TSCBLBuilderNoMaterial.cc

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#include "TrackingTools/PatternTools/interface/TSCBLBuilderNoMaterial.h"
#include "TrackingTools/AnalyticalJacobians/interface/AnalyticalCurvilinearJacobian.h"
#include "TrackingTools/PatternTools/interface/TwoTrackMinimumDistance.h"
#include "FWCore/MessageLogger/interface/MessageLogger.h"
 
using namespace std;
 
TrajectoryStateClosestToBeamLine TSCBLBuilderNoMaterial::operator()(const FreeTrajectoryState& originalFTS,
                                                                    const reco::BeamSpot& beamSpot) const {
  TwoTrackMinimumDistance ttmd;
  bool status = ttmd.calculate(
      originalFTS.parameters(),
      GlobalTrajectoryParameters(GlobalPoint(beamSpot.position().x(), beamSpot.position().y(), beamSpot.position().z()),
                                 GlobalVector(beamSpot.dxdz(), beamSpot.dydz(), 1.),
                                 0,
                                 &(originalFTS.parameters().magneticField())));
  if (!status) {
    LogDebug("TrackingTools|PatternTools")
        << "TSCBLBuilderNoMaterial: Failure in TTMD when searching for PCA of track to beamline.\n"
        << "TrajectoryStateClosestToBeamLine is now invalid.";
    return TrajectoryStateClosestToBeamLine();
  }
 
  pair<GlobalPoint, GlobalPoint> points = ttmd.points();
 
  GlobalPoint xTrack = points.first;
  GlobalVector pTrack = GlobalVector(
      GlobalVector::Cylindrical(originalFTS.momentum().perp(), ttmd.firstAngle(), originalFTS.momentum().z()));
 
  double s = ttmd.pathLength().first;
 
  FreeTrajectoryState theFTS;
  if (originalFTS.hasError()) {
    const AlgebraicSymMatrix55& errorMatrix = originalFTS.curvilinearError().matrix();
    AnalyticalCurvilinearJacobian curvilinJacobian(originalFTS.parameters(), xTrack, pTrack, s);
    const AlgebraicMatrix55& jacobian = curvilinJacobian.jacobian();
    CurvilinearTrajectoryError cte(ROOT::Math::Similarity(jacobian, errorMatrix));
 
    theFTS = FreeTrajectoryState(
        GlobalTrajectoryParameters(xTrack, pTrack, originalFTS.charge(), &(originalFTS.parameters().magneticField())),
        cte);
  } else {
    theFTS = FreeTrajectoryState(
        GlobalTrajectoryParameters(xTrack, pTrack, originalFTS.charge(), &(originalFTS.parameters().magneticField())));
  }
  return TrajectoryStateClosestToBeamLine(theFTS, points.second, beamSpot);
}