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SingletonFormFactor.cc
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// -*- C++ -*-
//
// This is the implementation of the non-inlined, non-templated member
// functions of the SingletonFormFactor class.
//
#include "SingletonFormFactor.h"
#include "ThePEG/Interface/ClassDocumentation.h"
#include "ThePEG/Interface/Parameter.h"
#include "ThePEG/Interface/ParVector.h"
#include "ThePEG/Persistency/PersistentOStream.h"
#include "ThePEG/Persistency/PersistentIStream.h"
using namespace Herwig;
using namespace ThePEG;
void SingletonFormFactor::doinit() throw(InitException) {
BaryonFormFactor::doinit();
if(numberOfFactors()!=_polemass.size())
throw InitException() << "Inconsistent parameters in SingletonFormFactor::doinit()"
<< Exception::abortnow;
// calculate the constants for the form-factors
int id0,id1;
_xi.resize(0);_NmM.resize(0);_mquark.resize(0);
for(unsigned int ix=0;ix<numberOfFactors();++ix) {
// id codes for the particles
particleID(ix,id0,id1);
if((abs(id0)==5122&&abs(id1)==4122)||(abs(id0)==5132&&abs(id1)==4132)||
(abs(id0)==5232&&abs(id1)==4232)) {
_mquark.push_back(_mcharm);
_xi.push_back(1.);
_NmM.push_back(1.);
}
else if((abs(id0)==5222&&abs(id1)==4222)||(abs(id0)==5212&&abs(id1)==4212)||
(abs(id0)==5112&&abs(id1)==4112)||(abs(id0)==5332&&abs(id1)==4332)||
(abs(id0)==5312&&abs(id1)==4312)||(abs(id0)==5322&&abs(id1)==4322)) {
_mquark.push_back(_mcharm);
_xi.push_back(-1./3.);
_NmM.push_back(1.);
}
else if(abs(id0)==4122&&abs(id1)==3122) {
_mquark.push_back(_mstrange);
_xi.push_back(1.);
_NmM.push_back(sqrt(2./3.)*sin(_thetalambda));
}
else if((abs(id0)==4222&&abs(id1)==3222)||(abs(id0)==4212&&abs(id1)==3212)||
(abs(id0)==4112&&abs(id1)==3112)) {
_mquark.push_back(_mstrange);
_xi.push_back(-1./3.);
_NmM.push_back(sqrt(2./3.)*cos(_thetasigma));
}
else if((abs(id0)==4132&&abs(id1)==3312)||(abs(id0)==4232&&abs(id1)==3322)) {
_mquark.push_back(_mstrange);
_xi.push_back(1.);
_NmM.push_back(1./sqrt(2.)*sin(_thetaxi));
}
else if((abs(id0)==4312&&abs(id1)==3322)||(abs(id0)==4322&&abs(id1)==3312)) {
_mquark.push_back(_mstrange);
_xi.push_back(-1./3.);
_NmM.push_back(1./sqrt(6.)*cos(_thetaxip));
}
else
throw InitException() << "Unknown mode in SingletonFormFactor::doinit()"
<< Exception::abortnow;
}
}
void SingletonFormFactor::persistentOutput(PersistentOStream & os) const {
os << ounit(_mcharm,GeV) << ounit(_mstrange,GeV) << _thetalambda << _thetasigma << _thetaxi
<< _thetaxip << ounit(_polemass,GeV) << _xi << _NmM << ounit(_mquark,GeV);
}
void SingletonFormFactor::persistentInput(PersistentIStream & is, int) {
is >> iunit(_mcharm,GeV) >> iunit(_mstrange,GeV) >> _thetalambda >> _thetasigma >> _thetaxi
>> _thetaxip >> iunit(_polemass,GeV) >> _xi >> _NmM >> iunit(_mquark,GeV);
}
ClassDescription<SingletonFormFactor> SingletonFormFactor::initSingletonFormFactor;
// Definition of the static class description member.
