Belle II Software light-2406-ragdoll
MCInitialParticles.h
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
9#pragma once
10
11#include <framework/gearbox/Const.h>
12#include <framework/utilities/LabToCms.h>
13
14#include <TVector3.h>
15#include <Math/Boost.h>
16#include <Math/LorentzRotation.h>
17#include <Math/Vector3D.h>
18#include <Math/Vector4D.h>
19
20namespace Belle2 {
31 class MCInitialParticles: public TObject {
32
33 public:
34
38 c_generateCMS = 1 << 0,
46 c_smearVertex = 1 << 3,
49 };
50
52 MCInitialParticles(): TObject() {}
53
57
60 {
61 m_her = b.m_her; m_ler = b.m_ler; m_vertex = b.m_vertex;
62 m_validFlag = b.m_validFlag; m_generationFlags = b.m_generationFlags;
63 resetBoost();
64 return *this;
65 }
66
68 bool operator==(const MCInitialParticles& b) const
69 {
70 // FIXME: sin(x) returns slightly different values on
71 // different platforms in some cases so we cannot just do an equality
72 // comparison. We need to do this more elegantly, this is just for
73 // testing if it solves all problems
74#if defined(MCP_DBL_CMP) || defined(MCP_VEC3_CMP) || defined(MCP_VEC4_CMP)
75#error Macro already defined, cannot continue
76#endif
77#define MCP_DBL_CMP(a,b,x) ((a.X()==b.X())||(std::abs(a.X()-b.X())<1e-10))
78#define MCP_VEC3_CMP(a,b) (MCP_DBL_CMP(a,b,X) && MCP_DBL_CMP(a,b,Y) && MCP_DBL_CMP(a,b,Z))
79#define MCP_VEC4_CMP(a,b) (MCP_VEC3_CMP(a,b) && MCP_DBL_CMP(a,b,E))
80 return MCP_VEC4_CMP(m_her, b.m_her) && MCP_VEC4_CMP(m_ler, b.m_ler) && MCP_VEC3_CMP(m_vertex, b.m_vertex)
81 && m_validFlag == b.m_validFlag &&
82 m_generationFlags == b.m_generationFlags;
83#undef MCP_DBL_CMP
84#undef MCP_VEC3_CMP
85#undef MCP_VEC4_CMP
86 }
87
90
97 void set(const ROOT::Math::PxPyPzEVector& her, const ROOT::Math::PxPyPzEVector& ler, const ROOT::Math::XYZVector& vertex)
98 {
99 m_her = her;
100 m_ler = ler;
101 m_vertex = vertex;
102 m_validFlag = true;
103 resetBoost();
104 }
105
116 void setByLorentzTransformation(double Ecms, double bX, double bY, double bZ, double angleXZ, double angleYZ,
117 const ROOT::Math::XYZVector& vertex)
118 {
119 if (m_labToCMS) delete m_labToCMS;
120 if (m_CMSToLab) delete m_CMSToLab;
121
122 m_invariantMass = Ecms;
123 m_CMSToLab = new ROOT::Math::LorentzRotation();
124 m_labToCMS = new ROOT::Math::LorentzRotation();
125 *m_CMSToLab = cmsToLab(bX, bY, bZ, angleXZ, angleYZ);
126 *m_labToCMS = m_CMSToLab->Inverse();
127
128 const double me = Const::electron.getMass();
129 double p = sqrt(Ecms * Ecms / 4 - me * me);
130 m_her = (*m_CMSToLab) * ROOT::Math::PxPyPzEVector(0.0, 0.0, p, Ecms / 2);
131 m_ler = (*m_CMSToLab) * ROOT::Math::PxPyPzEVector(0.0, 0.0, -p, Ecms / 2);
132
133 m_vertex = vertex;
134 m_validFlag = true;
135 }
136
138 void setHER(const ROOT::Math::PxPyPzEVector& her)
139 {
140 m_her = her;
141 resetBoost();
142 }
143
145 void setLER(const ROOT::Math::PxPyPzEVector& ler)
146 {
147 m_ler = ler;
148 resetBoost();
149 }
150
152 void setVertex(const ROOT::Math::XYZVector& vertex)
153 {
154 m_vertex = vertex;
155 }
156
158 void setTime(double time) {m_time = time;}
159
161 virtual void setGenerationFlags(int flags) { m_generationFlags = flags; }
162
164 const ROOT::Math::PxPyPzEVector& getHER() const { return m_her; }
165
167 const ROOT::Math::PxPyPzEVector& getLER() const { return m_ler; }
168
170 const ROOT::Math::XYZVector& getVertex() const { return m_vertex; }
171
173 double getTime() const {return m_time;}
174
176 double getEnergy() const { return (m_her + m_ler).E(); }
177
179 double getMass() const { calculateBoost(); return m_invariantMass; }
180
182 ROOT::Math::XYZVector getBoostVector() const { calculateBoost(); return -(m_her + m_ler).BoostToCM(); }
183
185 ROOT::Math::PxPyPzEVector getBoostedHER() const { calculateBoost(); return m_boostedHER; }
186
188 const ROOT::Math::LorentzRotation& getLabToCMS() const
189 {
190 calculateBoost(); return *m_labToCMS;
191 }
192
194 const ROOT::Math::LorentzRotation& getCMSToLab() const
195 {
196 calculateBoost(); return *m_CMSToLab;
197 }
198
200 bool getValidFlag() const { return m_validFlag; }
201
203 int getGenerationFlags() const { return m_generationFlags; }
204
206 bool hasGenerationFlags(int flags) const { return (m_generationFlags & flags) == flags; }
207
210 std::string getGenerationFlagString(const std::string& separator = " ") const;
211
212
220 static ROOT::Math::LorentzRotation cmsToLab(double bX, double bY, double bZ, double angleXZ, double angleYZ);
221
222 private:
223
225 void calculateBoost() const;
227 void resetBoost();
229 ROOT::Math::PxPyPzEVector m_her;
231 ROOT::Math::PxPyPzEVector m_ler;
233 ROOT::Math::XYZVector m_vertex;
235 double m_time = 0;
237 mutable ROOT::Math::LorentzRotation* m_labToCMS{nullptr};
239 mutable ROOT::Math::LorentzRotation* m_CMSToLab{nullptr};
241 mutable double m_invariantMass{0.0};
243 mutable ROOT::Math::PxPyPzEVector m_boostedHER;
245 bool m_validFlag = false;
246
247 protected:
248
251
252 private:
253
256 };
257
259 {
260 if (m_labToCMS)
261 return;
262
263 ROOT::Math::PxPyPzEVector beam = m_her + m_ler;
264 // Save the invariant mass because it's used very often in analysis
265 m_invariantMass = beam.M();
266
267 // If we generate events in CMS we already are in CMS and there is no
268 // transformation so let's use the identity
270 m_labToCMS = new ROOT::Math::LorentzRotation();
271 m_CMSToLab = new ROOT::Math::LorentzRotation();
272 return;
273 }
274
275 m_boostedHER = ROOT::Math::LorentzRotation(ROOT::Math::Boost(beam.BoostToCM())) * m_her;
276 double cmsAngleXZ = atan(m_boostedHER.X() / m_boostedHER.Z());
277 double cmsAngleYZ = atan(m_boostedHER.Y() / m_boostedHER.Z());
278 m_labToCMS = new ROOT::Math::LorentzRotation(
279 LabToCms::rotateLabToCms(-beam.BoostToCM(), cmsAngleXZ, cmsAngleYZ)
280 );
281
282 //cache derived quantities
283 m_CMSToLab = new ROOT::Math::LorentzRotation(m_labToCMS->Inverse());
284 }
285
286
287
288
289
291 {
292 delete m_labToCMS;
293 delete m_CMSToLab;
294 m_labToCMS = nullptr;
295 m_CMSToLab = nullptr;
296 m_invariantMass = 0.0;
297 m_boostedHER = ROOT::Math::PxPyPzEVector();
298 }
299
301} //Belle2 namespace
double getMass() const
Particle mass.
Definition: UnitConst.cc:356
static const ChargedStable electron
electron particle
Definition: Const.h:659
static ROOT::Math::LorentzRotation rotateLabToCms(const ROOT::Math::XYZVector &boostVector, double cmsAngleXZ, double cmsAngleYZ)
Function takes 3D boostVector and angles of the HER momentum in the CM system obtained by pure boost.
Definition: LabToCms.h:43
This class contains the initial state for the given event.
int m_generationFlags
Flags to be used when generating events.
const ROOT::Math::PxPyPzEVector & getHER() const
Get 4vector of the high energy beam.
ROOT::Math::LorentzRotation * m_CMSToLab
transient
bool operator==(const MCInitialParticles &b) const
Equality operator.
int getGenerationFlags() const
Get the generation flags to be used for event generation (ORed combination of EGenerationFlags)
bool getValidFlag() const
Get the flag to check if a valid MCInitialParticles object was already generated and filled in an eve...
ROOT::Math::PxPyPzEVector m_boostedHER
transient
ROOT::Math::PxPyPzEVector getBoostedHER() const
Get the 4-vector of electron beam in CM system obtained by pure boost.
void setVertex(const ROOT::Math::XYZVector &vertex)
Set the vertex position.
double m_time
collision time
const ROOT::Math::PxPyPzEVector & getLER() const
Get 4vector of the low energy beam.
ROOT::Math::PxPyPzEVector m_ler
LER 4vector.
void setTime(double time)
Set collision time.
double getEnergy() const
Get the actual collision energy (in lab system)
ROOT::Math::PxPyPzEVector m_her
HER 4vector.
EGenerationFlags
Possible Flags for initial event generation.
@ c_smearBeam
smear the full beam momentum (energy and direction)
@ c_generateCMS
generate initial event in CMS instead of lab
@ c_smearBeamEnergy
smear energy of HER and LER (but not direction)
@ c_smearBeamDirection
smear direction of HER and LER (but not energy)
ROOT::Math::LorentzRotation * m_labToCMS
Boost from Lab into CMS.
const ROOT::Math::LorentzRotation & getLabToCMS() const
Return the LorentzRotation to convert from lab to CMS frame.
ROOT::Math::XYZVector m_vertex
collision position
const ROOT::Math::LorentzRotation & getCMSToLab() const
Return the LorentzRotation to convert from CMS to lab frame.
std::string getGenerationFlagString(const std::string &separator=" ") const
Return string representation of all active flags for printing.
MCInitialParticles & operator=(const MCInitialParticles &b)
Assignment operator.
virtual void setGenerationFlags(int flags)
Set the generation flags to be used for event generation (ORed combination of EGenerationFlags)
static ROOT::Math::LorentzRotation cmsToLab(double bX, double bY, double bZ, double angleXZ, double angleYZ)
Return the LorentzRotation from CMS to LAB based on the following parameters.
MCInitialParticles()
Default constructor.
void setByLorentzTransformation(double Ecms, double bX, double bY, double bZ, double angleXZ, double angleYZ, const ROOT::Math::XYZVector &vertex)
Initialize the event values from CMS energy and parameters of the Lorentz transformation between LAB ...
bool hasGenerationFlags(int flags) const
Check if a certain set of EGenerationFlags is set.
const ROOT::Math::XYZVector & getVertex() const
Get the position of the collision.
void setHER(const ROOT::Math::PxPyPzEVector &her)
Set the High Energy Beam 4-momentum.
MCInitialParticles(const MCInitialParticles &b)
Copy constructor.
void setLER(const ROOT::Math::PxPyPzEVector &ler)
Set the Low Energy Beam 4-momentum.
virtual ~MCInitialParticles()
Free memory of the LorentzRotation if it was created.
ROOT::Math::XYZVector getBoostVector() const
Get the boost vector (velocity of system produced in the collision)
double getMass() const
Get the invariant mass of the collision (= energy in CMS)
double getTime() const
Get collision time.
void set(const ROOT::Math::PxPyPzEVector &her, const ROOT::Math::PxPyPzEVector &ler, const ROOT::Math::XYZVector &vertex)
Set the initial event values, i.e.
ClassDef(MCInitialParticles, 5)
ROOT Dictionary.
void resetBoost()
Reset cached transformations after changing parameters.
void calculateBoost() const
Calculate the Lorentz transformations LAB->CMS & CMS->LAB if necessary.
Abstract base class for different kinds of events.
Definition: ClusterUtils.h:24