Changes in modules/ParticlePropagator.cc [187fc41:764f12a0] in git

File:

• modules/ParticlePropagator.cc (modified) (10 diffs)

modules/ParticlePropagator.cc

@@ -66 +66 @@
 {
 }
-
 
 //------------------------------------------------------------------------------
@@ -92 +91 @@
   fItInputArray = fInputArray->MakeIterator();
 
-  // import beamspot
- 
-  fBeamSpotInputArray = ImportArray(GetString("BeamSpotInputArray", "BeamSpotFilter/beamSpotParticle"));
-
   // create output arrays
 
@@ -116 +111 @@
 {
   Candidate *candidate, *mother;
-  TLorentzVector candidatePosition, candidateMomentum, beamSpotPosition;
+  TLorentzVector candidatePosition, candidateMomentum;
   Double_t px, py, pz, pt, pt2, e, q;
   Double_t x, y, z, t, r, phi;
@@ -125 +120 @@
   Double_t tmp, discr, discr2;
   Double_t delta, gammam, omega, asinrho;
-  Double_t rcu, rc2, xd, yd, zd;
-  Double_t l, d0, dz, p, ctgTheta, phip, etap, alpha;
-  Double_t bsx, bsy, bsz;
-         
+  Double_t rcu, rc2, dxy, xd, yd, zd;
+
   const Double_t c_light = 2.99792458E8;
- 
-  if (!fBeamSpotInputArray->GetSize () || !fBeamSpotInputArray->At(0)) 
-    beamSpotPosition.SetXYZT(0.0, 0.0, 0.0, 0.0);
-  else
-  {
-    Candidate &beamSpotCandidate = *((Candidate *) fBeamSpotInputArray->At(0));
-    beamSpotPosition = beamSpotCandidate.Position;
-  }
- 
+
   fItInputArray->Reset();
   while((candidate = static_cast<Candidate*>(fItInputArray->Next())))
@@ -147 +132 @@
     y = candidatePosition.Y()*1.0E-3;
     z = candidatePosition.Z()*1.0E-3;
-    
-    bsx = beamSpotPosition.X()*1.0E-3;
-    bsy = beamSpotPosition.Y()*1.0E-3;
-    bsz = beamSpotPosition.Z()*1.0E-3;
-   
     q = candidate->Charge;
 
@@ -201 +181 @@
       y_t = y + py*t;
       z_t = z + pz*t;
-      
-      l = TMath::Sqrt( (x_t - x)*(x_t - x) + (y_t - y)*(y_t - y) + (z_t - z)*(z_t - z));
 
       mother = candidate;
@@ -208 +186 @@
 
       candidate->Position.SetXYZT(x_t*1.0E3, y_t*1.0E3, z_t*1.0E3, candidatePosition.T() + t*e*1.0E3);
-      candidate->L = l*1.0E3;
-   
+
       candidate->Momentum = candidateMomentum;
       candidate->AddCandidate(mother);
@@ -261 +238 @@
       yd = (rc2 > 0.0) ? yd / rc2 : -999;
       zd = z + (TMath::Sqrt(xd*xd + yd*yd) - TMath::Sqrt(x*x + y*y))*pz/pt;
-      
-      // use perigee momentum rather than original particle
-      // momentum, since the orignal particle momentum isn't known 
-      
-      px = TMath::Sign(1.0,r) * pt * (-y_c / r_c);
-      py = TMath::Sign(1.0,r) * pt * (x_c / r_c);
-      etap = candidateMomentum.Eta();
-      phip = TMath::ATan2(py, px);
-       
-      candidateMomentum.SetPtEtaPhiE(pt, etap, phip, candidateMomentum.E());
-      
-      // calculate additional track parameters (correct for beamspot position)
-       
-      d0        = (  (x - bsx) * py - (y - bsy) * px) / pt;
-      dz        = z - ((x - bsx) * px + (py - bsy) * py) / pt * (pz / pt);
-      p         = candidateMomentum.P();
-      ctgTheta  = 1.0 / TMath::Tan (candidateMomentum.Theta ());
-         
+
+      // calculate impact paramater
+      dxy = (xd*py - yd*px)/pt;
+
       // 3. time evaluation t = TMath::Min(t_r, t_z)
       //    t_r : time to exit from the sides
@@ -324 +287 @@
       r_t = TMath::Hypot(x_t, y_t);
 
-      
-      // compute path length for an helix
-      
-      alpha = pz*1.0E9 / c_light / gammam;
-      l = t * TMath::Sqrt(alpha*alpha + r*r*omega*omega);
-          
       if(r_t > 0.0)
       {
@@ -338 +295 @@
 
         candidate->Momentum = candidateMomentum;
-        
-        candidate->L =  l*1.0E3;
-        candidate->D0 = d0*1.0E3;
-        candidate->DZ = dz*1.0E3;
-        candidate->P = p;
-        candidate->PT = pt;
-        candidate->CtgTheta = ctgTheta;
-        candidate->Phi = phi;
-
-        candidate->Xd = xd*1.0E3;
+        candidate->Dxy = dxy*1.0E3;
+        candidate->Xd = xd*1.0E3;
         candidate->Yd = yd*1.0E3;
         candidate->Zd = zd*1.0E3;