hephysics.particle

Class LParticle

java.lang.Object

hephysics.vec.HepLorentzVector

hephysics.particle.LParticle

All Implemented Interfaces:

java.io.Serializable, java.lang.Comparable<LParticle>

Direct Known Subclasses:

HEParticle

public class LParticle
extends HepLorentzVector
implements java.lang.Comparable<LParticle>, java.io.Serializable

A class representing a Lorentz particle. It is based on four-Lorentz vector and extends HepLorentzVector. A particle can be represented by either (px,py,pz,E) or (x,y,z,time). In addition, you can define name, mass,charge and a parent particle as an object.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
LParticle() Define a dummy particle.
LParticle(double px, double py, double pz) Define a 3-momentum or X,Y,Z position.
LParticle(double px, double py, double pz, double energy) Define a particle in momentum or 4-space time.
LParticle(double px, double py, double pz, double energy, double mass) Define a particle in momentum or coordinate space.
LParticle(java.lang.String name) Define a particle with a name.
LParticle(java.lang.String name, double mass) Define a particle with a name and mass.
LParticle(java.lang.String name, double px, double py, double pz, double energy, double mass) Define a Lorentz particle in momentum or coordinate space.

Method Summary

Modifier and Type	Method and Description
double	abs() Magnitude
void	add(LParticle another) Add 2 particle
double	angle(LParticle momentum) Angle between 2 vectors in rad
void	boost(LParticle parent) Lorentz Boost
double	calcMass() Get calculated mass as sqrt(e*e-px**2-py**2-pz**2)
int	compareTo(LParticle o) Comparator.
LParticle	copy() Make an exact copy of this particle
void	dividePxPyPzE(double scale) Divide all components (Px,Py,Px,E) by a factor C.
void	doc() Show online documentation.
double	getCharge() Get charge
double	getMass() Get a mass
java.lang.String	getName() Get a name
LParticle	getParent() Get a parent particle
Hep3Vector	getV3() Get a 3-vector woth (Px,Py,Pz) or (X,Y,Z)
int	hashCode() Get a hash code
double	mass() Get a mass
void	print() Print particle
void	scalePxPyPzE(double scale) Scale all components (Px,Py,Px,E) by a factor C.
void	scaleXYZT(double scale) Scale all components (X,Y,Z,T) by a factor This means all components are multiplied by this factor.
void	setCharge(double charge) Set charge
void	setMass(double mass) Set a mass
void	setParent(LParticle parent) Set a parent particle
void	setPtEtaPhiE(double pt, double eta, double phi, double e) Set 4-momentum of a particle using transverse momentum (pt), pseudorapidity (Eta) and azimuthal angle (phi) and energy.
void	setPtEtaPhiM(double pt, double eta, double phi, double m) Set 4-momentum of a particle using transverse momentum (pt), pseudorapidity (eta) and azimuthal angle (phi) and mass (m).
void	setPxPyPz(double px, double py, double pz) Set Px,Py,Pz (or x,y,z)
void	setPxPyPzE(double px, double py, double pz, double e) Set Px,Py,Pz and energy of a particle
void	setThetaPhiP(double theta, double phi, double P) Set HepLorentzVector using theta angle, phi and total momentum P.
void	setXYZT(double x, double y, double z, double t) Set x,y,z and time for a particle (vertex position)
java.lang.String	toString() Convert to string
void	twoBodyDecay(LParticle prod1, LParticle prod2, boolean randomRotate) Evaluates 4-vector of decay product in the rest frame of parent.

Methods inherited from class hephysics.vec.HepLorentzVector

add, add, angle, boost, boost, boost, centerOfMass, cosTheta, dot, e, equals, et, et2, getE, getEta, getT, invariantMass, invariantMass2, isLightlike, isSpacelike, m, m2, mag, mag2, mt, mt2, mult, neg, neg, perp, perp2, phi, pseudoRapidity, px, py, pz, rapidity, restMass2, setE, setPx, setPy, setPz, setT, setV3, setV3, setX, setY, setZ, skp, sub, t, theta, v3, x, y, z

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

LParticle

public LParticle()

Define a dummy particle. Set Px,Py,Pz,mass to zero.

LParticle

public LParticle(java.lang.String name)

Define a particle with a name. Set Px,Py,Pz,mass to zero.

Parameters:

name - particle name

LParticle

public LParticle(java.lang.String name,
                 double mass)

Define a particle with a name and mass. Set Px,Py,Pz to zero.

Parameters:

name - particle name

mass - mass

LParticle

public LParticle(double px,
                 double py,
                 double pz)

Define a 3-momentum or X,Y,Z position. Energy and mass are set to 0.

Parameters:

px - Px (or X_)

py - Py (or Y)

pz - Pz (or Z)

LParticle

public LParticle(double px,
                 double py,
                 double pz,
                 double energy,
                 double mass)

Define a particle in momentum or coordinate space.

Parameters:

px - Px (or X position)

py - Py (or Y position)

pz - Pz (or Z position)

energy - energy (or time)

mass - mass

LParticle

public LParticle(double px,
                 double py,
                 double pz,
                 double energy)

Define a particle in momentum or 4-space time. Mass is set to 0

Parameters:

px - Px or X position

py - Py or Y position

pz - Pz or Z position

energy - energy or time

LParticle

public LParticle(java.lang.String name,
                 double px,
                 double py,
                 double pz,
                 double energy,
                 double mass)

Define a Lorentz particle in momentum or coordinate space.

