Momentum Class Reference

Container for a particle's 4-momentum, along with useful methods to ease the development of any matrix element level generator. More...

#include <CepGen/Physics/Momentum.h>

Inheritance diagram for Momentum:

Collaboration diagram for Momentum:

Public Member Functions
	Momentum (double x=0., double y=0., double z=0., double t=-1.)
	Build a 4-momentum using its 3-momentum coordinates and its energy.
	Momentum (double *p)
	Build a 4-momentum using its 3-momentum coordinates and its energy.
	Momentum (const Vector &)
	Build a 4-momentum using its 3-momentum coordinates and its energy.
bool	operator== (const Momentum &) const
	Equality operator.
bool	operator!= (const Momentum &oth) const
	Inequality operator.
double	threeProduct (const Momentum &) const
	Scalar product of the 3-momentum with another 3-momentum.
double	fourProduct (const Momentum &) const
	Scalar product of the 4-momentum with another 4-momentum.
double	crossProduct (const Momentum &) const
	Vector product of the 3-momentum with another 3-momentum.
Momentum	operator+ (const Momentum &) const
	Compute the 4-vector sum of two 4-momenta.
Momentum &	operator+= (const Momentum &)
	Add a 4-momentum through a 4-vector sum.
Momentum	operator- () const
	Unary inverse operator.
Momentum	operator- (const Momentum &) const
	Compute the inverse per-coordinate 4-vector.
Momentum &	operator-= (const Momentum &)
	Subtract a 4-momentum through a 4-vector sum.
double	operator* (const Momentum &) const
	Scalar product of two 3-momenta.
Momentum	operator% (const Momentum &) const
	Vector product of two 3-momenta.
double	operator*= (const Momentum &)
	Scalar product of the 3-momentum with another 3-momentum.
Momentum	operator* (double c) const
	Multiply all components of a 4-momentum by a scalar.
Momentum &	operator*= (double c)
	Multiply all 4-momentum coordinates by a scalar.
	operator Vector () const
	Cast the 4-momentum object into a 4-dimensional vector.
Momentum &	betaGammaBoost (double gamma, double betagamma)
	Forward \(\beta-\gamma\) boost.
Momentum &	lorentzBoost (const Momentum &p)
	Forward Lorentz boost.
Momentum &	setP (double px, double py, double pz, double e)
	Set all the components of the 4-momentum (in GeV)
Momentum &	setP (double px, double py, double pz)
	Set all the components of the 3-momentum (in GeV)
Momentum &	setPx (double px)
	Set the momentum along the \(x\)-axis (in GeV)
double	px () const
	Momentum along the \(x\)-axis (in GeV)
Momentum &	setPy (double py)
	Set the momentum along the \(y\)-axis (in GeV)
double	py () const
	Momentum along the \(y\)-axis (in GeV)
Momentum &	setPz (double pz)
	Set the longitudinal momentum (in GeV)
double	pz () const
	Longitudinal momentum (in GeV)
double	pt () const
	Transverse momentum (in GeV)
double	pt2 () const
	Squared transverse momentum (in GeV \(^2\))
Momentum	transverse () const
	Transverse coordinates of a momentum.
std::array< double, 5 >	pVector () const
	5-vector of double precision floats (in GeV)
double	p () const
	3-momentum norm (in GeV)
double	p2 () const
	Squared 3-momentum norm (in GeV \(^2\))
Momentum &	setEnergy (double)
	Set the energy (in GeV)
double	energy () const
	Energy (in GeV)
double	energy2 () const
	Squared energy (in GeV \(^2\))
double	energyT () const
	Tranverse energy component (in GeV)
double	energyT2 () const
	Squared tranverse energy component (in GeV \(^2\))
Momentum &	setMass2 (double)
	Compute the energy from the mass.
double	mass2 () const
	Squared mass (in GeV \(^2\)) as computed from its energy and momentum.
Momentum &	setMass (double)
	Compute the energy from the mass.
double	mass () const
	Mass (in GeV) as computed from its energy and momentum.
double	massT2 () const
	Squared transverse mass (in GeV \(^2\))
double	massT () const
	Transverse mass (in GeV)
double	theta () const
	Polar angle (angle with respect to the longitudinal direction)
double	phi () const
	Azimuthal angle (angle in the transverse plane)
double	eta () const
	Pseudo-rapidity.
double	rapidity () const
	Rapidity.
double	deltaEta (const Momentum &) const
	Pseudorapidity distance between two momenta.
double	deltaPhi (const Momentum &) const
	Azimutal angle opening between two momenta.
double	deltaPt (const Momentum &) const
	Transverse momentum distance between two momenta.
double	deltaR (const Momentum &) const
	Angular distance between two momenta.
double	beta () const
	Beta scalar value.
double	gamma2 () const
	Squared gamma scalar value.
double	gamma () const
	Gamma scalar value.
Momentum &	computeEnergyFromMass (double on_shell_mass)
	Compute the mass from 4-momentum.
Momentum &	computePzFromMass (double on_shell_mass)
	Compute the longitudinal coordinate from energy-mass-transverse momentum constraints.
Momentum &	truncate (double tolerance=1.e-10)
	Apply a threshold to all values with a given tolerance.
Momentum &	rotatePhi (double phi, double sign)
	Rotate the transverse components by an angle phi (and reflect the y coordinate)
Momentum &	rotateThetaPhi (double theta_, double phi_)
	Rotate the particle's momentum by a polar/azimuthal angle.
Momentum &	mirrorX ()
	Apply a \( x\rightarrow -x\) transformation.
Momentum &	mirrorY ()
	Apply a \( y\rightarrow -y\) transformation.
Momentum &	mirrorZ ()
	Apply a \( z\rightarrow -z\) transformation.

Static Public Member Functions
static Momentum	fromPtEtaPhiE (double pt, double eta, double phi, double e=-1.)
	Build a 3-momentum from its three pseudo-cylindrical coordinates.
static Momentum	fromPtEtaPhiM (double pt, double eta, double phi, double m)
	Build a 3-momentum from its three pseudo-cylindrical coordinates.
static Momentum	fromPThetaPhiE (double p, double theta, double phi, double e=-1.)
	Build a 4-momentum from its scalar momentum, and its polar and azimuthal angles.
static Momentum	fromPxPyPzE (double px, double py, double pz, double e)
	Build a 4-momentum from its four momentum and energy coordinates.
static Momentum	fromPxPyPzM (double px, double py, double pz, double m)
	Build a 4-momentum from its three momentum coordinates and mass.
static Momentum	fromPxPyYM (double px, double py, double rap, double m)
	Build a 4-momentum from its transverse momentum, rapidity and mass.
static Momentum	fromPtYPhiM (double pt, double rap, double phi, double m)
	Build a 4-momentum from its transverse momentum, azimuthal angle, rapidity and mass.

Friends
Momentum	operator* (double, const Momentum &)
	Left-multiply all 4-momentum coordinates by a scalar.
std::ostream &	operator<< (std::ostream &, const Momentum &)
	Human-readable format for a particle's momentum.

Detailed Description

4-momentum for a particle

Date

Dec 2015

Author

Laurent Forthomme laure.nosp@m.nt.f.nosp@m.ortho.nosp@m.mme@.nosp@m.cern..nosp@m.ch

Definition at line 33 of file Momentum.h.

Constructor & Destructor Documentation

Momentum() [1/3]

Momentum ( double  x = 0., double  y = 0., double  z = 0., double  t = -1.  )

explicit

Definition at line 45 of file Momentum.cpp.

Momentum() [2/3]

Momentum ( double *  p )

explicit

Definition at line 49 of file Momentum.cpp.

Momentum() [3/3]

Momentum ( const Vector &  vec )

explicit

Definition at line 54 of file Momentum.cpp.