void SingletonFormFactor::Init() {
static ClassDocumentation<SingletonFormFactor> documentation
("The SingletonFormFactor class implements the"
" form-factors of PRD43, 2939 for the decay of spin-1/2 baryons"
" containing one heavy quark.");
static Parameter<SingletonFormFactor,Energy> interfaceCharmMass
("CharmMass",
"The mass of the charm quark",
&SingletonFormFactor::_mcharm, GeV, 1.8*GeV, 0.0*GeV, 10.0*GeV,
false, false, true);
static Parameter<SingletonFormFactor,Energy> interfaceStrangeMass
("StrangeMass",
"The mass of the strange quark",
&SingletonFormFactor::_mstrange, GeV, 0.51*GeV, 0.0*GeV, 10.0*GeV,
false, false, true);
static Parameter<SingletonFormFactor,double> interfaceThetaLambda
("ThetaLambda",
"The mixing angle for the Lambda",
&SingletonFormFactor::_thetalambda, 0.785398163, 0.0, 6.28318507,
false, false, true);
static Parameter<SingletonFormFactor,double> interfaceThetaSigma
("ThetaSigma",
"The mixing angle for the Sigma",
&SingletonFormFactor::_thetasigma, 0.785398163, 0.0, 6.28318507,
false, false, true);
static Parameter<SingletonFormFactor,double> interfaceThetaXi
("ThetaXi",
"The mixing angle for the Xi",
&SingletonFormFactor::_thetaxi, 0.785398163, 0.0, 6.28318507,
false, false, true);
static Parameter<SingletonFormFactor,double> interfaceThetaXiPrime
("ThetaXiPrime",
"The mixing angle for the Xi'",
&SingletonFormFactor::_thetaxip, 0.785398163, 0.0, 6.28318507,
false, false, true);
static ParVector<SingletonFormFactor,Energy> interfacePoleMass
("PoleMass",
"The mass for the energy dependence of the form-factors.",
&SingletonFormFactor::_polemass,
1.*GeV, 0, 0*GeV, -10.*GeV, 10.*GeV, false, false, true);
}
// form factor for spin-1/2 to spin-1/2
void SingletonFormFactor::
SpinHalfSpinHalfFormFactor(Energy2 q2,int iloc,int, int, Energy m0, Energy m1,
Complex & f1v,Complex & f2v,Complex & f3v,
Complex & f1a,Complex & f2a,Complex & f3a)
{
InvEnergy ratio(0.5/m0);
// all factors divided by sqrt(4.*m0*m1) normalisation
double gbar(m1*_xi[iloc]*_NmM[iloc]/_mquark[iloc]);
double abar(_xi[iloc]*_NmM[iloc]);
InvEnergy apbar(-ratio*(m1/_mquark[iloc]-1.)*_xi[iloc]*_NmM[iloc]);
InvEnergy ambar(apbar);
InvEnergy gpbar(-ratio*_NmM[iloc]*((_xi[iloc]*m1/_mquark[iloc]-1.)
+0.5*(m1-m0)/_mquark[iloc]*(1.-_xi[iloc])));
InvEnergy gmbar(-ratio*_NmM[iloc]*((_xi[iloc]*m1/_mquark[iloc]-1.)
+0.5*(m1+m0)/_mquark[iloc]*(1.-_xi[iloc])));
// energy dependence
double ymax((1.-m1/m0)); ymax *=ymax;
double yres(_polemass[iloc]/m0);yres *=yres;
double y(q2/m0/m0),efact((ymax-yres)/(y-yres));
f1v = efact*(gbar+(m0+m1)*gpbar);
f2v = efact*gpbar*(m0+m1);
f3v = efact*gmbar*(m0+m1);
f1a = efact*(-abar+(m0-m1)*apbar);
f2a =-efact*apbar*(m0+m1);
f3a =-efact*ambar*(m0+m1);
}
void SingletonFormFactor::dataBaseOutput(ofstream & output,bool header,
bool create) const
{
if(header){output << "update decayers set parameters=\"";}
if(create)
{output << "create Herwig::SingletonFormFactor " << fullName() << " \n ";}
output << "set " << fullName() << ":CharmMass " << _mcharm/GeV << " \n";
output << "set " << fullName() << ":StrangeMass " << _mstrange/GeV << " \n";
output << "set " << fullName() << ":ThetaLambda " << _thetalambda << " \n";
output << "set " << fullName() << ":ThetaSigma " << _thetasigma << " \n";
output << "set " << fullName() << ":ThetaXi " << _thetaxi << " \n";
output << "set " << fullName() << ":ThetaXiPrime " << _thetaxip << " \n";
for(unsigned int ix=0;ix<_polemass.size();++ix)
{
if(ix<initialModes())
{output << "set " << fullName() << ":PoleMass " << ix << " "
<< _polemass[ix]/GeV << endl;}
else
{output << "insert " << fullName() << ":PoleMass "<< ix << " "
<< _polemass[ix]/GeV << endl;}
}
BaryonFormFactor::dataBaseOutput(output,false,false);
if(header){output << "\n\" where BINARY ThePEGName=\"" << fullName() << "\";" << endl;}
}

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