BeamParameters Class Reference

This class contains the nominal beam parameters and the parameters used for smearing of the primary vertex and the beam energy and momentum. More...

#include <BeamParameters.h>

Inheritance diagram for BeamParameters:

Public Types
enum	EGenerationFlags {   c_generateCMS = 1 << 0 ,   c_smearBeamEnergy = 1 << 1 ,   c_smearBeamDirection = 1 << 2 ,   c_smearBeam = c_smearBeamEnergy | c_smearBeamDirection ,   c_smearVertex = 1 << 3 ,   c_smearALL = c_smearVertex | c_smearBeam }
	Possible Flags for initial event generation. More...

Public Member Functions
	BeamParameters ()
	Default constructor.
	BeamParameters (const BeamParameters &b)
	Copy constructor.
BeamParameters &	operator= (const BeamParameters &b)
	Assignment operator.
bool	operator== (const BeamParameters &b) const
	Equality operator.
void	setGenerationFlags (int flags) override
	Set the generation flags to be used for event generation (ORed combination of EGenerationFlags).
void	setCovHER (const TMatrixDSym &cov)
	Set the covariance matrix for HER (E, theta_x, theta_y) where E is the energy, theta_x is the horizontal angle between nominal direction and actual direction in spread and theta_y is the vertical angle The upper triangle will be saved.
void	setCovLER (const TMatrixDSym &cov)
	Set the covariance matrix for LER (E, theta_x, theta_y) where E is the energy, theta_x is the horizontal angle between nominal direction and actual direction in spread and theta_y is the vertical angle.
void	setCovVertex (const TMatrixDSym &cov)
	Set the covariance matrix of the vertex position.
void	setHER (double energy, double angleX, double angleY, const std::vector< double > &cov)
	Set the HER FourVector and error matrix from beam energy, angle and covariance entries.
void	setLER (double energy, double angleX, double angleY, const std::vector< double > &cov)
	Set the LER FourVector and error matrix from beam energy, angle and covariance entries.
void	setVertex (const ROOT::Math::XYZVector &vertex, const std::vector< double > &cov)
	Set the vertex position and error matrix.
TMatrixDSym	getCovHER () const
	Get the covariance matrix of HER (E, theta_x, theta_y) where E is the energy, theta_x is the horizontal angle between nominal direction and actual direction in spread and theta_y is the vertical angle.
TMatrixDSym	getCovLER () const
	Get the covariance matrix of LER (E, theta_x, theta_y) where E is the energy, theta_x is the horizontal angle between nominal direction and actual direction in spread and theta_y is the vertical angle.
TMatrixDSym	getCovVertex () const
	Get the covariance matrix of the vertex position.
void	setLER (const ROOT::Math::PxPyPzEVector &ler)
	Set the Low Energy Beam 4-momentum.
void	setHER (const ROOT::Math::PxPyPzEVector &her)
	Set the High Energy Beam 4-momentum.
void	setVertex (const ROOT::Math::XYZVector &vertex)
	Set the vertex position.
bool	operator== (const MCInitialParticles &b) const
	Equality operator.
void	set (const ROOT::Math::PxPyPzEVector &her, const ROOT::Math::PxPyPzEVector &ler, const ROOT::Math::XYZVector &vertex)
	Set the initial event values, i.e.
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 and CMS.
void	setTime (double time)
	Set collision time.
const ROOT::Math::PxPyPzEVector &	getHER () const
	Get 4vector of the high energy beam.
const ROOT::Math::PxPyPzEVector &	getLER () const
	Get 4vector of the low energy beam.
const ROOT::Math::XYZVector &	getVertex () const
	Get the position of the collision.
double	getTime () const
	Get collision time.
double	getEnergy () const
	Get the actual collision energy (in lab system)
double	getMass () const
	Get the invariant mass of the collision (= energy in CMS)
ROOT::Math::XYZVector	getBoostVector () const
	Get the boost vector (velocity of system produced in the collision)
ROOT::Math::PxPyPzEVector	getBoostedHER () const
	Get the 4-vector of electron beam in CM system obtained by pure boost.
const ROOT::Math::LorentzRotation &	getLabToCMS () const
	Return the LorentzRotation to convert from lab to CMS frame.
const ROOT::Math::LorentzRotation &	getCMSToLab () const
	Return the LorentzRotation to convert from CMS to lab frame.
bool	getValidFlag () const
	Get the flag to check if a valid MCInitialParticles object was already generated and filled in an event.
int	getGenerationFlags () const
	Get the generation flags to be used for event generation (ORed combination of EGenerationFlags)
bool	hasGenerationFlags (int flags) const
	Check if a certain set of EGenerationFlags is set.
std::string	getGenerationFlagString (const std::string &separator=" ") const
	Return string representation of all active flags for printing.

