MultipleScatteringParametrisation Class Reference

#include <MultipleScatteringParametrisation.h>

List of all members.

Public Types
enum	Consecutive { notAssumeConsecutive, useConsecutive }
enum	X0Source { useDetLayer = 0, useX0AtEta = 1, useX0DataAveraged = 2 }
Public Member Functions
	MultipleScatteringParametrisation (const DetLayer *layer, const edm::EventSetup &iSetup, X0Source x0source=useX0AtEta)
float	operator() (float pt, const PixelRecoPointRZ &point1, const PixelRecoPointRZ &point2, Consecutive consecutive=notAssumeConsecutive, float transverseIP=0.) const
float	operator() (float pt, float cotTheta, const PixelRecoPointRZ &point, float transverseIP=0.) const
float	operator() (float pt, float cotTheta, float transverseIP=0.) const
Static Public Member Functions
static void	initKeepers (const edm::EventSetup &iSetup)
Private Attributes
MSLayer	theLayer
MSLayersKeeper const *	theLayerKeeper
Static Private Attributes
static const float	x0ToSigma = 0.0136f

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Detailed Description

Parametrisation of multiple scattering sigma in tracker.

Definition at line 20 of file MultipleScatteringParametrisation.h.

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Member Enumeration Documentation

enum MultipleScatteringParametrisation::Consecutive

Enumerator:

notAssumeConsecutive
useConsecutive

Definition at line 27 of file MultipleScatteringParametrisation.h.

{ notAssumeConsecutive, useConsecutive };

enum MultipleScatteringParametrisation::X0Source

Enumerator:

useDetLayer
useX0AtEta
useX0DataAveraged

Definition at line 26 of file MultipleScatteringParametrisation.h.

{ useDetLayer=0, useX0AtEta=1, useX0DataAveraged=2 };

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Constructor & Destructor Documentation

MultipleScatteringParametrisation::MultipleScatteringParametrisation	(	const DetLayer *	layer,
		const edm::EventSetup &	iSetup,
		X0Source	x0source = useX0AtEta
	)

Definition at line 52 of file MultipleScatteringParametrisation.cc.

References initKeepers(), MSLayersKeeper::layer(), theLayer, and theLayerKeeper.

                                                                                                         :
  theLayerKeeper(keepers(x0Source))
{

  // FIXME not thread safe: move elsewhere...
  initKeepers(iSetup);

  if (!layer) return;
  theLayer = theLayerKeeper->layer(layer);
} 

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Member Function Documentation

void MultipleScatteringParametrisation::initKeepers

(

const edm::EventSetup &

iSetup

)

[static]

Definition at line 45 of file MultipleScatteringParametrisation.cc.

References init.

Referenced by MultipleScatteringParametrisation().

                                                                              {
  const_cast<Keepers&>(keepers).init(iSetup);
}

float MultipleScatteringParametrisation::operator()	(	float	pt,
		const PixelRecoPointRZ &	point1,
		const PixelRecoPointRZ &	point2,
		Consecutive	consecutive = notAssumeConsecutive,
		float	transverseIP = 0.
	)		const

MS sigma at the layer for which parametrisation is initialised; particle assumed to be measured at point1 and point2, it is assumed that layer is between point1 and point2. layer by layer contribution is calculated

Definition at line 86 of file MultipleScatteringParametrisation.cc.

References PixelRecoLineRZ::cotLine(), MSLayer::crossing(), MSLayersKeeper::layers(), PixelRecoPointRZ::r(), mathSSE::sqrt(), MSLayersAtAngle::sumX0D(), theLayer, theLayerKeeper, useConsecutive, MSLayer::x0(), and x0ToSigma.

{   


  PixelRecoLineRZ lineIO(pointI, pointO, tip);
  PixelRecoPointRZ pointM = theLayer.crossing(lineIO).first;
  float cotTheta = lineIO.cotLine();

  if (consecutive==useConsecutive) {
    float dist = fabs(  (pointO.r()-pointM.r())
                      * (pointM.r()-pointI.r())
                      / (pointO.r()-pointI.r()) );
    return  x0ToSigma * sqrt(theLayer.x0(cotTheta)) * dist /pT;
  } else {
    const MSLayersAtAngle & layersAtEta = theLayerKeeper->layers(cotTheta);
    float sumX0D = layersAtEta.sumX0D(pointI, pointM, pointO);
    return x0ToSigma * sumX0D /pT;
  }
}

float MultipleScatteringParametrisation::operator()	(	float	pt,
		float	cotTheta,
		const PixelRecoPointRZ &	point,
		float	transverseIP = 0.
	)		const

MS sigma at the layer for which parametrisation is initialised; particle assumed to come from constraint point (inner to layer). layer by layer contribution is calculated

Definition at line 72 of file MultipleScatteringParametrisation.cc.

References MSLayer::crossing(), MSLayersKeeper::layers(), MSLayersAtAngle::sumX0D(), theLayer, theLayerKeeper, and x0ToSigma.

{

  PixelRecoLineRZ lineIO(pointI, cotTheta, tip);
  PixelRecoPointRZ pointO = theLayer.crossing(lineIO).first;

  const MSLayersAtAngle & layersAtEta = theLayerKeeper->layers(cotTheta);
  
  float sumX0D = layersAtEta.sumX0D(pointI, pointO);
  return x0ToSigma * sumX0D /pT;
}

float MultipleScatteringParametrisation::operator()	(	float	pt,
		float	cotTheta,
		float	transverseIP = 0.
	)		const

MS sigma at the layer for which parametrisation is initialised; particle assumed to come from nominal vertex, "fast" methods called

Definition at line 64 of file MultipleScatteringParametrisation.cc.

References MSLayer::sumX0D(), theLayer, and x0ToSigma.

{
  float sumX0D = theLayer.sumX0D(cotTheta); 
  return x0ToSigma * sumX0D /pT;
}

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Member Data Documentation

MSLayer MultipleScatteringParametrisation::theLayer [private]

Definition at line 58 of file MultipleScatteringParametrisation.h.

Referenced by MultipleScatteringParametrisation(), and operator()().

MSLayersKeeper const* MultipleScatteringParametrisation::theLayerKeeper [private]

Definition at line 59 of file MultipleScatteringParametrisation.h.

Referenced by MultipleScatteringParametrisation(), and operator()().

const float MultipleScatteringParametrisation::x0ToSigma = 0.0136f [static, private]

Definition at line 60 of file MultipleScatteringParametrisation.h.

Referenced by operator()().