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SSNNPVertex.cc
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// -*- C++ -*-
//
// SSNNPVertex.cc is a part of Herwig++ - A multi-purpose Monte Carlo event generator
// Copyright (C) 2002-2011 The Herwig Collaboration
//
// Herwig++ 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 SSNNPVertex class.
//
#include "SSNNPVertex.h"
#include "ThePEG/Interface/Switch.h"
#include "ThePEG/Interface/ClassDocumentation.h"
#include "ThePEG/Utilities/DescribeClass.h"
#include "ThePEG/Persistency/PersistentOStream.h"
#include "ThePEG/Persistency/PersistentIStream.h"
#include "Herwig++/Models/Susy/MixingMatrix.h"
#include "ThePEG/PDT/EnumParticles.h"
#include "Herwig++/Looptools/clooptools.h"
#include "Herwig++/Utilities/Maths.h"
using namespace ThePEG::Helicity;
using namespace Herwig;
SSNNPVertex::SSNNPVertex() : _includeOnShell(false), _realIntegral(false),
_sw(0.), _cw(0.), _id1last(0),
_id2last(0), _q2last(ZERO), _couplast(0.),
_leftlast(ZERO), _rightlast(ZERO) {
orderInGem(3);
orderInGs(0);
}
void SSNNPVertex::doinit() {
Looptools::ltini();
int ineu[5] = {1000022,1000023,1000025,1000035,1000045};
for(unsigned int i = 0; i < 5; ++i) {
for(unsigned int j = 0; j < 5; ++j) {
addToList(ineu[i], ineu[j], 22);
}
}
GeneralFFVVertex::doinit();
tMSSMPtr theSS = dynamic_ptr_cast<tMSSMPtr>(generator()->standardModel());
if(!theSS)
throw InitException() << "SSNNPVertex::doinit() - "
<< "The model pointer is null."
<< Exception::abortnow;
_theN = theSS->neutralinoMix();
_theU = theSS->charginoUMix();
_theV = theSS->charginoVMix();
if(!_theN || !_theU || ! _theV)
throw InitException() << "SSNNPVertex::doinit - The neutralino "
<< "mixing matrix pointer is null."
<< Exception::abortnow;
_sw = sqrt(sin2ThetaW());
_cw = sqrt(1 - _sw*_sw);
_mw = getParticleData(ParticleID::Wplus)->mass();
double tb = theSS->tanBeta();
_sb = tb/sqrt(1 + sqr(tb));
_cb = sqrt(1 - sqr(_sb));
_stop = theSS->stopMix();
_sbot = theSS->sbottomMix();
_stau = theSS->stauMix();
Looptools::ltexi();
}
void SSNNPVertex::dofinish() {
Looptools::ltexi();
GeneralFFVVertex::dofinish();
}
void SSNNPVertex::doinitrun() {
Looptools::ltini();
GeneralFFVVertex::doinitrun();
}
void SSNNPVertex::persistentOutput(PersistentOStream & os) const {
os << _sw << _cw << _theN << ounit(_mw,GeV) << _sb << _cb
<< _stop << _sbot << _stau << _theU << _theV << _includeOnShell
<< _realIntegral;
}
void SSNNPVertex::persistentInput(PersistentIStream & is, int) {
is >> _sw >> _cw >> _theN >> iunit(_mw,GeV) >> _sb >> _cb
>> _stop >> _sbot >> _stau >> _theU >> _theV >> _includeOnShell
>> _realIntegral;
}
// The following static variable is needed for the type
// description system in ThePEG.
DescribeClass<SSNNPVertex,Helicity::GeneralFFVVertex>
describeSSNNPVertex("Herwig::SSNNPVertex", "HwSusy.so");
void SSNNPVertex::Init() {
static ClassDocumentation<SSNNPVertex> documentation
("The loop-mediated coupling of the photon to a pair of neutralinos");
static Switch<SSNNPVertex,bool> interfaceIncludeOnShellIntermediates
("IncludeOnShellIntermediates",
"Whether or not to include on-shell intermediate states",
&SSNNPVertex::_includeOnShell, false, false, false);
static SwitchOption interfaceIncludeOnShellIntermediatesYes
(interfaceIncludeOnShellIntermediates,
"Yes",
"Include them",
true);
static SwitchOption interfaceIncludeOnShellIntermediatesNo
(interfaceIncludeOnShellIntermediates,
"No",
"Don't incldue them",
false);
static Switch<SSNNPVertex,bool> interfaceRealIntegral
("RealIntegral",
"Only include the real parts of the integrals",
&SSNNPVertex::_realIntegral, false, false, false);
static SwitchOption interfaceRealIntegralYes
(interfaceRealIntegral,
"Yes",
"Only include the real part",
true);
static SwitchOption interfaceRealIntegralNo
(interfaceRealIntegral,
"No",
"Don't include the real part",
false);
}
void SSNNPVertex::setCoupling(Energy2 q2, tcPDPtr part1,
#ifndef NDEBUG
tcPDPtr part2,tcPDPtr part3) {
#else
tcPDPtr part2,tcPDPtr) {
#endif
int o[2]={1,0};
long in1 = part1->id();
long in2 = part2->id();
Energy Mj = part1->mass();
Energy Mi = part2->mass();
// checks of the particle ids
assert(part3->id()==ParticleID::gamma);
assert(in1 == ParticleID::SUSY_chi_10 || in1 == ParticleID::SUSY_chi_20 ||
in1 == ParticleID::SUSY_chi_30 || in1 == ParticleID::SUSY_chi_40 ||
in1 == 1000045 );
assert(in2 == ParticleID::SUSY_chi_10 || in2 == ParticleID::SUSY_chi_20 ||
in2 == ParticleID::SUSY_chi_30 || in2 == ParticleID::SUSY_chi_40 ||
in2 == 1000045 );
// normal couplings are zero
setLeft (0.);
setRight(0.);
if(in1==in2) {
_leftlast = ZERO;
_rightlast = ZERO;
setLeftSigma (_leftlast );
setRightSigma(_rightlast);
return;
}
if(q2 != _q2last || _couplast==0.) {
_q2last = q2;
_couplast = sqr(weakCoupling(q2))*
electroMagneticCoupling(q2)/32./sqr(Constants::pi);
}
if(in1 != _id1last || in2 != _id2last) {
_leftlast = ZERO;
_rightlast = ZERO;
_id1last = in1;
_id2last = in2;
unsigned int neu1(in1 - 1000022), neu2(in2 - 1000022);
if(neu1 > 1) neu1 = (in1-1000005)/10;
if(neu2 > 1) neu2 = (in2-1000005)/10;
Complex n1prime[2] = { (*_theN)(neu2,0)*_cw + (*_theN)(neu2,1)*_sw ,
(*_theN)(neu1,0)*_cw + (*_theN)(neu1,1)*_sw };
Complex n2prime[2] = { (*_theN)(neu2,1)*_cw - (*_theN)(neu2,0)*_sw ,
(*_theN)(neu1,1)*_cw - (*_theN)(neu1,0)*_sw };
// sfermion/fermion loops
for(long iferm=1;iferm<16;++iferm) {
if(iferm==7) iferm=11;
if(iferm%2==0&&iferm>11) ++iferm;
tcPDPtr smf = getParticleData(iferm);
Energy mf = smf->mass();
double qf = smf->charge()/eplus;
double y = 0.5*mf/_mw;
Complex bracketl[2] = { qf*_sw*( conj(n1prime[0]) - _sw*conj(n2prime[0])/_cw ) ,
qf*_sw*( conj(n1prime[1]) - _sw*conj(n2prime[1])/_cw ) };