Static Public Member Functions
static ROOT::Math::PxPyPzEVector	getFourVector (double energy, double angleX, double angleY, bool isHER)
	Calculate FourVector of a beam from energy and angles in xz and yz planes.
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.

Protected Attributes
int	m_generationFlags {0}
	Flags to be used when generating events.

Private Member Functions
	ClassDefOverride (BeamParameters, 3)
	ClassDef.
void	calculateBoost () const
	Calculate the Lorentz transformations LAB->CMS & CMS->LAB if necessary.
void	resetBoost ()
	Reset cached transformations after changing parameters.
	ClassDef (MCInitialParticles, 5)
	ROOT Dictionary.

Static Private Member Functions
static void	setCovMatrix (Double32_t *member, const std::vector< double > &cov, bool common)
	Set covariance matrix from vector of entries.
static void	setCovMatrix (Double32_t *member, const TMatrixDSym &cov)
	Set covariance matrix from ROOT Matrix object.
static TMatrixDSym	getCovMatrix (const Double32_t *member)
	Obtain covariance matrix from a given float array.

Private Attributes
Double32_t	m_covHER [6]
	Covariance matrix of the high energy beam at the IP.
Double32_t	m_covLER [6]
	Covariance matrix of the low energy beam at the IP.
Double32_t	m_covVertex [6]
	Covariance matrix of the vertex position.
ROOT::Math::PxPyPzEVector	m_her
	HER 4vector.
ROOT::Math::PxPyPzEVector	m_ler
	LER 4vector.
ROOT::Math::XYZVector	m_vertex
	collision position
double	m_time = 0
	collision time
ROOT::Math::LorentzRotation *	m_labToCMS {nullptr}
	Boost from Lab into CMS.
ROOT::Math::LorentzRotation *	m_CMSToLab {nullptr}
	transient
double	m_invariantMass {0.0}
	transient
ROOT::Math::PxPyPzEVector	m_boostedHER
	transient
bool	m_validFlag = false
	transient

Detailed Description

This class contains the nominal beam parameters and the parameters used for smearing of the primary vertex and the beam energy and momentum.

It is event independent (but might be run or even sub run dependent)

Definition at line 25 of file BeamParameters.h.

Member Enumeration Documentation

EGenerationFlags

enum EGenerationFlags

inherited

Possible Flags for initial event generation.

Enumerator
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)
c_smearBeam	smear the full beam momentum (energy and direction)
c_smearVertex	smear vertex
c_smearALL	smear all

Definition at line 35 of file MCInitialParticles.h.

                          {
      c_generateCMS = 1 << 0,
      c_smearBeamEnergy = 1 << 1,
      c_smearBeamDirection = 1 << 2,
      c_smearBeam = c_smearBeamEnergy | c_smearBeamDirection,
      c_smearVertex = 1 << 3,
      c_smearALL = c_smearVertex | c_smearBeam,
    };

Constructor & Destructor Documentation

BeamParameters() [1/2]

BeamParameters ( )

inline

Default constructor.

Definition at line 34 of file BeamParameters.h.

                    : MCInitialParticles(), m_covHER{0}, m_covLER{0}, m_covVertex{0}
    {
      // 14 means all the smearings turned on
      m_generationFlags = 14;
    }

BeamParameters() [2/2]

BeamParameters ( const BeamParameters &  b )

inline

Copy constructor.

Definition at line 41 of file BeamParameters.h.

                                           : MCInitialParticles(b)
    {
      std::copy_n(b.m_covHER, 6, m_covHER);
      std::copy_n(b.m_covLER, 6, m_covLER);
      std::copy_n(b.m_covVertex, 6, m_covVertex);
    }

Member Function Documentation

cmsToLab()

ROOT::Math::LorentzRotation cmsToLab ( double  bX, double  bY, double  bZ, double  angleXZ, double  angleYZ  )

staticinherited

Return the LorentzRotation from CMS to LAB based on the following parameters.

