Belle II Software light-2503-ceres
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ClusterUtils Class Reference
Packages » analysis

Class to provide momentum-related information from ECLClusters. More...

#include <ClusterUtils.h>

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Public Member Functions

 ClusterUtils ()
 Constructor.
 
const ROOT::Math::PxPyPzEVector GetCluster4MomentumFromCluster (const ECLCluster *cluster, ECLCluster::EHypothesisBit hypo)
 Returns cluster four momentum vector.
 
const ROOT::Math::PxPyPzEVector Get4MomentumFromCluster (const ECLCluster *cluster, ECLCluster::EHypothesisBit hypo)
 Returns four momentum vector.
 
const ROOT::Math::PxPyPzEVector Get4MomentumFromCluster (const ECLCluster *cluster, const ROOT::Math::XYZVector &vertex, ECLCluster::EHypothesisBit hypo)
 Returns four momentum vector.
 
const TMatrixD GetJacobiMatrix4x6FromCluster (const ECLCluster *cluster, ECLCluster::EHypothesisBit hypo)
 Returns 4x6 Jacobi matrix (px, py, pz, E)
 
const TMatrixD GetJacobiMatrix4x6FromCluster (const ECLCluster *cluster, const ROOT::Math::XYZVector &vertex, ECLCluster::EHypothesisBit hypo)
 Returns 4x6 Jacobi matrix (px, py, pz, E)
 
const TMatrixDSym GetCovarianceMatrix3x3FromCluster (const ECLCluster *cluster, int particleHypo=Const::photon.getPDGCode())
 Returns 3x3 covariance matrix (E, theta, phi)
 
const TMatrixDSym GetCovarianceMatrix4x4FromCluster (const ECLCluster *cluster, const TMatrixD &jacobiMatrix)
 Returns 4x4 covariance matrix (px, py, pz, E)
 
const TMatrixDSym GetCovarianceMatrix4x4FromCluster (const ECLCluster *cluster, const TMatrixDSym &covmatvertex, const TMatrixD &jacobiMatrix)
 Returns 4x4 covariance matrix (px, py, pz, E)
 
const TMatrixDSym GetCovarianceMatrix7x7FromCluster (const ECLCluster *cluster, const TMatrixD &jacobiMatrix)
 Returns 7x7 covariance matrix (px, py, pz, E, x, y, z)
 
const TMatrixDSym GetCovarianceMatrix7x7FromCluster (const ECLCluster *cluster, const TMatrixDSym &covmatvertex, const TMatrixD &jacobiMatrix)
 Returns 7x7 covariance matrix (px, py, pz, E, x, y, z)
 
const ROOT::Math::XYZVector GetIPPosition ()
 Returns default IP position from beam parameters.
 
const TMatrixDSym GetIPPositionCovarianceMatrix ()
 Returns default IP position covariance matrix from beam parameters.
 

Private Attributes

DBObjPtr< BeamSpot > m_beamSpotDB
 Beam spot database object.
 
OptionalDBObjPtr< ECLPhotonEnergyResolution > m_photonEnergyResolutionDB
 Photon energy resolution database object.
 
OptionalDBObjPtr< ECLPhotonEnergyResolution > m_neutronPositionResolutionDB {"neutronPositionResolutionDB"}
 Neutron position resolution database objects.
 
OptionalDBObjPtr< ECLPhotonEnergyResolution > m_antiNeutronPositionResolutionDB {"antiNeutronPositionResolutionDB"}
 Antineutron position resolution database objects.
 
OptionalDBObjPtr< ECLPhotonEnergyResolution > m_kaonPositionResolutionDB {"kaonPositionResolutionDB"}
 Neutral kaon position resolution database objects.
 

Detailed Description

Class to provide momentum-related information from ECLClusters.

This requires the prior knowledge of the particle type (e.g., photon), and a vertex hypothesis. The default vertex hypothesis is taken from the beamparameters.

Definition at line 38 of file ClusterUtils.h.

Member Function Documentation

◆ Get4MomentumFromCluster() [1/2]

const PxPyPzEVector Get4MomentumFromCluster ( const ECLCluster *  cluster,
const ROOT::Math::XYZVector &  vertex,
ECLCluster::EHypothesisBit  hypo 
)

Returns four momentum vector.