Member Function Documentation

beta()

double beta

(

)

const

Definition at line 265 of file Momentum.cpp.

betaGammaBoost()

Momentum & betaGammaBoost	(	double	gamma,
		double	betagamma
	)

Definition at line 297 of file Momentum.cpp.

computeEnergyFromMass()

Momentum & computeEnergyFromMass

(

double

on_shell_mass

)

Parameters

[in]

on_shell_mass

Specify on-shell mass to constrain energy

Definition at line 187 of file Momentum.cpp.

computePzFromMass()

Momentum & computePzFromMass

(

double

on_shell_mass

)

Parameters

[in]

on_shell_mass

Specify on-shell mass to constrain longitudinal momentum

Definition at line 189 of file Momentum.cpp.

crossProduct()

double crossProduct

(

const Momentum &

mom

)

const

Definition at line 153 of file Momentum.cpp.

deltaEta()

double deltaEta

(

const Momentum &

oth

)

const

Definition at line 251 of file Momentum.cpp.

deltaPhi()

double deltaPhi

(

const Momentum &

oth

)

const

Definition at line 253 of file Momentum.cpp.

deltaPt()

double deltaPt

(

const Momentum &

oth

)

const

Definition at line 257 of file Momentum.cpp.

deltaR()

double deltaR

(

const Momentum &

oth

)

const

Definition at line 259 of file Momentum.cpp.

energy()

double energy

(

)

const

Definition at line 136 of file Momentum.h.

energy2()

double energy2

(

)

const

Definition at line 138 of file Momentum.h.

energyT()

double energyT

(

)

const

Definition at line 220 of file Momentum.cpp.

energyT2()

double energyT2

(

)

const

Definition at line 215 of file Momentum.cpp.

eta()

double eta

(

)

const

Definition at line 240 of file Momentum.cpp.

fourProduct()

double fourProduct

(

const Momentum &

mom

)

const

Definition at line 145 of file Momentum.cpp.

fromPtEtaPhiE()

Momentum fromPtEtaPhiE ( double  pt, double  eta, double  phi, double  e = -1.  )

static

Definition at line 69 of file Momentum.cpp.

fromPtEtaPhiM()

Momentum fromPtEtaPhiM ( double  pt, double  eta, double  phi, double  m  )

static

Definition at line 73 of file Momentum.cpp.

fromPThetaPhiE()

Momentum fromPThetaPhiE ( double  p, double  theta, double  phi, double  e = -1.  )

static

Definition at line 77 of file Momentum.cpp.

fromPtYPhiM()

Momentum fromPtYPhiM ( double  pt, double  rap, double  phi, double  m  )

static

Definition at line 93 of file Momentum.cpp.

fromPxPyPzE()

Momentum fromPxPyPzE ( double  px, double  py, double  pz, double  e  )

static

Definition at line 82 of file Momentum.cpp.

fromPxPyPzM()

Momentum fromPxPyPzM ( double  px, double  py, double  pz, double  m  )

static

Definition at line 84 of file Momentum.cpp.

fromPxPyYM()

Momentum fromPxPyYM ( double  px, double  py, double  rap, double  m  )

static

Definition at line 88 of file Momentum.cpp.

gamma()

double gamma

(

)

const

Definition at line 295 of file Momentum.cpp.

gamma2()

double gamma2

(

)

const

Definition at line 280 of file Momentum.cpp.

lorentzBoost()

Momentum & lorentzBoost

(

const Momentum &

p

)

Definition at line 306 of file Momentum.cpp.

mass()

double mass

(

)

const

Note

Returns \(-\sqrt{|E^2-\mathbf{p}^2|}<0\) if \(\mathbf{p}^2>E^2\)

Definition at line 224 of file Momentum.cpp.

mass2()

double mass2

(

)

const

Definition at line 222 of file Momentum.cpp.

massT()

double massT

(

)

const

Definition at line 228 of file Momentum.cpp.

massT2()

double massT2

(

)

const

Definition at line 226 of file Momentum.cpp.

mirrorX()

Momentum & mirrorX

(

)

Definition at line 196 of file Momentum.h.

mirrorY()

Momentum & mirrorY

(

)

Definition at line 201 of file Momentum.h.

mirrorZ()

Momentum & mirrorZ

(

)

Definition at line 206 of file Momentum.h.

operator Vector()

operator Vector

(

)

const

Definition at line 213 of file Momentum.cpp.

operator!=()

bool operator!=

(

const Momentum &

oth

)

const

Definition at line 43 of file Momentum.h.

operator%()

