReactionStep.dFinalParticleIDs.push_back(phiMeson); locReactionStep.dMissingParticleIndex = -1; //none missing locReactionStep.dDetachedVertexFlag = false; locReaction->dReactionSteps.push_back(locReactionStep); } { //phi -> K+, K- DReactionStep locReactionStep; locReactionStep.dInitialParticleID = phiMeson; locReactionStep.dTargetParticleID = Unknown; //no target locReactionStep.dFinalParticleIDs.push_back(KPlus); locReactionStep.dFinalParticleIDs.push_back(KMinus); locReactionStep.dMissingParticleIndex = -1; //none missing locReactionStep.dDetachedVertexFlag = false; //I'm not sure locReaction->dReactionSteps.push_back(locReactionStep); } _data.push_back(locReaction); }
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...