Returns
const four momentum vector

Definition at line 32 of file ClusterUtils.cc.

34{
35
36 // Get particle direction from vertex and reconstructed cluster position.
37 XYZVector direction(cluster->getClusterPosition().X() - vertex.X(),
38 cluster->getClusterPosition().Y() - vertex.Y(),
39 cluster->getClusterPosition().Z() - vertex.Z());
40
41 // Always ignore mass here (even for neutral hadrons) therefore the magnitude
42 // of the momentum is equal to the cluster energy under this hypo.
43 const double E = cluster->getEnergy(hypo); // must not be changed or clusterE getters will be wrong
44 const double px = E * sin(direction.Theta()) * cos(direction.Phi());
45 const double py = E * sin(direction.Theta()) * sin(direction.Phi());
46 const double pz = E * cos(direction.Theta());
47
48 const PxPyPzEVector l(px, py, pz, E);
49 return l;
50}

◆ Get4MomentumFromCluster() [2/2]

const PxPyPzEVector Get4MomentumFromCluster ( const ECLCluster *  cluster,
ECLCluster::EHypothesisBit  hypo 
)

Returns four momentum vector.

Returns
const four momentum vector

Definition at line 25 of file ClusterUtils.cc.

26{
27
28 // Use the default vertex from the beam parameters if none is given.
29 return Get4MomentumFromCluster(cluster, GetIPPosition(), hypo);
30}
Belle2::ClusterUtils::Get4MomentumFromCluster
const ROOT::Math::PxPyPzEVector Get4MomentumFromCluster(const ECLCluster *cluster, ECLCluster::EHypothesisBit hypo)
Returns four momentum vector.
Definition: ClusterUtils.cc:25
Belle2::ClusterUtils::GetIPPosition
const ROOT::Math::XYZVector GetIPPosition()
Returns default IP position from beam parameters.
Definition: ClusterUtils.cc:241

◆ GetCluster4MomentumFromCluster()

const PxPyPzEVector GetCluster4MomentumFromCluster ( const ECLCluster *  cluster,
ECLCluster::EHypothesisBit  hypo 
)

Returns cluster four momentum vector.

Returns
const cluster four momentum vector

Definition at line 19 of file ClusterUtils.cc.

20{
21 // Use the geometry origin (0,0,0) and *not* the IP position
22 return Get4MomentumFromCluster(cluster, XYZVector(0.0, 0.0, 0.0), hypo);
23}

◆ GetCovarianceMatrix3x3FromCluster()

const TMatrixDSym GetCovarianceMatrix3x3FromCluster ( const ECLCluster *  cluster,
int  particleHypo = Const::photon.getPDGCode() 
)

Returns 3x3 covariance matrix (E, theta, phi)

Returns
const TMatrixDSym

Replace fixed energy resolution value by derived value from the DB if present

Definition at line 134 of file ClusterUtils.cc.