Momentum operator%

(

const Momentum &

mom

)

const

Definition at line 122 of file Momentum.cpp.

operator*() [1/2]

double operator*

(

const Momentum &

mom

)

const

Definition at line 120 of file Momentum.cpp.

operator*() [2/2]

Momentum operator*

(

double

c

)

const

Definition at line 127 of file Momentum.cpp.

operator*=() [1/2]

double operator*=

(

const Momentum &

)

operator*=() [2/2]

Momentum & operator*=

(

double

c

)

Definition at line 129 of file Momentum.cpp.

operator+()

Momentum operator+

(

const Momentum &

mom

)

const

Definition at line 100 of file Momentum.cpp.

operator+=()

Momentum & operator+=

(

const Momentum &

mom

)

Definition at line 104 of file Momentum.cpp.

operator-() [1/2]

Momentum operator-

(

)

const

Definition at line 109 of file Momentum.cpp.

operator-() [2/2]

Momentum operator-

(

const Momentum &

mom

)

const

Definition at line 111 of file Momentum.cpp.

operator-=()

Momentum & operator-=

(

const Momentum &

mom

)

Definition at line 115 of file Momentum.cpp.

operator==()

bool operator==

(

const Momentum &

oth

)

const

Definition at line 63 of file Momentum.cpp.

p()

double p

(

)

const

Definition at line 130 of file Momentum.h.

p2()

double p2

(

)

const

Definition at line 132 of file Momentum.h.

phi()

double phi

(

)

const

Definition at line 232 of file Momentum.cpp.

pt()

double pt

(

)

const

Definition at line 234 of file Momentum.cpp.

pt2()

double pt2

(

)

const

Definition at line 236 of file Momentum.cpp.

pVector()

std::array< double, 5 > pVector

(

)

const

Definition at line 206 of file Momentum.cpp.

px()

double px

(

)

const

Definition at line 112 of file Momentum.h.

py()

double py

(

)

const

Definition at line 116 of file Momentum.h.

pz()

double pz

(

)

const

Definition at line 120 of file Momentum.h.

rapidity()

double rapidity

(

)

const

Definition at line 246 of file Momentum.cpp.

rotatePhi()

Momentum & rotatePhi	(	double	phi,
		double	sign
	)

Definition at line 318 of file Momentum.cpp.

rotateThetaPhi()

Momentum & rotateThetaPhi	(	double	theta_,
		double	phi_
	)

Definition at line 324 of file Momentum.cpp.

setEnergy()

Momentum & setEnergy

(

double

e

)

Definition at line 172 of file Momentum.cpp.

setMass()

Momentum & setMass

(

double

m

)

Definition at line 177 of file Momentum.cpp.

setMass2()

Momentum & setMass2

(

double

m2

)

Definition at line 179 of file Momentum.cpp.

setP() [1/2]

Momentum & setP	(	double	px,
		double	py,
		double	pz
	)

Definition at line 183 of file Momentum.cpp.

setP() [2/2]

Momentum & setP	(	double	px,
		double	py,
		double	pz,
		double	e
	)

Definition at line 181 of file Momentum.cpp.

setPx()

Momentum & setPx

(

double

px

)

Definition at line 157 of file Momentum.cpp.

setPy()

Momentum & setPy

(

double

py

)

Definition at line 162 of file Momentum.cpp.

setPz()

Momentum & setPz

(

double

pz

)

Definition at line 167 of file Momentum.cpp.

theta()

double theta

(

)

const

Definition at line 230 of file Momentum.cpp.

threeProduct()

double threeProduct

(

const Momentum &

mom

)

const

Definition at line 138 of file Momentum.cpp.

transverse()

Momentum transverse

(

)

const

Definition at line 238 of file Momentum.cpp.

truncate()

Momentum & truncate

(

double

tolerance = 1.e-10

)

Definition at line 198 of file Momentum.cpp.

Friends And Related Symbol Documentation

operator*

Momentum operator* ( double  c, const Momentum &  mom  )

friend

Definition at line 134 of file Momentum.cpp.

operator<<

std::ostream & operator<< ( std::ostream &  os, const Momentum &  mom  )

friend

Definition at line 348 of file Momentum.cpp.