Parameters

bX	x-component of the boost vector, i.e. of (pHER + pLER) / (eHER + eLER), where pHER & pLER are momentum 3-vectors
bY	y-component of the boost vector, i.e. of (pHER + pLER) / (eHER + eLER), where pHER & pLER are momentum 3-vectors
bZ	z-component of the boost vector, i.e. of (pHER + pLER) / (eHER + eLER), where pHER & pLER are momentum 3-vectors
angleXZ	angle in the XZ plane of the collision axis in the CM system obtained by pure boost
angleYZ	angle in the YZ plane of the collision axis in the CM system obtained by pure boost

Definition at line 31 of file MCInitialParticles.cc.

{
  //boost to CM frame
  ROOT::Math::LorentzRotation boost(ROOT::Math::Boost(-1.*ROOT::Math::XYZVector(bX, bY, bZ)));
 
 
  //rotation such that the collision axis is aligned with z-axis
  ROOT::Math::XYZVector zaxis(0., 0., 1.); //target collision axis
 
  double tanAngleXZ = tan(angleXZ);
  double tanAngleYZ = tan(angleYZ);
  double Norm   = 1 / sqrt(1 + pow(tanAngleXZ, 2) + pow(tanAngleYZ, 2));
  ROOT::Math::XYZVector electronCMS(Norm * tanAngleXZ, Norm * tanAngleYZ, Norm); //current collision axis
 
  ROOT::Math::XYZVector rotAxis = zaxis.Cross(electronCMS);
  double rotangle = asin(rotAxis.R());
 
  ROOT::Math::LorentzRotation rotation(ROOT::Math::AxisAngle(rotAxis, -rotangle));
 
 
  ROOT::Math::LorentzRotation trans  = rotation * boost;
  ROOT::Math::LorentzRotation transI = trans.Inverse();
  return transI;
}

getBoostedHER()

ROOT::Math::PxPyPzEVector getBoostedHER ( ) const

inlineinherited

Get the 4-vector of electron beam in CM system obtained by pure boost.

Definition at line 184 of file MCInitialParticles.h.

{ calculateBoost(); return m_boostedHER; }

getBoostVector()

ROOT::Math::XYZVector getBoostVector ( ) const

inlineinherited

Get the boost vector (velocity of system produced in the collision)

Definition at line 181 of file MCInitialParticles.h.

{ calculateBoost(); return -(m_her + m_ler).BoostToCM(); }

getCMSToLab()

const ROOT::Math::LorentzRotation & getCMSToLab ( ) const

inlineinherited

Return the LorentzRotation to convert from CMS to lab frame.

Definition at line 193 of file MCInitialParticles.h.

    {
      calculateBoost(); return *m_CMSToLab;
    }

getCovHER()

TMatrixDSym getCovHER ( ) const

inline

Get the covariance matrix of HER (E, theta_x, theta_y) where E is the energy, theta_x is the horizontal angle between nominal direction and actual direction in spread and theta_y is the vertical angle.

Definition at line 157 of file BeamParameters.h.

{ return getCovMatrix(m_covHER); }

getCovLER()

TMatrixDSym getCovLER ( ) const

inline

Get the covariance matrix of LER (E, theta_x, theta_y) where E is the energy, theta_x is the horizontal angle between nominal direction and actual direction in spread and theta_y is the vertical angle.

Definition at line 162 of file BeamParameters.h.

{ return getCovMatrix(m_covLER); }

getCovVertex()

TMatrixDSym getCovVertex ( ) const

inline

Get the covariance matrix of the vertex position.

Definition at line 165 of file BeamParameters.h.

{ return getCovMatrix(m_covVertex); }

getEnergy()

double getEnergy ( ) const

inlineinherited

Get the actual collision energy (in lab system)

Definition at line 175 of file MCInitialParticles.h.

{ return (m_her + m_ler).E(); }

getFourVector()

static ROOT::Math::PxPyPzEVector getFourVector ( double  energy, double  angleX, double  angleY, bool  isHER  )

static

Calculate FourVector of a beam from energy and angles in xz and yz planes.

if isHER=true, the angles are measured wrt +p if isHER=false, the angles are measured wrt -p, as is the standard convention for LER

Parameters

energy	beam energy
angleX	horizontal angle wrt z-axis, i.e. angle measured in xz plane
angleY	vertical angle wrt z-axis, i.e. angle measured in yz plane
isHER	isHER=true for HER, isHER=false for LER

getGenerationFlags()

int getGenerationFlags ( ) const

inlineinherited

Get the generation flags to be used for event generation (ORed combination of EGenerationFlags)

Definition at line 202 of file MCInitialParticles.h.

{ return m_generationFlags; }

getGenerationFlagString()

std::string getGenerationFlagString ( const std::string &  separator = " " ) const

inherited

Return string representation of all active flags for printing.

Parameters

separator

separation string to be put between flags

Definition at line 13 of file MCInitialParticles.cc.

{
  std::string flags = "";
  const std::vector<std::pair<int, std::string>> flagvalues{
    {c_generateCMS, "generateCMS"},
    {c_smearBeamEnergy, "smearBeamEnergy"},
    {c_smearBeamDirection, "smearBeamDirection"},
    {c_smearVertex, "smearVertex"}
  };
  for (auto& i : flagvalues) {
    if (hasGenerationFlags(i.first)) {
      if (flags.size() > 0) flags += separator;
      flags += i.second;
    }
  }
  return flags;
}

getHER()

const ROOT::Math::PxPyPzEVector & getHER ( ) const

inlineinherited

Get 4vector of the high energy beam.

Definition at line 163 of file MCInitialParticles.h.

{ return m_her; }

getLabToCMS()

const ROOT::Math::LorentzRotation & getLabToCMS ( ) const

inlineinherited

Return the LorentzRotation to convert from lab to CMS frame.

Definition at line 187 of file MCInitialParticles.h.

    {
      calculateBoost(); return *m_labToCMS;
    }

getLER()

const ROOT::Math::PxPyPzEVector & getLER ( ) const

inlineinherited

Get 4vector of the low energy beam.

Definition at line 166 of file MCInitialParticles.h.

{ return m_ler; }

getMass()

double getMass ( ) const

inlineinherited

Get the invariant mass of the collision (= energy in CMS)

Definition at line 178 of file MCInitialParticles.h.

{ calculateBoost(); return m_invariantMass; }

getTime()

double getTime ( ) const

inlineinherited

Get collision time.

Definition at line 172 of file MCInitialParticles.h.

{return m_time;}

getValidFlag()

bool getValidFlag ( ) const

inlineinherited

Get the flag to check if a valid MCInitialParticles object was already generated and filled in an event.

Definition at line 199 of file MCInitialParticles.h.

{ return m_validFlag; }

getVertex()

const ROOT::Math::XYZVector & getVertex ( ) const

inlineinherited

Get the position of the collision.

Definition at line 169 of file MCInitialParticles.h.

{ return m_vertex; }

hasGenerationFlags()

bool hasGenerationFlags ( int  flags ) const

inlineinherited

Check if a certain set of EGenerationFlags is set.

Definition at line 205 of file MCInitialParticles.h.

{ return (m_generationFlags & flags) == flags; }

operator=()

BeamParameters & operator= ( const BeamParameters &  b )

inline

Assignment operator.

Definition at line 49 of file BeamParameters.h.

    {
      MCInitialParticles::operator=(b);
      std::copy_n(b.m_covHER, 6, m_covHER);
      std::copy_n(b.m_covLER, 6, m_covLER);
      std::copy_n(b.m_covVertex, 6, m_covVertex);
      return *this;
    }

operator==() [1/2]

bool operator== ( const BeamParameters &  b ) const

inline

Equality operator.

Definition at line 59 of file BeamParameters.h.

    {
      // since we only save the covariance matrices with float precision we
      // need to also do the comparison with float precision.
      auto floatcmp = [](double dbl_a, double dbl_b) { return (float)dbl_a == (float)dbl_b; };
      return MCInitialParticles::operator==(b) &&
             std::equal(m_covHER, m_covHER + 6, b.m_covHER, floatcmp) &&
             std::equal(m_covLER, m_covLER + 6, b.m_covLER, floatcmp) &&
             std::equal(m_covVertex, m_covVertex + 6, b.m_covVertex, floatcmp);
    }

operator==() [2/2]

bool operator== ( const MCInitialParticles &  b ) const

inlineinherited

Equality operator.

