ActsFatras::Particle Class Reference

Particle identity information and kinematic state. More...

#include <ActsFatras/EventData/Particle.hpp>

Public Member Functions
	Particle ()=default
	Construct a default particle with invalid identity.
	Particle (Barcode particleId, Acts::PdgParticle pdg)
	Construct a particle at rest from a PDG particle number.
	Particle (Barcode particleId, Acts::PdgParticle pdg, double charge, double mass)
	Construct a particle at rest with explicit mass and charge.
	Particle (const Particle &)=default
	Copy constructor.
	Particle (Particle &&)=default
	Move constructor.
double	absoluteCharge () const
	Particle absolute charge.
double	absoluteMomentum () const
	Absolute momentum.
Acts::PdgParticle	absolutePdg () const
	Absolute PDG particle number that identifies the type.
Acts::Result< Acts::BoundTrackParameters >	boundParameters (const Acts::GeometryContext &gctx) const
	Bound track parameters.
double	charge () const
	Particle charge.
Acts::BoundTrackParameters	curvilinearParameters () const
const Acts::Vector3 &	direction () const
	Unit three-direction, i.e.
double	energy () const
	Total energy, i.e.
Acts::Vector4	fourMomentum () const
	Energy-momentum four-vector.
const Acts::Vector4 &	fourPosition () const
	Space-time position four-vector.
bool	hasReferenceSurface () const
	Check if the particle has a reference surface.
Acts::ParticleHypothesis	hypothesis () const
	Particle hypothesis.
bool	isAlive () const
	Check if the particle is alive, i.e.
bool	isSecondary () const
	Check if this is a secondary particle.
void	killParticle (SimulationOutcome outcome)
	Kill the particle by setting the outcome to a non-alive status.
Particle &	loseEnergy (double delta, SimulationOutcome stoppedOutcome=SimulationOutcome::Alive)
	Reduce the energy by the given amount.
double	mass () const
	Particle mass.
Acts::Vector3	momentum () const
	Absolute momentum.
std::uint32_t	numberOfHits () const
	Number of hits.
Particle &	operator= (const Particle &)=default
	Copy assignment operator.
Particle &	operator= (Particle &&)=default
	Move assignment operator.
SimulationOutcome	outcome () const
	Particle outcome.
Barcode	particleId () const
	Particle identifier within an event.
double	pathInL0 () const
	Accumulated path within material measured in interaction lengths.
double	pathInX0 () const
	Accumulated path within material measured in radiation lengths.
Acts::PdgParticle	pdg () const
	PDG particle number that identifies the type.
double	phi () const
	Azimuthal angle.
auto	position () const
	Three-position, i.e.
GenerationProcess	process () const
	Which type of process generated this particle.
double	properTime () const
	Proper time in the particle rest frame.
double	qOverP () const
	Particl qOverP.
const Acts::Surface *	referenceSurface () const
	Reference surface.
Particle &	setAbsoluteMomentum (double absMomentum)
	Set the absolute momentum.
Particle	setCharge (double charge)
	Set the charge.
Particle &	setDirection (const Acts::Vector3 &direction)
	Set the direction three-vector.
Particle &	setDirection (double dx, double dy, double dz)
	Set the direction three-vector from scalar components.
Particle	setMass (double mass)
	Set the mass.
Particle &	setMaterialPassed (double pathInX0, double pathInL0)
	Set the accumulated material measured in radiation/interaction lengths.
Particle &	setNumberOfHits (std::uint32_t nHits)
	Set the number of hits.
Particle &	setOutcome (SimulationOutcome outcome)
	Set the outcome of particle.
Particle &	setParticleId (Barcode barcode)
	Set the particle ID.
Particle	setPdg (Acts::PdgParticle pdg)
	Set the pdg.
Particle &	setPosition4 (const Acts::Vector3 &position, double time)
	Set the space-time position four-vector from three-position and time.
Particle &	setPosition4 (const Acts::Vector4 &pos4)
	Set the space-time position four-vector.
Particle &	setPosition4 (double x, double y, double z, double time)
	Set the space-time position four-vector from scalar components.
Particle &	setProcess (GenerationProcess proc)
	Set the process type that generated this particle.
Particle &	setProperTime (double properTime)
	Set the proper time in the particle rest frame.
Particle &	setReferenceSurface (const Acts::Surface *surface)
	Set the reference surface.
double	theta () const
	Polar angle.
double	time () const
	Time coordinate.
double	transverseMomentum () const
	Absolute momentum in the x-y plane.
Particle	withParticleId (Barcode particleId) const
	Construct a new particle with a new identifier but same kinematics.