135{
136 // Get the covariance matrix (energy, phi, theta) from the ECL cluster.
137 TMatrixDSym covmatecl = cluster->getCovarianceMatrix3x3();
138
142 if (cluster->hasHypothesis(ECLCluster::EHypothesisBit::c_nPhotons)) {
143 if (m_photonEnergyResolutionDB.isValid() and particleHypo == Const::photon.getPDGCode()) {
144 double pEnergy = cluster->getEnergy(ECLCluster::EHypothesisBit::c_nPhotons);
145 double pTheta = cluster->getTheta();
146 double pPhi = cluster->getPhi();
147
148 double energyCovarianceElement = m_photonEnergyResolutionDB->getRelativeEnergyResolution(pEnergy, pTheta, pPhi);
149 if (energyCovarianceElement != -1) {
150 covmatecl(0, 0) = energyCovarianceElement * pEnergy * energyCovarianceElement * pEnergy;
151 }
152 } else if (particleHypo != Const::photon.getPDGCode()) {
153
154 // Using hadron mass hypothesis but photon cluster reconstruction hypothesis, load correct position resolution from DB
155 // for hadrons, parameterized as function of cluster uncorrected energy
156 double pClusterUncorrEnergy = cluster->getEnergyRaw();
157 double pTheta = cluster->getTheta();
158 double pPhi = cluster->getPhi();
159 if (particleHypo == Const::neutron.getPDGCode() and m_neutronPositionResolutionDB.isValid()) {
160 double phiResolution = m_neutronPositionResolutionDB->getThetaPhiResolution(pClusterUncorrEnergy, pTheta, pPhi, 0);
161 double thetaResolution = m_neutronPositionResolutionDB->getThetaPhiResolution(pClusterUncorrEnergy, pTheta, pPhi, 1);
162 covmatecl(1, 1) = phiResolution * phiResolution;
163 covmatecl(2, 2) = thetaResolution * thetaResolution;
164 } else if (particleHypo == Const::antiNeutron.getPDGCode() and m_antiNeutronPositionResolutionDB.isValid()) {
165 double phiResolution = m_antiNeutronPositionResolutionDB->getThetaPhiResolution(pClusterUncorrEnergy, pTheta, pPhi, 0);
166 double thetaResolution = m_antiNeutronPositionResolutionDB->getThetaPhiResolution(pClusterUncorrEnergy, pTheta, pPhi, 1);
167 covmatecl(1, 1) = phiResolution * phiResolution;
168 covmatecl(2, 2) = thetaResolution * thetaResolution;
169 } else if (particleHypo == Const::Klong.getPDGCode() and m_kaonPositionResolutionDB.isValid()) {
170 double phiResolution = m_kaonPositionResolutionDB->getThetaPhiResolution(pClusterUncorrEnergy, pTheta, pPhi, 0);
171 double thetaResolution = m_kaonPositionResolutionDB->getThetaPhiResolution(pClusterUncorrEnergy, pTheta, pPhi, 1);
172 covmatecl(1, 1) = phiResolution * phiResolution;
173 covmatecl(2, 2) = thetaResolution * thetaResolution;
174 }
175 }
176 }
177
178 return covmatecl;
179}
Belle2::ClusterUtils::m_photonEnergyResolutionDB
OptionalDBObjPtr< ECLPhotonEnergyResolution > m_photonEnergyResolutionDB
Photon energy resolution database object.
Definition: ClusterUtils.h:132
Belle2::ClusterUtils::m_antiNeutronPositionResolutionDB
OptionalDBObjPtr< ECLPhotonEnergyResolution > m_antiNeutronPositionResolutionDB
Antineutron position resolution database objects.
Definition: ClusterUtils.h:142
Belle2::ClusterUtils::m_kaonPositionResolutionDB
OptionalDBObjPtr< ECLPhotonEnergyResolution > m_kaonPositionResolutionDB
Neutral kaon position resolution database objects.
Definition: ClusterUtils.h:147
Belle2::ClusterUtils::m_neutronPositionResolutionDB
OptionalDBObjPtr< ECLPhotonEnergyResolution > m_neutronPositionResolutionDB
Neutron position resolution database objects.
Definition: ClusterUtils.h:137
Belle2::Const::ParticleType::getPDGCode
int getPDGCode() const
PDG code.
Definition: Const.h:473
Belle2::Const::neutron
static const ParticleType neutron
neutron particle
Definition: Const.h:675
Belle2::Const::Klong
static const ParticleType Klong
K^0_L particle.
Definition: Const.h:678
Belle2::Const::antiNeutron
static const ParticleType antiNeutron
Anti-neutron particle.
Definition: Const.h:676
Belle2::Const::photon
static const ParticleType photon
photon particle
Definition: Const.h:673
Belle2::ECLCluster::EHypothesisBit::c_nPhotons
@ c_nPhotons
CR is split into n photons (N1)

◆ GetCovarianceMatrix4x4FromCluster() [1/2]

const TMatrixDSym GetCovarianceMatrix4x4FromCluster ( const ECLCluster *  cluster,
const TMatrixD &  jacobiMatrix 
)

Returns 4x4 covariance matrix (px, py, pz, E)

Returns
const TMatrixDSym

Definition at line 181 of file ClusterUtils.cc.

