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// -*- C++ -*-
//
// VectorWaveFunction.cc is a part of ThePEG - Toolkit for HEP Event Generation
// Copyright (C) 2003-2011 Peter Richardson, Leif Lonnblad
//
// ThePEG is licenced under version 2 of the GPL, see COPYING for details.
// Please respect the MCnet academic guidelines, see GUIDELINES for details.
//
//
// This is the implementation of the non-inlined, non-templated member
// functions of the VectorWaveFunction class.
//
// Author: Peter Richardson
//
#include "VectorWaveFunction.h"
using namespace ThePEG;
using namespace ThePEG::Helicity;
// calculate the Wavefunction
void VectorWaveFunction::calculateWaveFunction(unsigned int ihel,VectorPhase vphase) {
Direction dir=direction();
if(dir==intermediate)
throw ThePEG::Helicity::HelicityConsistencyError()
<< "In VectorWaveFunction::calcluateWaveFunction "
<< "particle must be incoming or outgoing not intermediate"
<< Exception::abortnow;
// check a valid helicity combination
if(ihel==0 || ihel==2||(ihel==1&&mass()>ZERO)) {
int jhel=ihel-1;
// extract the momentum components
double fact=-1.; if(dir==incoming){fact=1.;}
Energy ppx=fact*px(),ppy=fact*py(),ppz=fact*pz(),pee=fact*e(),pmm=mass();
// calculate some kinematic quantites;
Energy2 pt2 = ppx*ppx+ppy*ppy;
Energy pabs = sqrt(pt2+ppz*ppz);
Energy pt = sqrt(pt2);
// overall phase of the vector
Complex phase;
if(vphase==vector_phase) {
if(pt==ZERO || ihel==1) phase = 1.;
else if(ihel==0) phase = Complex(ppx/pt,-fact*ppy/pt);
else phase = Complex(ppx/pt, fact*ppy/pt);
}
else phase = 1.;
if(ihel!=1) phase = phase/sqrt(2.);
// first the +/-1 helicity states
if(ihel!=1) {
// first the no pt case
if(pt==ZERO) {
double sgnz;
sgnz = ppz<ZERO ? -1. : 1.;
_wf.setX(-complex<double>(jhel)*phase);
_wf.setY(sgnz*phase*complex<double>(0,-fact));
_wf.setZ(0.);
_wf.setT(0.);
}
else {
InvEnergy opabs=1./pabs;
InvEnergy opt =1./pt;
_wf.setX(phase*complex<double>(-jhel*ppz*ppx*opabs*opt, fact*ppy*opt));
_wf.setY(phase*complex<double>(-jhel*ppz*ppy*opabs*opt,-fact*ppx*opt));
_wf.setZ(double(jhel*pt*opabs)*phase);
_wf.setT(0.);
}
}
// 0 component for massive vectors
else {
if(pabs==ZERO) {
_wf.setX(0.);
_wf.setY(0.);
_wf.setZ(1.);
_wf.setT(0.);
}
else {
InvEnergy empabs=pee/pmm/pabs;
_wf.setX(double(empabs*ppx));
_wf.setY(double(empabs*ppy));
_wf.setZ(double(empabs*ppz));
_wf.setT(double(pabs/pmm));
}
}
}
// special return the momentum as a check of gauge invariance
else if(ihel==10) {
_wf.setX(double(px()/MeV));
_wf.setY(double(py()/MeV));
_wf.setZ(double(pz()/MeV));
_wf.setT(double(e()/MeV));
}
// issue warning and return zero
else {
ThePEG::Helicity::HelicityConsistencyError()
<< "Invalid Helicity = " << ihel << " requested for Vector "
<< particle()->PDGName() << Exception::abortnow;
_wf.setX(0.);_wf.setY(0.);_wf.setZ(0.);_wf.setT(0.);
}
}
void VectorWaveFunction::
calculateWaveFunctions(vector<LorentzPolarizationVector> & waves,
tPPtr particle,Direction dir,bool massless,
VectorPhase phase) {
tVectorSpinPtr inspin = !particle->spinInfo() ? tVectorSpinPtr() :
dynamic_ptr_cast<tVectorSpinPtr>(particle->spinInfo());
waves.resize(3);
if(inspin) {
if(dir==outgoing) {
for(unsigned int ix=0;ix<3;++ix)
waves[ix]=inspin->getProductionBasisState(ix);
}
else {
inspin->decay();
for(unsigned int ix=0;ix<3;++ix)
waves[ix]=inspin->getDecayBasisState(ix);
}
}
else {
assert(!particle->spinInfo());
VectorWaveFunction wave(particle->momentum(),particle->dataPtr(),0,
dir,phase);
for(unsigned int ix=0;ix<3;++ix) {
if(massless&&ix==1) {
waves[ix] = LorentzPolarizationVector();
}
else {
if(ix!=0) wave.reset(ix);
waves[ix] = wave.wave();
}
}
}
}
void VectorWaveFunction::
calculateWaveFunctions(vector<VectorWaveFunction> & waves,
tPPtr particle, Direction dir, bool massless,
VectorPhase phase) {
tVectorSpinPtr inspin = !particle->spinInfo() ? tVectorSpinPtr() :
dynamic_ptr_cast<tVectorSpinPtr>(particle->spinInfo());
waves.resize(3);
if(inspin) {
if(dir==outgoing) {
