FTSFromVertexToPointFactory Class Reference

#include <FTSFromVertexToPointFactory.h>

Static Public Member Functions
static FreeTrajectoryState	get (MagneticField const &magField, GlobalPoint const &xmeas, GlobalPoint const &xvert, float momentum, TrackCharge charge)

Detailed Description

Description: Utility class to create FTS from supercluster

Implementation: should go somewhere else in the future

Definition at line 29 of file FTSFromVertexToPointFactory.h.

Member Function Documentation

FreeTrajectoryState FTSFromVertexToPointFactory::get ( MagneticField const &  magField, GlobalPoint const &  xmeas, GlobalPoint const &  xvert, float  momentum, TrackCharge  charge  )

static

Definition at line 22 of file FTSFromVertexToPointFactory.cc.

References alpha, funct::C, funct::cos(), MagneticField::inTesla(), PV3DBase< T, PVType, FrameType >::perp(), phi, PV3DBase< T, PVType, FrameType >::phi(), RecoTauCleanerPlugins::pt, funct::sin(), PV3DBase< T, PVType, FrameType >::theta(), theta(), and PV3DBase< T, PVType, FrameType >::z().

Referenced by Options.Options::__getitem__(), betterConfigParser.BetterConfigParser::__updateDict(), ElectronSeedAnalyzer::analyze(), HLTPMMassFilter::approxMomAtVtx(), PixelHitMatcher::compatibleHits(), PixelHitMatcher::compatibleSeeds(), betterConfigParser.BetterConfigParser::getCompares(), betterConfigParser.BetterConfigParser::getGeneral(), betterConfigParser.BetterConfigParser::getResultingSection(), and SeedFilter::seeds().

{
  double BInTesla = magField.inTesla(xmeas).z();
  GlobalVector xdiff = xmeas - xvert;
  double theta = xdiff.theta();
  double phi= xdiff.phi();
  double pt = momentum*sin(theta);
  double pz = momentum*cos(theta);
  double pxOld = pt*cos(phi);
  double pyOld = pt*sin(phi);

  double RadCurv = 100*pt/(BInTesla*0.29979);
  double alpha = asin(0.5*xdiff.perp()/RadCurv);

  float ca = cos(charge*alpha);
  float sa = sin(charge*alpha);
  double pxNew =   ca*pxOld + sa*pyOld;
  double pyNew =  -sa*pxOld + ca*pyOld;
  GlobalVector pNew(pxNew, pyNew, pz);  

  GlobalTrajectoryParameters gp(xmeas, pNew, charge, & magField);
  
  AlgebraicSymMatrix55 C = AlgebraicMatrixID();
  FreeTrajectoryState VertexToPoint(gp,CurvilinearTrajectoryError(C));

  return VertexToPoint;
}