Definition at line 67 of file MCInitialParticles.h.

    {
      // FIXME: sin(x) returns slightly different values on
      // different platforms in some cases so we cannot just do an equality
      // comparison. We need to do this more elegantly, this is just for
      // testing if it solves all problems
#if defined(MCP_DBL_CMP) || defined(MCP_VEC3_CMP) || defined(MCP_VEC4_CMP)
#error Macro already defined, cannot continue
#endif
#define MCP_DBL_CMP(a,b,x) ((a.X()==b.X())||(std::abs(a.X()-b.X())<1e-10))
#define MCP_VEC3_CMP(a,b) (MCP_DBL_CMP(a,b,X) && MCP_DBL_CMP(a,b,Y) && MCP_DBL_CMP(a,b,Z))
#define MCP_VEC4_CMP(a,b) (MCP_VEC3_CMP(a,b) && MCP_DBL_CMP(a,b,E))
      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)
             && m_validFlag == b.m_validFlag &&
             m_generationFlags == b.m_generationFlags;
#undef MCP_DBL_CMP
#undef MCP_VEC3_CMP
#undef MCP_VEC4_CMP
    }

set()

void set ( const ROOT::Math::PxPyPzEVector &  her, const ROOT::Math::PxPyPzEVector &  ler, const ROOT::Math::XYZVector &  vertex  )

inlineinherited

Set the initial event values, i.e.

the four momenta of both beams and the vertex

Parameters

her	4vector of the high energy beam
ler	4vector of the low energy beam
vertex	position of the actual collision vertex

Definition at line 96 of file MCInitialParticles.h.

    {
      m_her = her;
      m_ler = ler;
      m_vertex = vertex;
      m_validFlag = true;
      resetBoost();
    }

setByLorentzTransformation()

void setByLorentzTransformation ( double  Ecms, double  bX, double  bY, double  bZ, double  angleXZ, double  angleYZ, const ROOT::Math::XYZVector &  vertex  )

inlineinherited

Initialize the event values from CMS energy and parameters of the Lorentz transformation between LAB and CMS.

In addition the vertex is also initialized.

Parameters

Ecms	centre-of-mass energy of the collision
bX	x-component of the boost vector, i.e. of (pHER + pLER) / (eHER + eLER), where pHER & pLER are momentum 3-vectors
bY	y-component of the boost vector, i.e. of (pHER + pLER) / (eHER + eLER), where pHER & pLER are momentum 3-vectors
bZ	z-component of the boost vector, i.e. of (pHER + pLER) / (eHER + eLER), where pHER & pLER are momentum 3-vectors
angleXZ	angle in the XZ plane of the collision axis in the CM system obtained by pure boost
angleYZ	angle in the YZ plane of the collision axis in the CM system obtained by pure boost
vertex	position of the actual collision vertex

Definition at line 115 of file MCInitialParticles.h.

    {
      if (m_labToCMS) delete m_labToCMS;
      if (m_CMSToLab) delete m_CMSToLab;
 
      m_invariantMass = Ecms;
      m_CMSToLab      = new ROOT::Math::LorentzRotation();
      m_labToCMS      = new ROOT::Math::LorentzRotation();
      *m_CMSToLab     = cmsToLab(bX, bY, bZ, angleXZ, angleYZ);
      *m_labToCMS     = m_CMSToLab->Inverse();
 
      const double me = Const::electron.getMass();
      double p = sqrt(Ecms * Ecms / 4 - me * me);
      m_her = (*m_CMSToLab) * ROOT::Math::PxPyPzEVector(0.0, 0.0,  p, Ecms / 2);
      m_ler = (*m_CMSToLab) * ROOT::Math::PxPyPzEVector(0.0, 0.0, -p, Ecms / 2);
 
      m_vertex = vertex;
      m_validFlag = true;
    }

setCovHER()

void setCovHER ( const TMatrixDSym &  cov )

inline

Set the covariance matrix for HER (E, theta_x, theta_y) where E is the energy, theta_x is the horizontal angle between nominal direction and actual direction in spread and theta_y is the vertical angle The upper triangle will be saved.

Definition at line 91 of file BeamParameters.h.