Parameters:

name - Name of particle

px - px (or X)

py - py (or Y)

pz - pz (or Z)

energy - energy or time

mass - mass

Method Detail

setPxPyPz

public void setPxPyPz(double px,
                      double py,
                      double pz)

Set Px,Py,Pz (or x,y,z)

Parameters:

px -

py -

pz -

setPxPyPzE

public void setPxPyPzE(double px,
                       double py,
                       double pz,
                       double e)

Set Px,Py,Pz and energy of a particle

Parameters:

px - Px momentum

py - Py momentum

pz - Pz momentum

e - energy

setXYZT

public void setXYZT(double x,
                    double y,
                    double z,
                    double t)

Set x,y,z and time for a particle (vertex position)

Parameters:

x - X position

y - Y position

z - Z position

t - time

setParent

public void setParent(LParticle parent)

Set a parent particle

Parameters:

parent - parent particle

scalePxPyPzE

public void scalePxPyPzE(double scale)

Scale all components (Px,Py,Px,E) by a factor C. Keep mass unchanged. This means all components are multiplied by this factor.

Parameters:

scale - factor used to multiply Px,Py,Pz,E components.

scaleXYZT

public void scaleXYZT(double scale)

Scale all components (X,Y,Z,T) by a factor This means all components are multiplied by this factor.

Parameters:

scale - factor used to multiply X,Y,Z,T components.

dividePxPyPzE

public void dividePxPyPzE(double scale)

Divide all components (Px,Py,Px,E) by a factor C. Useful for varints (integer) representation.

Parameters:

scale - factor used to divide Px,Py,Pz,E

getParent

public LParticle getParent()

Get a parent particle

Returns:

parent

add

public void add(LParticle another)

Add 2 particle

Parameters:

another - particle to be edded

getMass

public double getMass()

Get a mass

Returns:

mass

mass

public double mass()

Get a mass

Returns:

mass

getName

public java.lang.String getName()

Get a name

Returns:

name

getV3

public Hep3Vector getV3()

Get a 3-vector woth (Px,Py,Pz) or (X,Y,Z)

Overrides:

getV3 in class HepLorentzVector

Returns:

3-vector

setMass

public void setMass(double mass)

Set a mass

Parameters:

mass - Mass

hashCode

public int hashCode()

Get a hash code

Overrides:

hashCode in class HepLorentzVector

setThetaPhiP

public void setThetaPhiP(double theta,
                         double phi,
                         double P)

Set HepLorentzVector using theta angle, phi and total momentum P. e = sqrt(P*P + mass*mass);
pX = P*sin(theta)*cos(phi);
pY = P*sin(theta)*sin(phi);
pZ = P*cos(theta);

Parameters:

theta - theta

phi - phi

P - momentum

setPtEtaPhiE

public void setPtEtaPhiE(double pt,
                         double eta,
                         double phi,
                         double e)

Set 4-momentum of a particle using transverse momentum (pt), pseudorapidity (Eta) and azimuthal angle (phi) and energy.

Parameters:

pt - transverse momentum of a particle.

eta - eta (pseudorapidity) .

phi - azimuthal angle

e - energy

setPtEtaPhiM

public void setPtEtaPhiM(double pt,
                         double eta,
                         double phi,
                         double m)

Set 4-momentum of a particle using transverse momentum (pt), pseudorapidity (eta) and azimuthal angle (phi) and mass (m). In this case, the energy is Math.sqrt(px*px+py*py+pz*pz-m*m).

Parameters:

pt - transverse momentum of a particle.

eta - eta (pseudorapidity) .

phi - azimuthal angle

m - mass

abs

public double abs()

Magnitude

Returns:

setCharge

public void setCharge(double charge)

Set charge

Parameters:

charge - charge

getCharge

public double getCharge()

Get charge

Returns:

angle

public double angle(LParticle momentum)

Angle between 2 vectors in rad

Parameters:

momentum - parent particle

Returns:

angle in rad

calcMass

public double calcMass()

Get calculated mass as sqrt(e*e-px**2-py**2-pz**2)

Returns:

twoBodyDecay

public void twoBodyDecay(LParticle prod1,
                         LParticle prod2,
                         boolean randomRotate)

Evaluates 4-vector of decay product in the rest frame of parent.

Parameters:

prod1 - first decay product

prod2 - second decay product

randomRotate - is Phi randomly rotated?

boost

public void boost(LParticle parent)

Lorentz Boost

Parameters:

parent - parent particle

toString

public java.lang.String toString()

Convert to string

Overrides:

toString in class HepLorentzVector

copy

public LParticle copy()

Make an exact copy of this particle

Overrides:

copy in class HepLorentzVector

Returns:

new copy

print

public void print()

Print particle

doc

public void doc()

Show online documentation.

compareTo

public int compareTo(LParticle o)

Comparator. using perp2 for comparison (in increasing order)

Specified by:

compareTo in interface java.lang.Comparable<LParticle>

Parameters:

o -

Returns: