UtilityBase is a base class implementing a number of static utility functions. More...

#include <UtilityBase.h>

Inheritance diagram for ThePEG::UtilityBase:

Static Public Member Functions
template<typename Cont >
static LorentzMomentum	sumMomentum (const Cont &c)
	Sums the four-momentum of given container.

template<typename Iterator >
static LorentzMomentum	sumMomentum (Iterator first, Iterator last)
	Sums the four-momentum of the entries between first and last.

template<typename Iterator >
static void	transform (Iterator first, Iterator last, const LorentzRotation &boost)
	Transform the entries between first and last.

template<typename Cont >
static void	transform (Cont &cont, const LorentzRotation &boost)
	Transform the entries in a container cont.

template<typename PType >
static LorentzRotation	boostToCM (const pair< PType, PType > &pp)
	Boost the two objects in the pair to their CM system.

template<typename PType >
static LorentzRotation	boostToCM (const Triplet< PType, PType, PType > &pt)
	Boost the three objects in the Triplet to their CM system.

template<typename PType >
static LorentzRotation	getBoostToCM (const pair< PType, PType > &pp)
	Obtain the LorentzRotation needed to boost the two objects in the pair to their CM system.

template<typename PType >
static LorentzRotation	getBoostToCM (const Triplet< PType, PType, PType > &pt)
	Obtain the LorentzRotation needed to boost the three objects in the Triplet to their CM system.

template<typename PType >
static LorentzRotation	getBoostFromCM (const pair< PType, PType > &pp)
	Get the inverse boost as compared to getBoostToCM.

template<typename PType >
static LorentzRotation	getBoostFromCM (const Triplet< PType, PType, PType > &pt)
	Get the inverse boost as compared to getBoostToCM.

template<typename Iterator >
static LorentzRotation	boostToCM (Iterator first, Iterator last)
	Boost the entries between fisrt and last into their CM system.

template<typename Iterator >
static LorentzRotation	boostToCM (Iterator first, Iterator last, Iterator zAxis)
	Boost the entries between fisrt and last into their CM system.

template<typename Iterator >
static LorentzRotation	boostToCM (Iterator first, Iterator last, Iterator zAxis, Iterator xzPlane)
	Boost the entries between fisrt and last into their CM system.

template<typename PType >
static void	setMomentum (PType &p, const Momentum3 &q)
	Rotate p to the z-axis and boost it to its CMS, then boost it along the z-axis and rotate it so that it ends up with momentum q.

template<typename PType >
static void	setMomentumFromCMS (PType &p, const Momentum3 &q)
	Boost p along the z-axis and rotate it so that, if it was previously at rest, it ends up with momentum q.

template<typename Iter >
static void	setMomentum (Iter first, Iter last, const Momentum3 &q)
	Rotate the range of particles so their sum is along z-axis and boost them to their CMS, then boost them along the z-axis and rotate them so that they end up with total momentum q.

template<typename Iter >
static void	setMomentum (Iter first, Iter last, const Momentum3 &q, double eps)
	Rotate the range of particles so their sum is along z-axis then boost them along the z-axis and rotate them so that they end up with total momentum q.

template<typename Iter >
static void	setMomentumFromCMS (Iter first, Iter last, Energy2 m2, const Momentum3 &q)
	Boost the range of particles along the z-axis and rotate them so that, if they were previously in their rest frame, they end up with total momentum q.

template<typename PType >
static LorentzRotation	transformToMomentum (const PType &p, const Momentum3 &q)
	Return the transformation needed to rotate p to the z-axis and boost it to its CMS, then boost it along the z-axis and rotate it so that it ends up with momentum q.

template<typename PType >
static LorentzRotation	transformToMomentum (const PType &p, const LorentzMomentum &q)
	Return the transformation needed to rotate p to the z-axis and boost it to its CMS, then boost it along the z-axis and rotate it so that it ends up with momentum q.

