Merge pull request #193 from JeffersonLab/iss192

Add momentum info to the MC Tracker Hit
JeffersonLab · Apr 22, 2024 · fbf36b0 · fbf36b0
2 parents 3b03733 + d67e8d4
commit fbf36b0
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Showing 3 changed files with 39 additions and 15 deletions.
diff --git a/event/include/MCTrackerHit.h b/event/include/MCTrackerHit.h
@@ -37,10 +37,13 @@ class MCTrackerHit : public TObject {
          *
          * @param position The hit position.
          */
-        void setPosition(const double* position, bool rotate = false);
-
-        /** @return The hit position. */
-        std::vector<double> getPosition() const { return {x_, y_, z_}; };
+  void setPosition(const double* position, bool rotate = false);
+
+  /** @return The hit position. */
+  std::vector<double> getPosition() const { return {x_, y_, z_}; };
+
+  void setMomentum(const float* momentum, bool rotate = false);
+  std::vector<float> getMomentum() const { return {px_, py_, pz_}; };
 
         /** @return the global X coordinate of the hit */
         double getGlobalX() const {return x_;}
@@ -88,7 +91,8 @@ class MCTrackerHit : public TObject {
         //** @return the pdg id of particle that made the hit */
         int getPDG() const {return pdg_;};
 
-        ClassDef(MCTrackerHit, 1);	
+
+  ClassDef(MCTrackerHit, 1);	
 
     private:
 
@@ -101,6 +105,11 @@ class MCTrackerHit : public TObject {
         /** The x position of the hit. */
         double z_{-999};
 
+         /** The truth momentum of the hit. Only MC */
+        float px_{-999};
+        float py_{-999};
+        float pz_{-999};
+
         /** The hit time. */
         double time_{-999};
 

diff --git a/event/src/MCTrackerHit.cxx b/event/src/MCTrackerHit.cxx
@@ -20,6 +20,25 @@ void MCTrackerHit::Clear(Option_t* /* options */) {
     TObject::Clear(); 
 }
 
+void MCTrackerHit::setMomentum(const float* momentum, bool rotate) {
+
+    //svt angle: it's already with minus sign.
+    float svtAngle = 30.5e-3;
+    //Rotate the the input position automatically to match with the SVT tracker system
+    if (rotate)
+    {
+        //x_ = position[1];
+        py_ = momentum[2];
+        pz_ = momentum[1] * sin(svtAngle) + momentum[0]*cos(svtAngle);
+        px_ = momentum[1] * cos(svtAngle) - momentum[0]*sin(svtAngle);
+    }
+    else {
+        px_ = momentum[0]; 
+        py_ = momentum[1];
+        pz_ = momentum[2];
+    }
+}
+
 void MCTrackerHit::setPosition(const double* position, bool rotate) {
 
     //svt angle: it's already with minus sign.

diff --git a/processors/src/MCTrackerHitProcessor.cxx b/processors/src/MCTrackerHitProcessor.cxx
@@ -71,16 +71,12 @@ bool MCTrackerHitProcessor::process(IEvent* ievent) {
         mc_tracker_hit->setLayer(decoder["layer"]);
         mc_tracker_hit->setModule(decoder["module"]);
 
-        // Set the position of the hit
-        double hitPos[3];
-        hitPos[0] = lcio_mcTracker_hit->getPosition()[0];
-        hitPos[1] = lcio_mcTracker_hit->getPosition()[1];
-        hitPos[2] = lcio_mcTracker_hit->getPosition()[2];
-        mc_tracker_hit->setPosition(hitPos);
-
-        // Set the energy deposit of the hit
+	mc_tracker_hit->setPosition(lcio_mcTracker_hit->getPosition());
+	mc_tracker_hit->setMomentum(lcio_mcTracker_hit->getMomentum());
+
+	// Set the energy deposit of the hit
         mc_tracker_hit->setEdep(lcio_mcTracker_hit->getEDep());
-
+	
         // Set the pdg of particle generating the hit
         if(lcio_mcTracker_hit->getMCParticle()) 
             mc_tracker_hit->setPDG(lcio_mcTracker_hit->getMCParticle()->getPDG());
@@ -90,7 +86,7 @@ bool MCTrackerHitProcessor::process(IEvent* ievent) {
 
         //Push hit onto vector
         trackerhits_.push_back(mc_tracker_hit);
-
+	
     }
 
     return true;