182{
183
184 return GetCovarianceMatrix4x4FromCluster(cluster, GetIPPositionCovarianceMatrix(), jacobiMatrix);
185}
Belle2::ClusterUtils::GetCovarianceMatrix4x4FromCluster
const TMatrixDSym GetCovarianceMatrix4x4FromCluster(const ECLCluster *cluster, const TMatrixD &jacobiMatrix)
Returns 4x4 covariance matrix (px, py, pz, E)
Definition: ClusterUtils.cc:181
Belle2::ClusterUtils::GetIPPositionCovarianceMatrix
const TMatrixDSym GetIPPositionCovarianceMatrix()
Returns default IP position covariance matrix from beam parameters.
Definition: ClusterUtils.cc:251

◆ GetCovarianceMatrix4x4FromCluster() [2/2]

const TMatrixDSym GetCovarianceMatrix4x4FromCluster ( const ECLCluster *  cluster,
const TMatrixDSym &  covmatvertex,
const TMatrixD &  jacobiMatrix 
)

Returns 4x4 covariance matrix (px, py, pz, E)

Returns
const TMatrixDSym

Definition at line 187 of file ClusterUtils.cc.

189{
190
191 // Get the covariance matrix (energy, phi, theta)
192 TMatrixDSym covmatecl = GetCovarianceMatrix3x3FromCluster(cluster);
193
194 // Combine into the total covariance matrix from the ECL cluster (0..2) and the IP(3..5) as two 3x3 block matrices.
195 TMatrixDSym covmatcombined(6);
196 for (int i = 0; i < 3; i++) {
197 for (int j = 0; j <= i; j++) {
198 covmatcombined(i, j) = covmatcombined(j, i) = covmatecl(i, j);
199 covmatcombined(i + 3, j + 3) = covmatcombined(j + 3, i + 3) = covmatvertex(i, j);
200 }
201 }
202
203 TMatrixDSym covmatCart(4);
204 covmatCart = covmatcombined.Similarity(jacobiMatrix);
205 return covmatCart;
206}
Belle2::ClusterUtils::GetCovarianceMatrix3x3FromCluster
const TMatrixDSym GetCovarianceMatrix3x3FromCluster(const ECLCluster *cluster, int particleHypo=Const::photon.getPDGCode())
Returns 3x3 covariance matrix (E, theta, phi)
Definition: ClusterUtils.cc:134

◆ GetCovarianceMatrix7x7FromCluster() [1/2]

const TMatrixDSym GetCovarianceMatrix7x7FromCluster ( const ECLCluster *  cluster,
const TMatrixD &  jacobiMatrix 
)

Returns 7x7 covariance matrix (px, py, pz, E, x, y, z)

Returns
const TMatrixDSym

Definition at line 210 of file ClusterUtils.cc.

211{
212
213 return GetCovarianceMatrix7x7FromCluster(cluster, GetIPPositionCovarianceMatrix(), jacobiMatrix);
214}
Belle2::ClusterUtils::GetCovarianceMatrix7x7FromCluster
const TMatrixDSym GetCovarianceMatrix7x7FromCluster(const ECLCluster *cluster, const TMatrixD &jacobiMatrix)
Returns 7x7 covariance matrix (px, py, pz, E, x, y, z)
Definition: ClusterUtils.cc:210

◆ GetCovarianceMatrix7x7FromCluster() [2/2]

const TMatrixDSym GetCovarianceMatrix7x7FromCluster ( const ECLCluster *  cluster,
const TMatrixDSym &  covmatvertex,
const TMatrixD &  jacobiMatrix 
)

Returns 7x7 covariance matrix (px, py, pz, E, x, y, z)

Returns
const TMatrixDSym

Definition at line 216 of file ClusterUtils.cc.

218{
219 TMatrixDSym covmat4x4 = GetCovarianceMatrix4x4FromCluster(cluster, covmatvertex, jacobiMatrix);
220
221 TMatrixDSym covmatCart(7);
222
223 // px, py, pz, E
224 for (int i = 0; i < 4; i++) {
225 for (int j = 0; j <= i; j++) {
226 covmatCart(i, j) = covmatCart(j, i) = covmat4x4(i, j);
227 }
228 }
229
230 // x, y, z
231 for (int i = 0; i < 3; i++) {
232 for (int j = 0; j <= i; j++) {
233 covmatCart(i + 4, j + 4) = covmatCart(j + 4, i + 4) = covmatvertex(i, j);
234 }
235 }
236
237 return covmatCart;
238}

◆ GetIPPosition()

const XYZVector GetIPPosition ( )

Returns default IP position from beam parameters.