Detailed Description

Particle identity information and kinematic state.

Also stores some simulation-specific properties.

Constructor & Destructor Documentation

Particle() [1/2]

ActsFatras::Particle::Particle	(	Barcode	particleId,
		Acts::PdgParticle	pdg,
		double	charge,
		double	mass )

Construct a particle at rest with explicit mass and charge.

Parameters

particleId	Particle identifier within an event
pdg	PDG id
charge	Particle charge in native units
mass	Particle mass in native units

Warning

It is the users responsibility that charge and mass match the PDG particle number.

Particle() [2/2]

ActsFatras::Particle::Particle	(	Barcode	particleId,
		Acts::PdgParticle	pdg )

Construct a particle at rest from a PDG particle number.

Parameters

particleId	Particle identifier within an event
pdg	PDG particle number

Charge and mass are retrieved from the particle data table.

Member Function Documentation

absoluteCharge()

double ActsFatras::Particle::absoluteCharge

(

)

const

Particle absolute charge.

Returns

The absolute particle charge (positive value)

absoluteMomentum()

double ActsFatras::Particle::absoluteMomentum

(

)

const

Absolute momentum.

Returns

The absolute momentum magnitude

absolutePdg()

Acts::PdgParticle ActsFatras::Particle::absolutePdg

(

)

const

Absolute PDG particle number that identifies the type.

Returns

The absolute PDG particle identifier (positive value)

boundParameters()

Acts::Result< Acts::BoundTrackParameters > ActsFatras::Particle::boundParameters

(

const Acts::GeometryContext &

gctx

)

const

Bound track parameters.

Parameters

gctx	Geometry context for coordinate transformations

Returns

Result containing bound track parameters or error if no reference surface

charge()

double ActsFatras::Particle::charge

(

)

const

Particle charge.

Returns

The particle charge in native units

curvilinearParameters()

Acts::BoundTrackParameters ActsFatras::Particle::curvilinearParameters

(

)

const

Returns

Curvilinear track parameters representation

direction()

const Acts::Vector3 & ActsFatras::Particle::direction

(

)

const

Unit three-direction, i.e.

the normalized momentum three-vector.

Returns

Reference to the normalized direction vector

energy()

double ActsFatras::Particle::energy

(

)

const

Total energy, i.e.

norm of the four-momentum.

Returns

The total energy calculated from mass and momentum

fourMomentum()

Acts::Vector4 ActsFatras::Particle::fourMomentum

(

)

const

Energy-momentum four-vector.

Returns

Four-dimensional momentum vector (px, py, pz, E)

fourPosition()

const Acts::Vector4 & ActsFatras::Particle::fourPosition

(

)

const

Space-time position four-vector.

Returns

Reference to the four-dimensional position vector (x, y, z, t)

hasReferenceSurface()

bool ActsFatras::Particle::hasReferenceSurface

(

)

const

Check if the particle has a reference surface.

Returns

True if reference surface is set, false otherwise

hypothesis()

Acts::ParticleHypothesis ActsFatras::Particle::hypothesis

(

)

const

Particle hypothesis.

Returns

Particle hypothesis containing PDG, mass, and charge information

isAlive()

bool ActsFatras::Particle::isAlive

(

)

const

Check if the particle is alive, i.e.

is not at rest.

Returns

True if particle has non-zero momentum, false otherwise

isSecondary()

bool ActsFatras::Particle::isSecondary

(

)

const

Check if this is a secondary particle.

Returns

True if particle is a secondary (has non-zero vertex secondary, generation, or sub-particle), false otherwise

killParticle()

void ActsFatras::Particle::killParticle

(

SimulationOutcome

outcome

)

Kill the particle by setting the outcome to a non-alive status.