for(unsigned int ix=0;ix<3;++ix)
waves[ix]=VectorWaveFunction(particle->momentum(),
particle->dataPtr(),
inspin->getProductionBasisState(ix),dir);
}
else {
inspin->decay();
for(unsigned int ix=0;ix<3;++ix)
waves[ix]=VectorWaveFunction(particle->momentum(),
particle->dataPtr(),
inspin->getDecayBasisState(ix),dir);
}
}
else {
assert(!particle->spinInfo());
VectorWaveFunction wave(particle->momentum(),particle->dataPtr(),0,
dir,phase);
for(unsigned int ix=0;ix<3;++ix) {
if(massless&&ix==1) {
waves[ix] = VectorWaveFunction(particle->momentum(),
particle->dataPtr(),dir);
}
else {
if(ix!=0) wave.reset(ix);
waves[ix] = wave;
}
}
}
}
void VectorWaveFunction::
calculateWaveFunctions(vector<LorentzPolarizationVector> & waves,
RhoDMatrix & rho,tPPtr particle,
Direction dir,bool massless,
VectorPhase phase) {
tVectorSpinPtr inspin = !particle->spinInfo() ? tVectorSpinPtr() :
dynamic_ptr_cast<tVectorSpinPtr>(particle->spinInfo());
waves.resize(3);
if(inspin) {
if(dir==outgoing) {
for(unsigned int ix=0;ix<3;++ix)
waves[ix]=inspin->getProductionBasisState(ix);
rho = RhoDMatrix(PDT::Spin1);
}
else {
inspin->decay();
for(unsigned int ix=0;ix<3;++ix)
waves[ix]=inspin->getDecayBasisState(ix);
rho = inspin->rhoMatrix();
}
}
else {
assert(!particle->spinInfo());
VectorWaveFunction wave(particle->momentum(),particle->dataPtr(),0,
dir,phase);
for(unsigned int ix=0;ix<3;++ix) {
if(massless&&ix==1) {
waves[ix] = LorentzPolarizationVector();
}
else {
if(ix!=0) wave.reset(ix);
waves[ix] = wave.wave();
}
}
rho = RhoDMatrix(PDT::Spin1);
}
}
void VectorWaveFunction::
calculateWaveFunctions(vector<VectorWaveFunction> & waves,
RhoDMatrix & rho,
tPPtr particle, Direction dir,bool massless,
VectorPhase phase) {
tVectorSpinPtr inspin = !particle->spinInfo() ? tVectorSpinPtr() :
dynamic_ptr_cast<tVectorSpinPtr>(particle->spinInfo());
waves.resize(3);
if(inspin) {
if(dir==outgoing) {
for(unsigned int ix=0;ix<3;++ix)
waves[ix]=VectorWaveFunction(particle->momentum(),
particle->dataPtr(),
inspin->getProductionBasisState(ix),dir);
rho = RhoDMatrix(PDT::Spin1);
}
else {
inspin->decay();
for(unsigned int ix=0;ix<3;++ix)
waves[ix]=VectorWaveFunction(particle->momentum(),
particle->dataPtr(),
inspin->getDecayBasisState(ix),dir);
rho = inspin->rhoMatrix();
}
}
else {
assert(!particle->spinInfo());
VectorWaveFunction wave(particle->momentum(),particle->dataPtr(),0,
dir,phase);
for(unsigned int ix=0;ix<3;++ix) {
if(massless&&ix==1) {
waves[ix] = VectorWaveFunction(particle->momentum(),
particle->dataPtr(),dir);
}
else {
if(ix!=0) wave.reset(ix);
waves[ix] = wave;
}
}
rho = RhoDMatrix(PDT::Spin1);
}
}
void VectorWaveFunction::
constructSpinInfo(const vector<LorentzPolarizationVector> & waves,
tPPtr part,Direction dir, bool time,bool ) {
assert(waves.size()==3);
tVectorSpinPtr inspin = !part->spinInfo() ? tVectorSpinPtr() :
dynamic_ptr_cast<tVectorSpinPtr>(part->spinInfo());
if(inspin) {
for(unsigned int ix=0;ix<3;++ix)
if(dir==outgoing) inspin->setBasisState(ix,waves[ix]);
else inspin->setDecayState(ix,waves[ix]);
}
else {
VectorSpinPtr temp = new_ptr(VectorSpinInfo(part->momentum(),time));
part->spinInfo(temp);
for(unsigned int ix=0;ix<3;++ix)
if(dir==outgoing) temp->setBasisState(ix,waves[ix]);
else temp->setDecayState(ix,waves[ix]);
}
}
void VectorWaveFunction::
constructSpinInfo(const vector<VectorWaveFunction> & waves,
tPPtr part,Direction dir, bool time,bool ) {
assert(waves.size()==3);
tVectorSpinPtr inspin = !part->spinInfo() ? tVectorSpinPtr() :
dynamic_ptr_cast<tVectorSpinPtr>(part->spinInfo());
if(inspin) {
for(unsigned int ix=0;ix<3;++ix)
if(dir==outgoing) inspin->setBasisState(ix,waves[ix].wave());
else inspin->setDecayState(ix,waves[ix].wave());
}
else {
VectorSpinPtr temp = new_ptr(VectorSpinInfo(part->momentum(),time));
part->spinInfo(temp);
for(unsigned int ix=0;ix<3;++ix)
if(dir==outgoing) temp->setBasisState(ix,waves[ix].wave());
else temp->setDecayState(ix,waves[ix].wave());
}
}
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