{ setCovMatrix(m_covHER, cov); }

setCovLER()

void setCovLER ( const TMatrixDSym &  cov )

inline

Set the covariance matrix for LER (E, theta_x, theta_y) where E is the energy, theta_x is the horizontal angle between nominal direction and actual direction in spread and theta_y is the vertical angle.

The upper triangle will be saved.

Definition at line 97 of file BeamParameters.h.

{ setCovMatrix(m_covLER, cov); }

setCovMatrix()

static void setCovMatrix ( Double32_t *  member, const std::vector< double > &  cov, bool  common  )

staticprivate

Set covariance matrix from vector of entries.

The vector for the covariance matrix can have either 0, 1, 3, 6 or 9 entries:

• 0 entries means no error.
• 1 entry will be treated as the common variance for all variables if common is true. Otherwise it will be taken as the variance of just the first element.
• 3 entries will be treated as uncorrelated variances for all variables (diagonal of the matrix)
• 6 entries will be interpreted as the upper triangle of the covariance matrix with the element order being (0, 0), (0, 1), (0, 2), (1, 1), (1, 2), (2, 2)
• 9 entries for the full covariance matrix in row-major order. The symmetry of the matrix will not be checked but just the lower triangle will be used.

Parameters

member	to the member which contains the matrix
cov	entries for the covariance matrix
common	if true a 1-element cov will be treated as the common variance for all diagonal elements

setCovVertex()

void setCovVertex ( const TMatrixDSym &  cov )

inline

Set the covariance matrix of the vertex position.

The upper triangle will be saved.

Definition at line 100 of file BeamParameters.h.

{ setCovMatrix(m_covVertex, cov); }

setGenerationFlags()

void setGenerationFlags ( int  flags )

inlineoverridevirtual

Set the generation flags to be used for event generation (ORed combination of EGenerationFlags).

The only difference w.r.t. MCInitialParticles::setGenerationFlags() is that a WARNING is thrown if a flag different from 14 (= all the smearings turned on) is set.

Reimplemented from MCInitialParticles.

Definition at line 74 of file BeamParameters.h.

    {
      if (flags != 14)
        B2WARNING(R"RAW(The generation flags are not set to the default value.
 
    The default value for the generation flags is 14: a different value means
    that some smearings (beam energy, vertex position, etc.) may be turned off.
 
    This is fine only for local tests or for special MC productions, but not
    for default MC productions.)RAW");
      m_generationFlags = flags;
    }

setHER() [1/2]

void setHER ( const ROOT::Math::PxPyPzEVector &  her )

inline

Set the High Energy Beam 4-momentum.

Definition at line 137 of file MCInitialParticles.h.

    {
      m_her = her;
      resetBoost();
    }

setHER() [2/2]

void setHER	(	double	energy,
		double	angleX,
		double	angleY,
		const std::vector< double > &	cov
	)

Set the HER FourVector and error matrix from beam energy, angle and covariance entries.

The vector for the covariance matrix can have either 0, 1, 3, 6 or 9 entries:

• 0 entries means no error.
• 1 entry will be treated as the variance of the beam energy.
• 3 entries will be treated as uncorrelated variances for all variables (diagonal of the matrix)
• 6 entries will be interpreted as the upper triangle of the covariance matrix with the element order being (0, 0), (0, 1), (0, 2), (1, 1), (1, 2), (2, 2)
• 9 entries for the full covariance matrix in row-major order. The symmetry of the matrix will not be checked but just the lower triangle will be used.

Parameters

energy	beam energy
angleX	angle between beam direction and z axis (in the x-z plane). Negative values are treated as M_PI - abs(angle)
angleY	angle between beam direction and z axis (in the y-z plane). Negative values are treated as M_PI - abs(angle)
cov	entries of the covariance matrix.

setLER() [1/2]

void setLER ( const ROOT::Math::PxPyPzEVector &  ler )

inline

Set the Low Energy Beam 4-momentum.

Definition at line 144 of file MCInitialParticles.h.

    {
      m_ler = ler;
      resetBoost();
    }

setLER() [2/2]

void setLER	(	double	energy,
		double	angleX,
		double	angleY,
		const std::vector< double > &	cov
	)

Set the LER FourVector and error matrix from beam energy, angle and covariance entries.

