MultipleScatteringGeometry.cc

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#include "MultipleScatteringGeometry.h"
#include "TrackingTools/DetLayers/interface/BarrelDetLayer.h"
#include "TrackingTools/DetLayers/interface/ForwardDetLayer.h"

#include "TrackingTools/TrajectoryState/interface/FreeTrajectoryState.h"
#include "TrackingTools/GeomPropagators/interface/StraightLinePropagator.h"

using namespace GeomDetEnumerators;
using namespace std;

//------------------------------------------------------------------------------
const float MultipleScatteringGeometry::beamPipeR = 2.94;
const float MultipleScatteringGeometry::endflangesZ = 30;
const float MultipleScatteringGeometry::supportR = 19.;

//------------------------------------------------------------------------------
MultipleScatteringGeometry::MultipleScatteringGeometry(const GeometricSearchTracker &tracker) {
  vector<BarrelDetLayer const *> barrelLayers = tracker.barrelLayers();
  vector<BarrelDetLayer const *>::const_iterator ib;
  vector<ForwardDetLayer const *> forwardPosLayers = tracker.posForwardLayers();
  vector<ForwardDetLayer const *> forwardNegLayers = tracker.negForwardLayers();
  vector<ForwardDetLayer const *>::const_iterator ie;
  // barrelLayers = accessor.barrelLayers();
  for (ib = barrelLayers.begin(); ib != barrelLayers.end(); ib++)
    theLayers.push_back(*ib);

  //   forwardLayers = accessor.negativeEndcapLayers();
  for (ie = forwardPosLayers.begin(); ie != forwardPosLayers.end(); ie++)
    theLayers.push_back(*ie);
  for (ie = forwardNegLayers.begin(); ie != forwardNegLayers.end(); ie++)
    theLayers.push_back(*ie);
}

//------------------------------------------------------------------------------
vector<MSLayer> MultipleScatteringGeometry::detLayers() const {
  vector<MSLayer> result;
  vector<const DetLayer *>::const_iterator il;
  for (il = theLayers.begin(); il != theLayers.end(); il++)
    result.push_back(MSLayer(*il));
  return result;
}

//------------------------------------------------------------------------------
vector<MSLayer> MultipleScatteringGeometry::detLayers(float eta, float z, const MagneticField &bfield) const {
  vector<MSLayer> result;
  GlobalPoint zero(0, 0, z);
  float r = 1;
  float dirZ = r * sinh(eta);
  GlobalVector dir(r, 0., dirZ);
  FreeTrajectoryState fts(GlobalTrajectoryParameters(zero, dir, 1, &bfield));
  StraightLinePropagator propagator(&bfield, alongMomentum);
  vector<const DetLayer *>::const_iterator il;
  TrajectoryStateOnSurface tsos;
  for (il = theLayers.begin(); il != theLayers.end(); il++) {
    bool contains = false;
    //  if ((*il)->subDetector() != PixelBarrel && (*il)->subDetector()!= PixelEndcap) continue;

    if ((*il)->location() == barrel) {
      const BarrelDetLayer *bl = dynamic_cast<const BarrelDetLayer *>(*il);
      if (!bl)
        continue;
      tsos = propagator.propagate(fts, bl->specificSurface());
      if (!tsos.isValid())
        continue;
      float r = bl->specificSurface().radius();
      float dr = bl->specificSurface().bounds().thickness();
      float z = bl->position().z();
      float dz = bl->specificSurface().bounds().length();
      PixelRecoRange<float> rRange(r - dr / 2., r + dr / 2.);
      PixelRecoRange<float> zRange(z - dz / 2., z + dz / 2.);
      contains = rRange.inside(tsos.globalPosition().perp()) && zRange.inside(tsos.globalPosition().z());
      //     contains = bl->contains((*il)->toLocal(tsos.globalPosition()));
    } else if ((*il)->location() == endcap) {
      const ForwardDetLayer *fl = dynamic_cast<const ForwardDetLayer *>(*il);
      if (!fl)
        continue;
      if (fl->position().z() * eta < 0)
        continue;
      const BoundDisk &disk = fl->specificSurface();
      tsos = propagator.propagate(fts, disk);
      if (!tsos.isValid())
        continue;
      float zMin = disk.position().z() - disk.bounds().thickness() / 2;
      float zMax = disk.position().z() + disk.bounds().thickness() / 2;
      PixelRecoRange<float> rRange(disk.innerRadius(), disk.outerRadius());
      PixelRecoRange<float> zRange(zMin, zMax);
      contains = rRange.inside(tsos.globalPosition().perp()) && zRange.inside(tsos.globalPosition().z());
      //     contains = fl->contains(fl->toLocal(tsos.globalPosition()));
    }
    if (contains)
      result.push_back(MSLayer(*il));
  }
  return result;
}
//------------------------------------------------------------------------------
vector<MSLayer> MultipleScatteringGeometry::otherLayers(float eta) const {
  vector<MSLayer> result;
  // zero
  //  MSLayer zero(barrel, 0., MSLayer::Range(-15,15));
  //  result.push_back(zero);

  // beampipe
  MSLayer beampipe(barrel, beamPipeR, MSLayer::Range(-100, 100));

  result.push_back(beampipe);

  // endflanges
  PixelRecoPointRZ endfPoint = (eta > 0) ? PixelRecoPointRZ(endflangesZ / sinh(eta), endflangesZ)
                                         : PixelRecoPointRZ(-endflangesZ / sinh(eta), -endflangesZ);
  if (0 < endfPoint.r() && endfPoint.r() < supportR) {
    MSLayer endflanges(endcap, endfPoint.z(), MSLayer::Range(0.1, supportR - 0.1));
    result.push_back(endflanges);
  }

  // support
  MSLayer support(barrel, supportR, MSLayer::Range(-280, 280));
  result.push_back(support);

  return result;
}