Parameters

outcome

The outcome status to set for the killed particle (must not be Alive)

Exceptions

std::invalid_argument

if the provided outcome is Alive

loseEnergy()

Particle & ActsFatras::Particle::loseEnergy	(	double	delta,
		SimulationOutcome	stoppedOutcome = SimulationOutcome::Alive )

Reduce the energy by the given amount.

If the energy loss exceeds the current energy, the particle is killed with the specified outcome. If stopping the particle was not expected (stoppedOutcome is Alive), an exception is thrown.

Parameters

delta	The energy loss amount to subtract from the current energy
stoppedOutcome	The outcome to set if the energy loss exceeds the current energy

Returns

Reference to this particle for method chaining

Exceptions

std::invalid_argument

if the energy loss exceeds the current energy and stoppedOutcome is Alive

mass()

double ActsFatras::Particle::mass

(

)

const

Particle mass.

Returns

The particle mass in native units

momentum()

Acts::Vector3 ActsFatras::Particle::momentum

(

)

const

Absolute momentum.

Returns

Three-dimensional momentum vector

numberOfHits()

std::uint32_t ActsFatras::Particle::numberOfHits

(

)

const

Number of hits.

Returns

The number of hits associated with this particle

operator=() [1/2]

Particle & ActsFatras::Particle::operator= ( const Particle & )

default

Copy assignment operator.

Returns

Reference to this particle after copying

operator=() [2/2]

Particle & ActsFatras::Particle::operator= ( Particle && )

default

Move assignment operator.

Returns

Reference to this particle after moving

outcome()

SimulationOutcome ActsFatras::Particle::outcome

(

)

const

Particle outcome.

Returns

The outcome status of this particle

particleId()

Barcode ActsFatras::Particle::particleId

(

)

const

Particle identifier within an event.

Returns

The unique particle identifier barcode

pathInL0()

double ActsFatras::Particle::pathInL0

(

)

const

Accumulated path within material measured in interaction lengths.

Returns

The accumulated path in interaction lengths

pathInX0()

double ActsFatras::Particle::pathInX0

(

)

const

Accumulated path within material measured in radiation lengths.

Returns

The accumulated path in radiation lengths

pdg()

Acts::PdgParticle ActsFatras::Particle::pdg

(

)

const

PDG particle number that identifies the type.

Returns

The PDG particle identifier

phi()

double ActsFatras::Particle::phi

(

)

const

Azimuthal angle.

Returns

The azimuthal angle (phi) in radians

position()

auto ActsFatras::Particle::position

(

)

const

Three-position, i.e.

spatial coordinates without the time.

Returns

Three-dimensional position vector (x, y, z)

process()

GenerationProcess ActsFatras::Particle::process

(

)

const

Which type of process generated this particle.

Returns

The process type that generated this particle

properTime()

double ActsFatras::Particle::properTime

(

)

const

Proper time in the particle rest frame.

Returns

The proper time in the rest frame

qOverP()

double ActsFatras::Particle::qOverP

(

)

const

Particl qOverP.

Returns

The charge over momentum ratio

referenceSurface()

const Acts::Surface * ActsFatras::Particle::referenceSurface

(

)

const

Reference surface.

Returns

Pointer to the reference surface, or nullptr if not set

setAbsoluteMomentum()

Particle & ActsFatras::Particle::setAbsoluteMomentum

(

double

absMomentum

)

Set the absolute momentum.

Parameters

absMomentum

Absolute momentum magnitude

Returns

Reference to this particle for method chaining

Exceptions

std::invalid_argument

if absMomentum is negative

setCharge()

Particle ActsFatras::Particle::setCharge

(

double

charge

)

Set the charge.

Parameters

charge

Particle charge in native units

Returns

Particle instance with updated charge

setDirection() [1/2]

Particle & ActsFatras::Particle::setDirection

(

const Acts::Vector3 &

direction

)

Set the direction three-vector.