Returns
const XYZVector

Definition at line 241 of file ClusterUtils.cc.

242{
243 if (!m_beamSpotDB) {
244 B2WARNING("Beamspot not available, using (0, 0, 0) as IP position instead.");
245 return XYZVector(0.0, 0.0, 0.0);
246 } else
247 return XYZVector(m_beamSpotDB->getIPPosition().X(), m_beamSpotDB->getIPPosition().Y(), m_beamSpotDB->getIPPosition().Z());
248}
Belle2::ClusterUtils::m_beamSpotDB
DBObjPtr< BeamSpot > m_beamSpotDB
Beam spot database object.
Definition: ClusterUtils.h:127

◆ GetIPPositionCovarianceMatrix()

const TMatrixDSym GetIPPositionCovarianceMatrix ( )

Returns default IP position covariance matrix from beam parameters.

Returns
const TMatrixDSym

Definition at line 251 of file ClusterUtils.cc.

252{
253 if (!m_beamSpotDB) {
254 B2WARNING("Beam parameters not available, using ((1, 0, 0), (0, 1, 0), (0, 0, 1)) as IP covariance matrix instead.");
255
256 TMatrixDSym covmat(3);
257 for (int i = 0; i < 3; ++i) {
258 covmat(i, i) = 1.0; // 1.0*1.0 cm^2
259 }
260 return covmat;
261 } else
262 return m_beamSpotDB->getCovVertex();
263}

◆ GetJacobiMatrix4x6FromCluster() [1/2]

const TMatrixD GetJacobiMatrix4x6FromCluster ( const ECLCluster *  cluster,
const ROOT::Math::XYZVector &  vertex,
ECLCluster::EHypothesisBit  hypo 
)

Returns 4x6 Jacobi matrix (px, py, pz, E)

Returns
const TMatrixD

Definition at line 60 of file ClusterUtils.cc.

62{
63
64 // Calculate the Jacobi matrix J = dpx/dE dpx/dphi dpx/dtheta dpx/dx dpy/dy dpz/dz
65 // ...
66 // dpx/dE dE/dphi dE/dtheta dpx/dx dE/dy dE/dz
67 TMatrixD jacobian(4, 6);
68
69 const double R = cluster->getR();
70 const double energy = cluster->getEnergy(hypo);
71 const double theta = cluster->getTheta();
72 const double phi = cluster->getPhi();
73
74 const double st = sin(theta);
75 const double ct = cos(theta);
76 const double sp = sin(phi);
77 const double cp = cos(phi);
78
79 const double clx = R * st * cp; // cluster position x
80 const double cly = R * st * sp; // cluster position y
81 const double clz = R * ct; // cluster position z
82
83 const double vx = vertex.X(); // vertex position x
84 const double vy = vertex.Y(); // vertex position y
85 const double vz = vertex.Z(); // vertex position z
86
87 const double dx = clx - vx; // direction vector x
88 const double dy = cly - vy; // direction vector y
89 const double dz = clz - vz; // direction vector z
90 const double dx2 = dx * dx; // direction vector x squared
91 const double dy2 = dy * dy; // direction vector y squared
92 const double dz2 = dz * dz; // direction vector z squared
93
94 const double r2 = (dx * dx + dy * dy + dz * dz);
95 const double r12 = sqrt(r2);
96 const double r32 = pow(r2, 1.5);
97
98 // px = E * dx/r
99 jacobian(0, 0) = dx / r12; // dpx/dE
100 jacobian(0, 1) = -energy * R * ((dx * dy * cp) + ((dy2 + dz2) * sp)) * st / (r32); // dpx/dphi
101 jacobian(0, 2) = energy * R * (((dy2 + dz2) * cp * ct) - (dx * dy * ct * sp) + (dx * dz * st)) / (r32); // dpx/dtheta
102 jacobian(0, 3) = -energy * (dy2 + dz2) / (r32); // dpx/dvx
103 jacobian(0, 4) = energy * dx * dy / (r32); // dpx/dvy
104 jacobian(0, 5) = energy * dx * dz / (r32); // dpx/dvz
105
106 // py = E * dy/r
107 jacobian(1, 0) = dy / r12; // dpy/dE
108 jacobian(1, 1) = energy * R * (((dx2 + dz2) * cp) + (dx * dy * sp)) * st / (r32); // dpy/dphi
109 jacobian(1, 2) = energy * R * ((-dx * dy * cp * ct) + ((dx2 + dz2) * ct * sp) + (dy * dz * st)) / (r32); // dpz/dtheta
110 jacobian(1, 3) = energy * dx * dy / (r32); // dpy/dvx
111 jacobian(1, 4) = -energy * (dx2 + dz2) / (r32); // dpy/dvy
112 jacobian(1, 5) = energy * dy * dz / (r32); // dpy/dvz
113
114 // pz = E * dz/r
115 jacobian(2, 0) = dz / r12; // dpz/dE
116 jacobian(2, 1) = energy * R * dz * (-dy * cp + dx * sp) * st / (r32); // dpz/dphi
117 jacobian(2, 2) = -energy * R * ((dx * dz * cp * ct) + (dy * dz * ct * sp) + (dx2 + dy2) * st) / (r32); // dpz/dtheta
118 jacobian(2, 3) = energy * dx * dz / (r32); // dpz/dvx
119 jacobian(2, 4) = energy * dy * dz / (r32); // dpz/dvy
120 jacobian(2, 5) = -energy * (dx2 + dy2) / (r32); // dpz/ydvz
121
122 // E
123 jacobian(3, 0) = 1.0; // dE/dE
124 jacobian(3, 1) = 0.0; // dE/dphi
125 jacobian(3, 2) = 0.0; // dE/dtheta
126 jacobian(3, 3) = 0.0; // dE/dvx
127 jacobian(3, 4) = 0.0; // dE/dvy
128 jacobian(3, 5) = 0.0; // dE/dvz
129
130 // jacobian.Print();
131 return jacobian;
132}

◆ GetJacobiMatrix4x6FromCluster() [2/2]

const TMatrixD GetJacobiMatrix4x6FromCluster ( const ECLCluster *  cluster,
ECLCluster::EHypothesisBit  hypo 
)

Returns 4x6 Jacobi matrix (px, py, pz, E)

Returns
const TMatrixD

Definition at line 54 of file ClusterUtils.cc.

55{
56
57 return GetJacobiMatrix4x6FromCluster(cluster, GetIPPosition(), hypo);
58}
Belle2::ClusterUtils::GetJacobiMatrix4x6FromCluster
const TMatrixD GetJacobiMatrix4x6FromCluster(const ECLCluster *cluster, ECLCluster::EHypothesisBit hypo)
Returns 4x6 Jacobi matrix (px, py, pz, E)
Definition: ClusterUtils.cc:54

Member Data Documentation

◆ m_antiNeutronPositionResolutionDB

OptionalDBObjPtr<ECLPhotonEnergyResolution> m_antiNeutronPositionResolutionDB {"antiNeutronPositionResolutionDB"}
private

Antineutron position resolution database objects.

Definition at line 142 of file ClusterUtils.h.

◆ m_beamSpotDB

DBObjPtr<BeamSpot> m_beamSpotDB
private

Beam spot database object.

Definition at line 127 of file ClusterUtils.h.

◆ m_kaonPositionResolutionDB

OptionalDBObjPtr<ECLPhotonEnergyResolution> m_kaonPositionResolutionDB {"kaonPositionResolutionDB"}
private

Neutral kaon position resolution database objects.

Definition at line 147 of file ClusterUtils.h.

◆ m_neutronPositionResolutionDB

OptionalDBObjPtr<ECLPhotonEnergyResolution> m_neutronPositionResolutionDB {"neutronPositionResolutionDB"}
private

Neutron position resolution database objects.

Definition at line 137 of file ClusterUtils.h.

◆ m_photonEnergyResolutionDB

OptionalDBObjPtr<ECLPhotonEnergyResolution> m_photonEnergyResolutionDB
private

Photon energy resolution database object.

Definition at line 132 of file ClusterUtils.h.

The documentation for this class was generated from the following files: