DCustomAction_p2gamma_hists.cc

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// $Id$
//
//    File: DCustomAction_p2gamma_hists.cc
// Created: Wed Jan 21 16:53:41 EST 2015
// Creator: jrsteven (on Linux ifarm1401 2.6.32-431.el6.x86_64 x86_64)
//

#include "DCustomAction_p2gamma_hists.h"

void DCustomAction_p2gamma_hists::Initialize(JEventLoop* locEventLoop)
{
   DApplication* dapp=dynamic_cast<DApplication*>(locEventLoop->GetJApplication());
   JCalibration *jcalib = dapp->GetJCalibration((locEventLoop->GetJEvent()).GetRunNumber());

   // Parameters for event selection to fill histograms
   endpoint_energy = 12.;
   map<string, double> photon_endpoint_energy;
   if(jcalib->Get("/PHOTON_BEAM/endpoint_energy", photon_endpoint_energy) == false) {
      endpoint_energy = photon_endpoint_energy["PHOTON_BEAM_ENDPOINT_ENERGY"];
   }
   endpoint_energy_bins = (int)(20*endpoint_energy);

   cohmin_energy = 0.;
   cohedge_energy = 12.;
   map<string, double> photon_beam_param;
   if(jcalib->Get("test/PHOTON_BEAM/coherent_energy", photon_beam_param) == false) {
      cohmin_energy = photon_beam_param["cohmin_energy"];
      cohedge_energy = photon_beam_param["cohedge_energy"];
   }

   dEdxCut = 2.2;
        minMM2Cut = -0.05;
        maxMM2Cut = 0.05;
        missingEnergyCut = 1.0;
        min2gMassCut = 0.10;
        max2gMassCut = 0.16;

   //CREATE THE HISTOGRAMS
   //Since we are creating histograms, the contents of gDirectory will be modified: must use JANA-wide ROOT lock
   japp->RootWriteLock(); //ACQUIRE ROOT LOCK!!
   {
      //Required: Create a folder in the ROOT output file that will contain all of the output ROOT objects (if any) for this action.
         //If another thread has already created the folder, it just changes to it. 
      CreateAndChangeTo_ActionDirectory();

      dEgamma = GetOrCreate_Histogram<TH1I>("Egamma", "TAGGER photon energy; E_{#gamma}", endpoint_energy_bins, 0., endpoint_energy);
      
      dMM2_M2g = GetOrCreate_Histogram<TH2I>("MM2_M2g", "MM^{2} off p #gamma#gamma vs M_{#gamma#gamma}; M_{#gamma#gamma}; MM^{2}", 500, 0.0, 1.0, 200, -1., 1.);
      dProton_dEdx_P = GetOrCreate_Histogram<TH2I>("Proton_dEdx_P","dE/dx vs p; p; dE/dx",200,0,2,500,0,5);
      dProton_P_Theta = GetOrCreate_Histogram<TH2I>("Proton_P_Theta","p vs #theta; #theta; p (GeV/c)",180,0,180,120,0,12);
      dProtonPhi_Egamma = GetOrCreate_Histogram<TH2I>("ProtonPhi_Egamma","#phi vs E_{#gamma}; E_{#gamma}; proton #phi",endpoint_energy_bins, 0., endpoint_energy,360,-180,180);
      dProtonPhi_Theta = GetOrCreate_Histogram<TH2I>("ProtonPhi_Theta","#phi vs #theta_{CM}; #pi^{0} #theta_{CM}; proton #phi",180,0,180,360,-180,180);
      dProtonPhi_t = GetOrCreate_Histogram<TH2I>("ProtonPhi_t","#psi vs |t|; |t|; proton #phi",1000,0.,5.,360,-180,180);

      dPi0Phi_Egamma = GetOrCreate_Histogram<TH2I>("Pi0Phi_Egamma","#phi vs E_{#gamma}; E_{#gamma}; #pi^{0} #phi",endpoint_energy_bins, 0., endpoint_energy,360,-180,180);
      dPi0Phi_Theta = GetOrCreate_Histogram<TH2I>("Pi0Phi_Theta","#phi vs #theta_{CM}; #pi^{0} #theta_{CM}; #pi^{0} #phi",180,0,180,360,-180,180);
      dPi0EgammaCorr = GetOrCreate_Histogram<TH2I>("Pi0EgammaCorr","E_{#gamma 1} vs E_{#gamma 2}; E_{#gamma 2}; E_{#gamma 1}",100,0.,5., 100.,0.,5.);

      dDeltaE_M2g = GetOrCreate_Histogram<TH2I>("dDeltaE_M2g", "#Delta E vs M_{#gamma#gamma}; M_{#gamma#gamma}; #Delta E (tagger - p#gamma#gamma)", 500, 0.0, 1.0, 200, -5., 5.);
      dPhi2g_PhiP = GetOrCreate_Histogram<TH2I>("Phi2g_PhiP", "#phi_{#gamma#gamma} vs. #phi_{p}; #phi_{p}; #phi_{#gamma#gamma}", 360, -180.0, 180.0, 360, -180., 180.);
      dDeltaPhi_M2g = GetOrCreate_Histogram<TH2I>("DeltaPhi_M2g", "#Delta#phi vs M_{#gamma#gamma}; M_{#gamma#gamma}; #Delta#phi", 500, 0.0, 1.0, 360, 0.0, 360.0);

      dEgamma_M2g_ProtonTag = GetOrCreate_Histogram<TH2I>("dEgamma_M2g_ProtonTag", "E_{#gamma} vs M_{#gamma#gamma}; M_{#gamma#gamma}; E_{#gamma}", 500, 0.0, 1.0, 240, 0., 6.);

      dMM2_M2g_CoplanarTag = GetOrCreate_Histogram<TH2I>("MM2_M2g_CoplanarTag", "MM^{2} off p #gamma#gamma vs M_{#gamma#gamma}: Coplanar Tag; M_{#gamma#gamma}; MM^{2}", 500, 0.0, 1.0, 200, -1., 1.);
                dDeltaE_M2g_CoplanarTag = GetOrCreate_Histogram<TH2I>("dDeltaE_M2g_CoplanarTag", "#Delta E vs M_{#gamma#gamma}: Coplanar Tag; M_{#gamma#gamma}; #Delta E (tagger - p#gamma#gamma)", 500, 0.0, 1.0, 200, -5., 5.);
      dMM2_DeltaE_CoplanarTag = GetOrCreate_Histogram<TH2I>("dMM2_DeltaE_CoplanarTag", "MM^{2} vs #Delta E: Coplanar Tag; #Delta E (tagger - p#gamma#gamma); MM^{2}", 200, -5., 5., 200, -1., 1.);

      dMM2_M2g_ProtonTag = GetOrCreate_Histogram<TH2I>("MM2_M2g_ProtonTag", "MM^{2} off p #gamma#gamma vs M_{#gamma#gamma}: Proton Tag; M_{#gamma#gamma}; MM^{2}", 500, 0.0, 1.0, 200, -1., 1.);
      dDeltaE_M2g_ProtonTag = GetOrCreate_Histogram<TH2I>("dDeltaE_M2g_ProtonTag", "#Delta E vs M_{#gamma#gamma}: Proton Tag; M_{#gamma#gamma}; #Delta E (tagger - p#gamma#gamma)", 500, 0.0, 1.0, 200, -5., 5.);
      dMM2_DeltaE_ProtonTag = GetOrCreate_Histogram<TH2I>("dMM2_DeltaE_ProtonTag", "MM^{2} vs #Delta E: Proton Tag; #Delta E (tagger - p#gamma#gamma); MM^{2}", 200, -5., 5., 200, -1., 1.);
      
      dMinEgamma_M2g = GetOrCreate_Histogram<TH2I>("MinEgamma_M2g", "Minimum E_{#gamma} vs M_{#gamma#gamma}; M_{#gamma#gamma}; Minimum E_{#gamma}", 500, 0., 1., 200, 0., 2.);

      //Return to the base directory
      ChangeTo_BaseDirectory();
   }
   japp->RootUnLock(); //RELEASE ROOT LOCK!!
}

bool DCustomAction_p2gamma_hists::Perform_Action(JEventLoop* locEventLoop, const DParticleCombo* locParticleCombo)
{
   const DParticleComboStep* locParticleComboStep = locParticleCombo->Get_ParticleComboStep(0);

        // get beam photon energy and final state particles
   auto locBeamPhoton = Get_UseKinFitResultsFlag() ? locParticleComboStep->Get_InitialParticle() : locParticleComboStep->Get_InitialParticle_Measured();
   auto locParticles = Get_UseKinFitResultsFlag() ? locParticleComboStep->Get_FinalParticles() : locParticleComboStep->Get_FinalParticles_Measured();
   double locBeamPhotonEnergy = locBeamPhoton->energy();
   
   // calculate missing mass
   DLorentzVector locMissingP4; 
   DLorentzVector locProtonP4Init(0,0,0,0.938);
   locMissingP4 += locProtonP4Init;
   locMissingP4 += locBeamPhoton->lorentzMomentum();
   DLorentzVector locSumInitP4 = locMissingP4;

   // reconstructed proton variables
   const DChargedTrack* locChargedTrack = static_cast<const DChargedTrack*>(locParticleComboStep->Get_FinalParticle_SourceObject(2));
   const DChargedTrackHypothesis* locChargedTrackHypothesis = locChargedTrack->Get_Hypothesis(Proton);
   auto locTrackTimeBased = locChargedTrackHypothesis->Get_TrackTimeBased();
   double dEdx = locTrackTimeBased->dEdx()*1e6; // convert to keV
   DLorentzVector locProtonP4 = locChargedTrackHypothesis->lorentzMomentum();
   
   // calculate missing mass
   DLorentzVector loc2g_P4;
   set<pair<const JObject*, Particle_t> > locSourceObjects;
   for(size_t loc_i = 0; loc_i < 3; ++loc_i) {
      locMissingP4 -= locParticles[loc_i]->lorentzMomentum();
      
      if(locParticles[loc_i]->PID() == Gamma) {
         locSourceObjects.insert(pair<const JObject*, Particle_t>(locParticleComboStep->Get_FinalParticle_SourceObject(loc_i), locParticles[loc_i]->PID()));
         loc2g_P4 += locParticles[loc_i]->lorentzMomentum();
      }
   }

   bool fillHist = true;
   if(dPreviousSourceObjects.find(locSourceObjects) != dPreviousSourceObjects.end())
      fillHist = false; //dupe: already histed!
   dPreviousSourceObjects.insert(locSourceObjects);

   DLorentzVector locGamma1P4 = locParticleCombo->Get_ParticleComboStep(0)->Get_FinalParticle_Measured(0)->lorentzMomentum();
   DLorentzVector locGamma2P4 = locParticleCombo->Get_ParticleComboStep(0)->Get_FinalParticle_Measured(1)->lorentzMomentum();
   double locMinEgamma = min(locGamma1P4.E(), locGamma2P4.E());

   // production kinematics
   TVector3 locBoostVector = -1.*locSumInitP4.BoostVector();
   TLorentzVector locGamma_P4CMFrame = locBeamPhoton->lorentzMomentum();
   TLorentzVector locPi0_P4CMFrame = loc2g_P4;
   locGamma_P4CMFrame.Boost(locBoostVector);
   locPi0_P4CMFrame.Boost(locBoostVector);
   double locThetaCM = locGamma_P4CMFrame.Vect().Angle(locPi0_P4CMFrame.Vect());
   TLorentzVector locDelta = (locProtonP4 - locProtonP4Init);
   double t = locDelta.M2();
   
   //FILL HISTOGRAMS
   //Since we are filling histograms local to this action, it will not interfere with other ROOT operations: can use action-wide ROOT lock
   //Note, the mutex is unique to this DReaction + action_string combo: actions of same class with different hists will have a different mutex
   Lock_Action(); //ACQUIRE ROOT LOCK!!
   {
      // Fill histograms here
      dEgamma->Fill(locBeamPhotonEnergy);
      
      if(fillHist)
         dMinEgamma_M2g->Fill(loc2g_P4.M(), locMinEgamma);

      dMM2_M2g->Fill(loc2g_P4.M(), locMissingP4.M2());
      dDeltaE_M2g->Fill(loc2g_P4.M(),locMissingP4.E());

      double locDeltaPhi = (locProtonP4.Phi() - loc2g_P4.Phi())*180./TMath::Pi();
      if(locDeltaPhi > 360.) locDeltaPhi -= 360.;
      if(locDeltaPhi < 0.) locDeltaPhi += 360.;
      dPhi2g_PhiP->Fill(locProtonP4.Phi()*180./TMath::Pi(), loc2g_P4.Phi()*180./TMath::Pi());
      dDeltaPhi_M2g->Fill(loc2g_P4.M(), locDeltaPhi);
      
      // require proton and pi0 are back-to-back
      if(locDeltaPhi > 175. && locDeltaPhi < 185.) {
         
         dMM2_M2g_CoplanarTag->Fill(loc2g_P4.M(), locMissingP4.M2());
         dDeltaE_M2g_CoplanarTag->Fill(loc2g_P4.M(), locMissingP4.E());
         if(loc2g_P4.M() > min2gMassCut && loc2g_P4.M() < max2gMassCut)
            dMM2_DeltaE_CoplanarTag->Fill(locMissingP4.E(), locMissingP4.M2());
         
         // tag proton with dE/dx
         if(dEdx > dEdxCut) {
            dMM2_M2g_ProtonTag->Fill(loc2g_P4.M(), locMissingP4.M2());
            dDeltaE_M2g_ProtonTag->Fill(loc2g_P4.M(), locMissingP4.E());
            if(loc2g_P4.M() > min2gMassCut && loc2g_P4.M() < max2gMassCut)
               dMM2_DeltaE_ProtonTag->Fill(locMissingP4.E(), locMissingP4.M2());
            
            // di-photon invariant mass for exclusive g+p -> p + 2g
            if(locMissingP4.M2() > minMM2Cut && locMissingP4.M2() < maxMM2Cut && fabs(locMissingP4.E()) < missingEnergyCut) {
               dEgamma_M2g_ProtonTag->Fill(loc2g_P4.M(),locBeamPhotonEnergy);
            }
         }
         
         // for pi0 candidates require recoil proton
         if(loc2g_P4.M() > min2gMassCut && loc2g_P4.M() < max2gMassCut && locMissingP4.M2() > minMM2Cut && locMissingP4.M2() < maxMM2Cut && fabs(locMissingP4.E()) < missingEnergyCut) {
            dProton_dEdx_P->Fill(locProtonP4.Vect().Mag(), dEdx);
            dProton_P_Theta->Fill(locProtonP4.Vect().Theta()*180/TMath::Pi(), locProtonP4.Vect().Mag());       
            dProtonPhi_Egamma->Fill(locBeamPhotonEnergy, locProtonP4.Phi()*180/TMath::Pi());
            dPi0Phi_Egamma->Fill(locBeamPhotonEnergy, loc2g_P4.Phi()*180/TMath::Pi());
            
            if(locBeamPhotonEnergy > cohmin_energy && locBeamPhotonEnergy < cohedge_energy){ 
               dProtonPhi_Theta->Fill(locThetaCM*180/TMath::Pi(), locProtonP4.Phi()*180/TMath::Pi());
               dProtonPhi_t->Fill(fabs(t), locProtonP4.Phi()*180/TMath::Pi());
               dPi0Phi_Theta->Fill(locThetaCM*180/TMath::Pi(), loc2g_P4.Phi()*180/TMath::Pi());
               dPi0EgammaCorr->Fill(locParticles[0]->energy(),locParticles[1]->energy());
            }
         }
      }
   }
   Unlock_Action(); //RELEASE ROOT LOCK!!

   return true; //return false if you want to use this action to apply a cut (and it fails the cut!)
}