template<typename PType >
static LorentzRotation	getTransformToMomentum (const PType &p, const LorentzMomentum &q, const LorentzMomentum &k)
	Return a transformation appropriate for transforming p to have the momentum q.

template<typename PType >
static LorentzRotation	getTransformToMomentum (const PType &p, const Momentum3 &q, const LorentzMomentum &k)
	Return a transformation appropriate for transforming p to have the momentum q.

template<typename LV >
static LorentzRotation	transformFromCMS (const LV &p)
	Create a rotation corresponding to transforming p to its current value from its CMS by first boosting along the z-axis and then rotating.

template<typename LV >
static LorentzRotation	transformFromCMS (const LV &sum, LV zAxis)
	Create a rotation corresponding to transforming sum to its current value from its CMS, with zAxis along the z-axis in that CMS frame.

template<typename LV >
static LorentzRotation	transformFromCMS (const LV &sum, const LV &zAxis, LV xyPlane)
	Create a rotation corresponding to transforming sum to its current value from its CMS, with zAxis along the z-axis and xyPlane in the x-y plane in that CMS frame.

template<typename LV >
static LorentzRotation	transformToCMS (const LV &sum, LV zAxis)
	Create a rotation which would transform sum to its CMS frame with zAxis along the z-axis in that frame.

template<typename LV >
static LorentzRotation	transformToCMS (const LV &p)
	Create a rotation which would transform sum to its CMS frame first rotating it to the z-axis and then boost it along the z-axis.

template<typename LV >
static LorentzRotation	transformToCMS (const LV &sum, const LV &zAxis, LV xyPlane)
	Create a rotation which would transform sum to its CMS frame with zAxis along the z-axis and xyPlane in the x-y plane in that frame.

template<typename Cont1 , typename Cont2 >
static void	add (Cont1 &c1, const Cont2 &c2)
	Add the elements in Cont2 to Cont1, appending them to the end if possible.

Detailed Description

UtilityBase is a base class implementing a number of static utility functions.

It should be used as a base class to give acces to these functions to a class. A class can safely multiply inherit from this class as it only contains static functions.

Definition at line 24 of file UtilityBase.h.

Member Function Documentation

◆ boostToCM() [1/5]

template<typename PType >

static LorentzRotation ThePEG::UtilityBase::boostToCM ( const pair< PType, PType > & pp )

static

Boost the two objects in the pair to their CM system.

Also rotate so that the first is along the z-axis. The class PType must have ParticleTraits<PType>::momentum(const PType&) and ParticleTraits<PType>::transform(PType&, const LorentzRotation&) implemented correctly.

Referenced by boostToCM().

◆ boostToCM() [2/5]

template<typename PType >

static LorentzRotation ThePEG::UtilityBase::boostToCM ( const Triplet< PType, PType, PType > & pt )

static

Boost the three objects in the Triplet to their CM system.

Also rotate so that the first is along the z-axis and the second is in the x-z plane with positive x. The class PType must have ParticleTraits<PType>::momentum(const PType&) and ParticleTraits<PType>::transform(PType&, const LorentzRotation&) implemented correctly.

◆ boostToCM() [3/5]

template<typename Iterator >

static LorentzRotation ThePEG::UtilityBase::boostToCM	(	Iterator	first,
		Iterator	last
	)

inlinestatic

Boost the entries between fisrt and last into their CM system.

The class Iterator::value_type must be of a type T for which ParticleTraits<T>::momentum(const T&) and ParticleTraits<T>::transform(T&, const LorentzRotation&) are implemented correctly.

Definition at line 142 of file UtilityBase.h.

References boostToCM().

◆ boostToCM() [4/5]

template<typename Iterator >

static LorentzRotation ThePEG::UtilityBase::boostToCM	(	Iterator	first,
		Iterator	last,
		Iterator	zAxis
	)

inlinestatic

Boost the entries between fisrt and last into their CM system.

If zAxis != last, also rotate the entries so that zAxis becomes paralell to the z-axis. The class Iterator::value_type must be of a type T for which ParticleTraits<T>::momentum(const T&) and ParticleTraits<T>::transform(T&, const LorentzRotation&) are implemented correctly.

