Belle II Software development
SimplePXDStateFilter.cc
1/**************************************************************************
2 * basf2 (Belle II Analysis Software Framework) *
3 * Author: The Belle II Collaboration *
4 * *
5 * See git log for contributors and copyright holders. *
6 * This file is licensed under LGPL-3.0, see LICENSE.md. *
7 **************************************************************************/
8#include <tracking/ckf/pxd/filters/states/SimplePXDStateFilter.h>
9
10#include <tracking/trackFindingCDC/eventdata/trajectories/CDCTrajectory3D.h>
11#include <tracking/trackFindingCDC/eventdata/trajectories/CDCTrajectory2D.h>
12#include <tracking/trackFindingCDC/eventdata/trajectories/CDCTrajectorySZ.h>
13#include <tracking/trackFindingCDC/geometry/Vector3D.h>
14
15#include <tracking/trackFindingCDC/eventdata/trajectories/CDCBFieldUtil.h>
16#include <tracking/spacePointCreation/SpacePoint.h>
17#include <tracking/dataobjects/RecoTrack.h>
18
19using namespace Belle2;
20using namespace TrackFindingCDC;
21
22namespace {
24 unsigned int getPTRange(const TrackFindingCDC::Vector3D& momentum)
25 {
26 const double pT = momentum.xy().norm();
27 if (pT > 0.4) {
28 return 0;
29 } else if (pT > 0.2) {
30 return 1;
31 } else {
32 return 2;
33 }
34 }
35}
36
40
45
47{
48 const std::vector<TrackFindingCDC::WithWeight<const CKFToPXDState*>>& previousStates = pair.first;
49 CKFToPXDState* currentState = pair.second;
50
51 const auto* spacePoint = currentState->getHit();
52
53 genfit::MeasuredStateOnPlane firstMeasurement;
54 if (currentState->mSoPSet()) {
55 firstMeasurement = currentState->getMeasuredStateOnPlane();
56 } else {
57 firstMeasurement = previousStates.back()->getMeasuredStateOnPlane();
58 }
59
60 Vector3D position = Vector3D(firstMeasurement.getPos());
61 Vector3D momentum = Vector3D(firstMeasurement.getMom());
62
63 const Vector3D hitPosition = static_cast<Vector3D>(spacePoint->getPosition());
64
65 const bool sameHemisphere = fabs(position.phi() - hitPosition.phi()) < TMath::PiOver2();
66 if (not sameHemisphere) {
67 return NAN;
68 }
69
70 double valueToCheck;
71 const MaximalValueArray* maximumValues;
72
73 if (not currentState->isFitted() and not currentState->mSoPSet()) {
74 // Filter 1
75 const RecoTrack* cdcTrack = previousStates.front()->getSeed();
76
77 B2ASSERT("A path without a seed?", cdcTrack);
78
79 const CDCTrajectory3D trajectory(position, 0, momentum, cdcTrack->getChargeSeed(), m_cachedBField);
80
81 const double arcLength = trajectory.calcArcLength2D(hitPosition);
82 const Vector2D& trackPositionAtHit2D = trajectory.getTrajectory2D().getPos2DAtArcLength2D(arcLength);
83 const double trackPositionAtHitZ = trajectory.getTrajectorySZ().mapSToZ(arcLength);
84 const Vector3D trackPositionAtHit(trackPositionAtHit2D, trackPositionAtHitZ);
85 const Vector3D differenceHelix = trackPositionAtHit - hitPosition;
86
87 valueToCheck = differenceHelix.xy().norm();
88 maximumValues = &m_param_maximumHelixDistanceXY;
89 } else if (not currentState->isFitted()) {
90 // Filter 2
91 const double residual = m_kalmanStepper.calculateResidual(firstMeasurement, *currentState);
92
93 valueToCheck = residual;
94 maximumValues = &m_param_maximumResidual;
95 } else {
96 // Filter 3
97 valueToCheck = currentState->getChi2();
98 maximumValues = &m_param_maximumChi2;
99 }
100
101 const unsigned int layer = currentState->getGeometricalLayer();
102 if (valueToCheck > (*maximumValues)[layer - 1][getPTRange(momentum)]) {
103 return NAN;
104 }
105
106 return valueToCheck;
107}
const genfit::MeasuredStateOnPlane & getMeasuredStateOnPlane() const
Get the mSoP if already set during extrapolation (or fitting)
Definition CKFState.h:93
const Hit * getHit() const
Return the SP this state is related to. May be nullptr.
Definition CKFState.h:66
double getChi2() const
Return the chi2 set during fitting. Is only valid after fitting.
Definition CKFState.h:72
bool isFitted() const
Check if state was already fitted.
Definition CKFState.h:100
bool mSoPSet() const
Is the mSoP already set? (= state was already extrapolated)
Definition CKFState.h:106
Specialized CKF State for extrapolating into the PXD.
unsigned int getGeometricalLayer() const
Extract the real layer this state sits on.
This is the Reconstruction Event-Data Model Track.
Definition RecoTrack.h:79
short int getChargeSeed() const
Return the charge seed stored in the reco track. ATTENTION: This is not the fitted charge.
Definition RecoTrack.h:508
TrackFindingCDC::Weight operator()(const BasePXDStateFilter::Object &pair) final
Function to evaluate the object.
static constexpr const MaximalValueArray m_param_maximumHelixDistanceXY
Maximum distance calculated with helix extrapolation in filter 1. Numbers calculated on MC.
static constexpr const MaximalValueArray m_param_maximumChi2
Maximum chi^2 in filter 3. Numbers calculated on MC.
void beginRun() final
Set the cached B field.
static constexpr const MaximalValueArray m_param_maximumResidual
Maximum distance calculated with normal extrapolation in filter 2. Numbers calculated on MC.
PXDKalmanStepper m_kalmanStepper
Kalman stepper (CKF) for PXD.
double m_cachedBField
Cache for the B field at the IP.
double[2][3] MaximalValueArray
Shortcut for a 2x3 array.
static double getBFieldZ()
Getter for the signed magnetic field strength in z direction at the origin ( in Tesla )
Vector2D getPos2DAtArcLength2D(double arcLength2D)
Getter for the position at a given two dimensional arc length.
Particle full three dimensional trajectory.
double calcArcLength2D(const Vector3D &point) const
Calculate the travel distance from the start position of the trajectory.
CDCTrajectory2D getTrajectory2D() const
Getter for the two dimensional trajectory.
CDCTrajectorySZ getTrajectorySZ() const
Getter for the sz trajectory.
double mapSToZ(const double s=0) const
Translates the travel distance to the z coordinate.
std::pair< const std::vector< TrackFindingCDC::WithWeight< const CKFToPXDState * > >, CKFToPXDState * > Object
Definition Filter.dcl.h:35
A two dimensional vector which is equipped with functions for correct handling of orientation relate...
Definition Vector2D.h:32
A three dimensional vector.
Definition Vector3D.h:33
STL class.
HepGeom::Vector3D< double > Vector3D
3D Vector
Definition Cell.h:34
Abstract base class for different kinds of events.