Acts::AnyCharge Class Reference

Charge and momentum interpretation for arbitrarily charged particles. More...

#include <Acts/EventData/Charge.hpp>

Public Member Functions
constexpr	AnyCharge (float absQ) noexcept
	Construct with the magnitude of the input charge.
constexpr	AnyCharge (Neutral) noexcept
	Construct from a Neutral particle.
constexpr	AnyCharge (SinglyCharged) noexcept
	Construct from a SinglyCharged particle.
constexpr float	absQ () const noexcept
	Get the absolute charge magnitude.
constexpr float	extractCharge (double qOverP) const noexcept
	Extract the signed charge from q/p.
constexpr double	extractMomentum (double qOverP) const noexcept
	Extract momentum magnitude from q/p.
constexpr double	qOverP (double momentum, float signedQ) const noexcept
	Compute q/p from momentum and signed charge.

Detailed Description

Charge and momentum interpretation for arbitrarily charged particles.

Only a charge magnitude identical to zero is interpreted as representing a neutral particle. This avoids ambiguities that might arise from using an approximate comparison with an arbitrary epsilon.

Constructor & Destructor Documentation

AnyCharge() [1/3]

Acts::AnyCharge::AnyCharge ( float absQ )

explicitconstexprnoexcept

Construct with the magnitude of the input charge.

Parameters

absQ	The absolute value of the charge magnitude

AnyCharge() [2/3]

Acts::AnyCharge::AnyCharge ( SinglyCharged )

explicitconstexprnoexcept

Construct from a SinglyCharged particle.

AnyCharge() [3/3]

Acts::AnyCharge::AnyCharge ( Neutral )

explicitconstexprnoexcept

Construct from a Neutral particle.

Member Function Documentation

absQ()

float Acts::AnyCharge::absQ ( ) const

constexprnoexcept

Get the absolute charge magnitude.

Returns

Absolute charge magnitude (0 for neutral particles)

extractCharge()

float Acts::AnyCharge::extractCharge ( double qOverP ) const

constexprnoexcept

Extract the signed charge from q/p.

Parameters

qOverP

Charge over momentum

Returns

Signed charge with correct magnitude (0 for neutral)

extractMomentum()

double Acts::AnyCharge::extractMomentum ( double qOverP ) const

constexprnoexcept

Extract momentum magnitude from q/p.

Parameters

qOverP

Charge over momentum

Returns

Momentum magnitude (handles both charged and neutral particles)

qOverP()

double Acts::AnyCharge::qOverP ( double momentum, float signedQ ) const

constexprnoexcept

Compute q/p from momentum and signed charge.

Parameters

momentum	Particle momentum magnitude
signedQ	Signed charge (must match stored charge magnitude)

Returns

Charge over momentum (handles both charged and neutral particles)