Definition at line 156 of file UtilityBase.h.

References boostToCM().

◆ boostToCM() [5/5]

template<typename Iterator >

static LorentzRotation ThePEG::UtilityBase::boostToCM	(	Iterator	first,
		Iterator	last,
		Iterator	zAxis,
		Iterator	xzPlane
	)

static

Boost the entries between fisrt and last into their CM system.

If zAxis != last, also rotate the entries so that zAxis becomes paralell to the z-axis. Also, if xzPlane != last, rotate the entries so that xzPlane is placed in the xz-plane. The class Iterator::value_type must be of a type T for which ParticleTraits<T>::momentum(const T&) and ParticleTraits<T>::transform(T&, const LorentzRotation&) are implemented correctly.

◆ getBoostToCM() [1/2]

template<typename PType >

static LorentzRotation ThePEG::UtilityBase::getBoostToCM ( const pair< PType, PType > & pp )

static

Obtain the LorentzRotation needed to boost the two objects in the pair to their CM system.

Also rotate the LorentzRotation so that the first is along the z-axis. The class PType must have ParticleTraits<PType>::momentum(const PType&) implemented correctly.

Referenced by getTransformToMomentum().

◆ getBoostToCM() [2/2]

template<typename PType >

static LorentzRotation ThePEG::UtilityBase::getBoostToCM ( const Triplet< PType, PType, PType > & pt )

static

Obtain the LorentzRotation needed to boost the three objects in the Triplet to their CM system.

Also rotate the LorentzRotation so that the first is along the z-axis and the secons i in the x-z plane with positive x. The class PType must have ParticleTraits<PType>::momentum(const PType&) implemented correctly.

◆ getTransformToMomentum() [1/2]

template<typename PType >

static LorentzRotation ThePEG::UtilityBase::getTransformToMomentum	(	const PType &	p,
		const LorentzMomentum &	q,
		const LorentzMomentum &	k
	)

inlinestatic

Return a transformation appropriate for transforming p to have the momentum q.

The transformation is done so that the auxiliary vector k is left unchanged.

Definition at line 281 of file UtilityBase.h.

References getBoostFromCM(), and getBoostToCM().

Referenced by getTransformToMomentum().

◆ getTransformToMomentum() [2/2]

template<typename PType >

static LorentzRotation ThePEG::UtilityBase::getTransformToMomentum	(	const PType &	p,
		const Momentum3 &	q,
		const LorentzMomentum &	k
	)

inlinestatic

Return a transformation appropriate for transforming p to have the momentum q.

The transformation is done so that the auxiliary vector k is left unchanged.

Definition at line 296 of file UtilityBase.h.

References getTransformToMomentum(), and ThePEG::ThreeVector< Value >::mag2().

◆ setMomentum() [1/3]

template<typename Iter >

static void ThePEG::UtilityBase::setMomentum	(	Iter	first,
		Iter	last,
		const Momentum3 &	q
	)

static

Rotate the range of particles so their sum is along z-axis and boost them to their CMS, then boost them along the z-axis and rotate them so that they end up with total momentum q.

The class Iter::value_type must be of a type T for which ParticleTraits<T>::momentum(const T&) and ParticleTraits<T>::transform(T&, const LorentzRotation&) are implemented correctly.

◆ setMomentum() [2/3]

template<typename Iter >

static void ThePEG::UtilityBase::setMomentum	(	Iter	first,
		Iter	last,
		const Momentum3 &	q,
		double	eps
	)

static

Rotate the range of particles so their sum is along z-axis then boost them along the z-axis and rotate them so that they end up with total momentum q.

If a single boost does not succeed to obtain the required precision within eps times the total energy, the boost is redone. The class Iter::value_type must be of a type T for which ParticleTraits<T>::momentum(const T&) and ParticleTraits<T>::transform(T&, const LorentzRotation&) are implemented correctly.