The vector for the covariance matrix can have either 0, 1, 3, 6 or 9 entries:

• 0 entries means no error.
• 1 entry will be treated as the variance of the beam energy.
• 3 entries will be treated as uncorrelated variances for all variables (diagonal of the matrix)
• 6 entries will be interpreted as the upper triangle of the covariance matrix with the element order being (0, 0), (0, 1), (0, 2), (1, 1), (1, 2), (2, 2)
• 9 entries for the full covariance matrix in row-major order. The symmetry of the matrix will not be checked but just the lower triangle will be used.

Parameters

energy	beam energy
angleX	angle between beam direction and z axis (in the x-z plane). Negative values are treated as M_PI - abs(angle)
angleY	angle between beam direction and z axis (in the y-z plane). Negative values are treated as M_PI - abs(angle)
cov	entries of the covariance matrix.

setTime()

void setTime ( double  time )

inlineinherited

Set collision time.

Definition at line 157 of file MCInitialParticles.h.

{m_time = time;}

setVertex() [1/2]

void setVertex ( const ROOT::Math::XYZVector &  vertex )

inline

Set the vertex position.

Definition at line 151 of file MCInitialParticles.h.

    {
      m_vertex = vertex;
    }

setVertex() [2/2]

void setVertex	(	const ROOT::Math::XYZVector &	vertex,
		const std::vector< double > &	cov
	)

Set the vertex position and error matrix.

The vector for the covariance matrix can have either 0, 1, 3, 6 or 9 entries:

• 0 entries means no error.
• 1 entry will be treated as the common variance for x, y and z
• 3 entries will be treated as uncorrelated variances for all variables (diagonal of the matrix)
• 6 entries will be interpreted as the upper triangle of the covariance matrix with the element order being (0, 0), (0, 1), (0, 2), (1, 1), (1, 2), (2, 2)
• 9 entries for the full covariance matrix in row-major order. The symmetry of the matrix will not be checked but just the upper triangle will be used.

Parameters

vertex	vertex position
cov	entries of the covariance matrix.

Member Data Documentation

m_boostedHER

ROOT::Math::PxPyPzEVector m_boostedHER

mutableprivateinherited

transient

HER 4-momentum in CM frame obtained by pure boost (calculated on first use, not saved to file)

Definition at line 242 of file MCInitialParticles.h.

m_CMSToLab

ROOT::Math::LorentzRotation* m_CMSToLab {nullptr}

mutableprivateinherited

transient

Boost from CMS into lab. (calculated on first use, not saved to file)

Definition at line 238 of file MCInitialParticles.h.

m_covHER

Double32_t m_covHER[6]

private

Covariance matrix of the high energy beam at the IP.

Definition at line 207 of file BeamParameters.h.

m_covLER

Double32_t m_covLER[6]

private

Covariance matrix of the low energy beam at the IP.

Definition at line 210 of file BeamParameters.h.

m_covVertex

Double32_t m_covVertex[6]

private

Covariance matrix of the vertex position.

Definition at line 213 of file BeamParameters.h.

m_generationFlags

int m_generationFlags {0}

protectedinherited

Flags to be used when generating events.

Definition at line 249 of file MCInitialParticles.h.

m_her

ROOT::Math::PxPyPzEVector m_her

privateinherited

HER 4vector.

Definition at line 228 of file MCInitialParticles.h.

m_invariantMass

double m_invariantMass {0.0}

mutableprivateinherited

transient

invariant mass of HER+LER (calculated on first use, not saved to file)

Definition at line 240 of file MCInitialParticles.h.

m_labToCMS

ROOT::Math::LorentzRotation* m_labToCMS {nullptr}

mutableprivateinherited

Boost from Lab into CMS.

(calculated on first use, not saved to file)

Definition at line 236 of file MCInitialParticles.h.

m_ler

ROOT::Math::PxPyPzEVector m_ler

privateinherited

LER 4vector.

Definition at line 230 of file MCInitialParticles.h.

m_time

double m_time = 0

privateinherited

collision time

Definition at line 234 of file MCInitialParticles.h.

m_validFlag

bool m_validFlag = false

privateinherited

transient

Flag to check if a valid MCInitialParticles object was already generated and filled in an event.

Definition at line 244 of file MCInitialParticles.h.

m_vertex

ROOT::Math::XYZVector m_vertex

privateinherited

collision position

Definition at line 232 of file MCInitialParticles.h.

---

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

• framework/dbobjects/include/BeamParameters.h