InnerDeltaPhi Class Reference

#include <InnerDeltaPhi.h>

Public Types
typedef Basic2DVector< float >	Point2D

Public Member Functions
	InnerDeltaPhi (const DetLayer &outlayer, const DetLayer &layer, const TrackingRegion &region, const edm::EventSetup &iSetup, bool precise=true, float extraTolerance=0.f)
PixelRecoRange< float >	operator() (float xHit, float yHit, float zHit, float errRPhi) const

Private Member Functions
void	initBarrelLayer (const DetLayer &layer)
void	initForwardLayer (const DetLayer &layer, float zMinOrigin, float zMaxOrigin)
float	minRadius (float hitR, float hitZ) const
PixelRecoRange< float >	phiRange (const Point2D &hitXY, float zHit, float errRPhi) const

Private Attributes
int	ol
MultipleScatteringParametrisation	sigma
float	theA
float	theB
float	theExtraTolerance
bool	thePrecise
float	thePtMin
float	theRCurvature
bool	theRDefined
float	theRLayer
float	theROrigin
float	theThickness
Point2D	theVtx
float	theVtxZ

Detailed Description

Definition at line 17 of file InnerDeltaPhi.h.

Member Typedef Documentation

typedef Basic2DVector<float> InnerDeltaPhi::Point2D

Definition at line 20 of file InnerDeltaPhi.h.

Constructor & Destructor Documentation

InnerDeltaPhi::InnerDeltaPhi	(	const DetLayer &	outlayer,
		const DetLayer &	layer,
		const TrackingRegion &	region,
		const edm::EventSetup &	iSetup,
		bool	precise = true,
		float	extraTolerance = 0.f
	)

Definition at line 30 of file InnerDeltaPhi.cc.

References PixelRecoUtilities::bendingRadius(), initBarrelLayer(), initForwardLayer(), DetLayer::isBarrel(), TrackingRegion::originZBound(), thePtMin, theRCurvature, and theVtxZ.

  : thePrecise(precise),
    ol( outlayer.seqNum()), 
    theROrigin(region.originRBound()),
    theRLayer(0),
    theThickness(0),
    theExtraTolerance(extraTolerance),
    theA(0),
    theB(0),
    theVtxZ(region.origin().z()),
    thePtMin(region.ptMin()),
    theVtx(region.origin().x(),region.origin().y()),
    sigma(&layer,iSetup)
{
  float zMinOrigin = theVtxZ-region.originZBound();
  float zMaxOrigin = theVtxZ+region.originZBound();
  theRCurvature = PixelRecoUtilities::bendingRadius(thePtMin,iSetup);
 

  if (layer.isBarrel()) initBarrelLayer( layer);
  else initForwardLayer( layer, zMinOrigin, zMaxOrigin);

}

Member Function Documentation

void InnerDeltaPhi::initBarrelLayer ( const DetLayer &  layer )

private

Definition at line 59 of file InnerDeltaPhi.cc.

References Surface::bounds(), BarrelDetLayer::specificSurface(), GeometricSearchDet::surface(), theRDefined, theRLayer, theThickness, and Bounds::thickness().

Referenced by InnerDeltaPhi().

{
  const BarrelDetLayer& bl = static_cast<const BarrelDetLayer&>(layer); 
  float rLayer = bl.specificSurface().radius(); 

  // the maximal delta phi will be for the innermost hits
  theThickness = layer.surface().bounds().thickness();
  theRLayer = rLayer - 0.5f*theThickness;
  theRDefined = true;
}

void InnerDeltaPhi::initForwardLayer ( const DetLayer &  layer, float  zMinOrigin, float  zMaxOrigin  )

private

Definition at line 70 of file InnerDeltaPhi.cc.

References Surface::bounds(), GeometricSearchDet::position(), ForwardDetLayer::specificSurface(), GeometricSearchDet::surface(), theA, theB, theRDefined, theRLayer, theThickness, Bounds::thickness(), and PV3DBase< T, PVType, FrameType >::z().

Referenced by InnerDeltaPhi().

{
  const ForwardDetLayer &fl = static_cast<const ForwardDetLayer&>(layer);
  theRLayer = fl.specificSurface().innerRadius();
  float layerZ = layer.position().z();
  theThickness = layer.surface().bounds().thickness();
  float layerZmin = layerZ > 0 ? layerZ-0.5f*theThickness: layerZ+0.5f*theThickness;
  theB = layerZ > 0 ? zMaxOrigin : zMinOrigin;
  theA = layerZmin - theB;
  theRDefined = false;
}

float InnerDeltaPhi::minRadius ( float  hitR, float  hitZ  ) const

private

Definition at line 190 of file InnerDeltaPhi.cc.

References bookConverter::max, theA, theB, theRDefined, and theRLayer.

{
  if (theRDefined) return theRLayer;
  else {
    float rmin = (theA*hitR)/(hitZ-theB);
    return ( rmin> 0) ? std::max( rmin, theRLayer) : theRLayer;
  }
}

PixelRecoRange<float> InnerDeltaPhi::operator() ( float  xHit, float  yHit, float  zHit, float  errRPhi  ) const

inline

Definition at line 29 of file InnerDeltaPhi.h.

                                                                                             {
    return phiRange( Point2D(xHit,yHit), zHit, errRPhi); 
  }

PixelRecoRange< float > InnerDeltaPhi::phiRange ( const Point2D &  hitXY, float  zHit, float  errRPhi  ) const

private

Definition at line 85 of file InnerDeltaPhi.cc.

References funct::abs(), Basic2DVector< T >::barePhi(), SiPixelRawToDigiRegional_cfi::deltaPhi, Basic2DVector< T >::dot(), dt, alignCSCRings::e, f, M_PI, Basic2DVector< T >::mag(), margin, bookConverter::max, min(), ol, point, sigma, funct::sqr(), mathSSE::sqrt(), tree::t, theA, theB, theExtraTolerance, thePrecise, thePtMin, theRCurvature, theRDefined, theRLayer, theROrigin, theThickness, theVtx, theVtxZ, and Basic2DVector< T >::unit().

{
  float rLayer = theRLayer;
  bool checkCrossing = true;
  Point2D crossing;

  Point2D dHit = hitXY-theVtx;
  auto  dHitmag = dHit.mag();
  float  dLayer = 0.;
  float dL = 0.;
  //
  // compute crossing of stright track with inner layer
  //
  if (!theRDefined) {
    auto t = theA/(hitZ-theB); auto dt = std::abs(theThickness/(hitZ-theB));
    crossing = theVtx + t*dHit;
    rLayer =  crossing.mag();
    dLayer = t*dHitmag;           dL = dt * dHitmag; 
    checkCrossing = false;
    if (rLayer < theRLayer) {
      checkCrossing = true;
      rLayer = theRLayer;
      dL = 0.;
    } 
  }

  //
  // compute crossing of track with layer
  // dHit - from VTX to outer hit
  // rLayer - layer radius
  // dLayer - distance from VTX to inner layer in direction of dHit
  // vect(rLayer) = vect(rVTX) + vect(dHit).unit * dLayer
  //     rLayer^2 = (vect(rVTX) + vect(dHit).unit * dLayer)^2 and we have square eqation for dLayer 
  //
  // barrel case
  //

  if (checkCrossing) {
    auto vtxmag2 = theVtx.mag2();
    if (vtxmag2 < 1.e-10f) {
      dLayer = rLayer;
    }
    else { 
      // there are cancellation here....
      double var_c = vtxmag2-sqr(rLayer);
      double var_b = theVtx.dot(dHit.unit());
      double var_delta = sqr(var_b)-var_c;
      if (var_delta <=0.) var_delta = 0;
      dLayer = -var_b + std::sqrt(var_delta); //only the value along vector is OK. 
    }
    crossing = theVtx+ dHit.unit() * dLayer;
    float cosCross = std::abs( dHit.unit().dot(crossing.unit()));
    dL = theThickness/cosCross; 
  }


  // track is crossing layer with angle such as:
  // this factor should be taken in computation of eror projection
  auto cosCross = std::abs( dHit.unit().dot(crossing.unit()));

  auto alphaHit = cropped_asin( dHitmag/(2*theRCurvature)); 
  auto deltaPhi = std::abs( alphaHit - cropped_asin( dLayer/(2*theRCurvature)));
  deltaPhi *= dLayer/(rLayer*cosCross);  

  // additinal angle due to not perpendicular stright line crossing  (for displaced beam)
  //  double dPhiCrossing = (cosCross > 0.9999) ? 0 : dL *  sqrt(1-sqr(cosCross))/ rLayer;
  Point2D crossing2 = theVtx + dHit.unit()* (dLayer+dL);
  auto phicross2 = crossing2.barePhi();  
  auto phicross1 = crossing.barePhi();
  auto dphicross = phicross2-phicross1;
  if (dphicross < -float(M_PI)) dphicross += float(2*M_PI);
  if (dphicross >  float(M_PI)) dphicross -= float(2*M_PI);
  if (dphicross > float(M_PI/2)) dphicross = 0.;  // something wrong?
  phicross2 = phicross1 + dphicross;
        

  // compute additional delta phi due to origin radius
  auto deltaPhiOrig = cropped_asin( theROrigin * (dHitmag-dLayer) / (dHitmag*dLayer));
  deltaPhiOrig *= dLayer/(rLayer*cosCross);

  // inner hit error taken as constant
  auto deltaPhiHit = theExtraTolerance / rLayer;

  // outer hit error
//   double deltaPhiHitOuter = errRPhi/rLayer; 
  auto deltaPhiHitOuter = errRPhi/hitXY.mag();

  auto margin = deltaPhi+deltaPhiOrig+deltaPhiHit+deltaPhiHitOuter ;

  if (thePrecise) {
    // add multiple scattering correction
    PixelRecoPointRZ zero(0., theVtxZ);
    PixelRecoPointRZ point(hitXY.mag(), hitZ);
    auto scatt = 3.f*sigma(thePtMin,zero, point, ol) / rLayer; 
   
    margin += scatt ;
  }
  
  return PixelRecoRange<float>( std::min(phicross1,phicross2)-margin, 
                                std::max(phicross1,phicross2)+margin);
}

Member Data Documentation

int InnerDeltaPhi::ol

private

Definition at line 37 of file InnerDeltaPhi.h.

Referenced by phiRange().

MultipleScatteringParametrisation InnerDeltaPhi::sigma

private

Definition at line 54 of file InnerDeltaPhi.h.

Referenced by phiRange().

float InnerDeltaPhi::theA

private

Definition at line 45 of file InnerDeltaPhi.h.

Referenced by initForwardLayer(), minRadius(), and phiRange().

float InnerDeltaPhi::theB

private

Definition at line 46 of file InnerDeltaPhi.h.

Referenced by initForwardLayer(), minRadius(), and phiRange().

float InnerDeltaPhi::theExtraTolerance

private

Definition at line 44 of file InnerDeltaPhi.h.

Referenced by phiRange().

bool InnerDeltaPhi::thePrecise

private

Definition at line 36 of file InnerDeltaPhi.h.

Referenced by phiRange().

float InnerDeltaPhi::thePtMin

private

Definition at line 49 of file InnerDeltaPhi.h.

Referenced by InnerDeltaPhi(), and phiRange().

float InnerDeltaPhi::theRCurvature

private

Definition at line 43 of file InnerDeltaPhi.h.

Referenced by InnerDeltaPhi(), and phiRange().

bool InnerDeltaPhi::theRDefined

private

Definition at line 35 of file InnerDeltaPhi.h.

Referenced by initBarrelLayer(), initForwardLayer(), minRadius(), and phiRange().

float InnerDeltaPhi::theRLayer

private

Definition at line 40 of file InnerDeltaPhi.h.

Referenced by initBarrelLayer(), initForwardLayer(), minRadius(), and phiRange().

float InnerDeltaPhi::theROrigin

private

Definition at line 39 of file InnerDeltaPhi.h.

Referenced by phiRange().

float InnerDeltaPhi::theThickness

private

Definition at line 41 of file InnerDeltaPhi.h.

Referenced by initBarrelLayer(), initForwardLayer(), and phiRange().

Point2D InnerDeltaPhi::theVtx

private

Definition at line 51 of file InnerDeltaPhi.h.

Referenced by phiRange().

float InnerDeltaPhi::theVtxZ

private

Definition at line 48 of file InnerDeltaPhi.h.

Referenced by InnerDeltaPhi(), and phiRange().