◆ setMomentum() [3/3]

template<typename PType >

static void ThePEG::UtilityBase::setMomentum	(	PType &	p,
		const Momentum3 &	q
	)

static

Rotate p to the z-axis and boost it to its CMS, then boost it along the z-axis and rotate it so that it ends up with momentum q.

If p is massless - simply set its momentum. The class PType must have ParticleTraits<PType>::momentum(const PType&) implemented correctly.

◆ setMomentumFromCMS() [1/2]

template<typename Iter >

static void ThePEG::UtilityBase::setMomentumFromCMS	(	Iter	first,
		Iter	last,
		Energy2	m2,
		const Momentum3 &	q
	)

static

Boost the range of particles along the z-axis and rotate them so that, if they were previously in their rest frame, they end up with total momentum q.

The class Iter::value_type must be of a type T for which ParticleTraits<T>::momentum(const T&) and ParticleTraits<T>::transform(T&, const LorentzRotation&) are implemented correctly.

Parameters

first	iterator pointing to the first particle in the range.
last	iterator indicating the end of the range.
m2	the invariant mass squared of the particles.
q	final summed momentum of the particles.

◆ setMomentumFromCMS() [2/2]

template<typename PType >

static void ThePEG::UtilityBase::setMomentumFromCMS	(	PType &	p,
		const Momentum3 &	q
	)

static

Boost p along the z-axis and rotate it so that, if it was previously at rest, it ends up with momentum q.

If p is massless

simply set its momentum to q. The class PType must have ParticleTraits<PType>::momentum(const PType&) implemented correctly.

◆ sumMomentum() [1/2]

template<typename Cont >

static LorentzMomentum ThePEG::UtilityBase::sumMomentum ( const Cont & c )

inlinestatic

Sums the four-momentum of given container.

The class Cont::value_type must be of a type T for which ParticleTraits<T>::momentum(const T&) is implemented correctly.

Definition at line 33 of file UtilityBase.h.

References sumMomentum().

Referenced by sumMomentum().

◆ sumMomentum() [2/2]

template<typename Iterator >

static LorentzMomentum ThePEG::UtilityBase::sumMomentum	(	Iterator	first,
		Iterator	last
	)

inlinestatic

Sums the four-momentum of the entries between first and last.

The class Iterator::value_type must be of a type T for which ParticleTraits<T>::momentum(const T&) is implemented correctly.

Definition at line 44 of file UtilityBase.h.

◆ transform() [1/2]

template<typename Cont >

static void ThePEG::UtilityBase::transform	(	Cont &	cont,
		const LorentzRotation &	boost
	)

inlinestatic

Transform the entries in a container cont.

The class Cont::value_type must be of a type T for which ParticleTraits<T>::momentum(const T&) is implemented correctly.

Definition at line 75 of file UtilityBase.h.

References transform().

◆ transform() [2/2]

template<typename Iterator >

static void ThePEG::UtilityBase::transform	(	Iterator	first,
		Iterator	last,
		const LorentzRotation &	boost
	)

inlinestatic

Transform the entries between first and last.

The class Iterator::value_type must be of a type T for which ParticleTraits<T>::momentum(const T&) is implemented correctly.

Definition at line 60 of file UtilityBase.h.

Referenced by transform().

◆ transformFromCMS() [1/3]

template<typename LV >

static LorentzRotation ThePEG::UtilityBase::transformFromCMS ( const LV & p )

static

Create a rotation corresponding to transforming p to its current value from its CMS by first boosting along the z-axis and then rotating.

The class LV must have methods rho() and e().

Referenced by transformToMomentum().

◆ transformFromCMS() [2/3]

template<typename LV >

static LorentzRotation ThePEG::UtilityBase::transformFromCMS	(	const LV &	sum,
		const LV &	zAxis,
		LV	xyPlane
	)

static

Create a rotation corresponding to transforming sum to its current value from its CMS, with zAxis along the z-axis and xyPlane in the x-y plane in that CMS frame.