Parameters

direction

Three-dimensional direction vector (will be normalized)

Returns

Reference to this particle for method chaining

setDirection() [2/2]

Particle & ActsFatras::Particle::setDirection	(	double	dx,
		double	dy,
		double	dz )

Set the direction three-vector from scalar components.

Parameters

dx	X component of direction
dy	Y component of direction
dz	Z component of direction

Returns

Reference to this particle for method chaining

setMass()

Particle ActsFatras::Particle::setMass

(

double

mass

)

Set the mass.

Parameters

mass	Particle mass in native units

Returns

Particle instance with updated mass

setMaterialPassed()

Particle & ActsFatras::Particle::setMaterialPassed	(	double	pathInX0,
		double	pathInL0 )

Set the accumulated material measured in radiation/interaction lengths.

Parameters

pathInX0	accumulated material measured in radiation lengths
pathInL0	accumulated material measured in interaction lengths

Returns

Reference to this particle for method chaining

setNumberOfHits()

Particle & ActsFatras::Particle::setNumberOfHits

(

std::uint32_t

nHits

)

Set the number of hits.

Parameters

nHits

number of hits

Returns

Reference to this particle for method chaining

setOutcome()

Particle & ActsFatras::Particle::setOutcome

(

SimulationOutcome

outcome

)

Set the outcome of particle.

Parameters

outcome

outcome code

Returns

Reference to this particle for method chaining

setParticleId()

Particle & ActsFatras::Particle::setParticleId

(

Barcode

barcode

)

Set the particle ID.

Parameters

barcode

New particle identifier barcode

Returns

Reference to this particle for method chaining

setPdg()

Particle ActsFatras::Particle::setPdg

(

Acts::PdgParticle

pdg

)

Set the pdg.

Parameters

pdg	PDG particle identifier

Returns

Particle instance with updated PDG identifier

setPosition4() [1/3]

Particle & ActsFatras::Particle::setPosition4	(	const Acts::Vector3 &	position,
		double	time )

Set the space-time position four-vector from three-position and time.

Parameters

position	Three-dimensional spatial position vector
time	Time coordinate

Returns

Reference to this particle for method chaining

setPosition4() [2/3]

Particle & ActsFatras::Particle::setPosition4

(

const Acts::Vector4 &

pos4

)

Set the space-time position four-vector.

Parameters

pos4	Four-vector containing spatial position and time

Returns

Reference to this particle for method chaining

setPosition4() [3/3]

Particle & ActsFatras::Particle::setPosition4	(	double	x,
		double	y,
		double	z,
		double	time )

Set the space-time position four-vector from scalar components.

Parameters

x	X coordinate
y	Y coordinate
z	Z coordinate
time	Time coordinate

Returns

Reference to this particle for method chaining

setProcess()

Particle & ActsFatras::Particle::setProcess

(

GenerationProcess

proc

)

Set the process type that generated this particle.

Parameters

proc	Process type that generated this particle

Returns

Reference to this particle for method chaining

setProperTime()

Particle & ActsFatras::Particle::setProperTime

(

double

properTime

)

Set the proper time in the particle rest frame.

Parameters

properTime

passed proper time in the rest frame

Returns

Reference to this particle for method chaining

setReferenceSurface()

Particle & ActsFatras::Particle::setReferenceSurface

(

const Acts::Surface *

surface

)

Set the reference surface.

Parameters

surface

Reference surface for bound track parameters

Returns

Reference to this particle for method chaining

theta()

double ActsFatras::Particle::theta

(

)

const

Polar angle.

Returns

The polar angle (theta) in radians

time()

double ActsFatras::Particle::time

(

)

const

Time coordinate.

Returns

The time coordinate value

transverseMomentum()

double ActsFatras::Particle::transverseMomentum

(

)

const

Absolute momentum in the x-y plane.

Returns

The transverse momentum magnitude

withParticleId()

Particle ActsFatras::Particle::withParticleId

(

Barcode

particleId

)

const

Construct a new particle with a new identifier but same kinematics.

Parameters

particleId

New particle identifier to assign

Returns

New particle instance with updated identifier but same kinematics

Note

This is intentionally not a regular setter. The particle id is used to identify the whole particle. Setting it on an existing particle is usually a mistake.