double lambda(0.);
//neutralino mixing element
Complex nlf[2]={0.,0.};
if( iferm % 2 == 0 ) {
y /= _sb;
lambda = -0.5 + qf*sqr(_sw);
nlf[0] = (*_theN)(neu2,3);
nlf[1] = (*_theN)(neu1,3);
}
else {
y /= _cb;
lambda = 0.5 + qf*sqr(_sw);
nlf[0] = (*_theN)(neu2,2);
nlf[1] = (*_theN)(neu1,2);
}
Complex bracketr[2] = { _sw*qf*n1prime[0] - n2prime[0]*lambda/_cw ,
_sw*qf*n1prime[1] - n2prime[1]*lambda/_cw };
for(long iy=0;iy<2;++iy) {
long isf = 1000000*(1+iy)+iferm;
Energy msf = getParticleData(isf)->mass();
if(!_includeOnShell&&(mf+msf<Mj||mf+msf<Mi)) continue;
Complex g[2][2];
Complex ma1(0.), ma2(0.);
// heavy fermions
if( iferm == 5 || iferm == 6 || iferm == 15 ) {
if( iferm == 5 ) {
ma1 = (*_sbot)(iy,0);
ma2 = (*_sbot)(iy,1);
}
else if( iferm == 6 ) {
ma1 = (*_stop)(iy,0);
ma2 = (*_stop)(iy,1);
}
else {
ma1 = (*_stau)(iy,0);
ma2 = (*_stau)(iy,1);
}
}
else if(iy==0) {
ma1 = 1.;
}
else {
ma2 = 1.;
}
for(unsigned int ix=0;ix<2;++ix) {
g[ix][0] = y*conj(nlf[ix])*ma1 - ma2*bracketl[ix];
g[ix][1] = y*nlf[ix]*ma2 + ma1*bracketr[ix];
}
swap(g[0][0],g[0][1]);
complex<InvEnergy2> I,J,K,I2;
loopIntegrals(Mi,Mj,msf,mf,I,J,K,I2);
complex<InvEnergy> coup[2];
for(unsigned int ix=0;ix<2;++ix) {
coup[ix] = Mj*(I2-K)*(g[0][ix]*g[1][o[ix]]-conj(g[0][o[ix]]*g[1][ix]))
+Mi*K*(g[0][o[ix]]*g[1][ix]-conj(g[0][ix]*g[1][o[ix]]))
+mf*I*(g[0][ix]*g[1][ix]-conj(g[0][o[ix]]*g[1][o[ix]]));
}
double fact = 4.*qf;
if(iferm<=6) fact *=3.;
_leftlast += fact*coup[0];
_rightlast += fact*coup[1];
}
}
// the chargino W contribution
for(unsigned int ic=0;ic<2;++ic) {
long id = ic==0 ?
ParticleID::SUSY_chi_1plus : ParticleID::SUSY_chi_2plus;
Energy Mk = getParticleData(id)->mass();
if(!_includeOnShell&&(Mk+_mw<Mj||Mk+_mw<Mi)) continue;
complex<InvEnergy2> I,J,K,I2;
loopIntegrals(Mi,Mj,_mw,Mk,I,J,K,I2);
Complex g[2][2];
for(unsigned int ix=0;ix<2;++ix) {
unsigned int in = ix==0 ? neu2 : neu1;
g[ix][0] =
conj((*_theN)(in, 1))*(*_theV)(ic, 0) -
conj((*_theN)(in, 3))*(*_theV)(ic, 1)/sqrt(2);
g[ix][1] =
(*_theN)(in, 1)*conj((*_theU)(ic, 0)) +
(*_theN)(in, 2)*conj((*_theU)(ic, 1))/sqrt(2);
}
complex<InvEnergy> coup[2];
for(unsigned int ix=0;ix<2;++ix) {
coup[ix] =
Mj*(I2-J-K)*(g[0][o[ix]]*g[1][o[ix]]-conj(g[0][ix]*g[1][ix]))-
Mi*(J-K)*(g[0][ix]*g[1][ix]-conj(g[0][o[ix]]*g[1][o[ix]]))+
2.*Mk*J*(g[0][o[ix]]*g[1][ix]-conj(g[0][ix]*g[1][o[ix]]));
}
_leftlast += 4.*coup[0];
_rightlast += 4.*coup[1];
}
// the chargino charged higgs contribution
Energy mh = getParticleData(ParticleID::Hplus)->mass();
for(unsigned int ic=0;ic<2;++ic) {
long id = ic==0 ?
ParticleID::SUSY_chi_1plus : ParticleID::SUSY_chi_2plus;
Energy Mk = getParticleData(id)->mass();
if(!_includeOnShell&&(Mk+mh<Mj||Mk+mh<Mi)) continue;
complex<InvEnergy2> I,J,K,I2;
loopIntegrals(Mi,Mj,mh,Mk,I,J,K,I2);
Complex g[2][2];
for(unsigned int ix=0;ix<2;++ix) {
unsigned int in = ix==0 ? neu2 : neu1;
g[ix][0] = (*_theN)(in, 3)*(*_theV)(ic,0)
+ ((*_theN)(in,1) + (*_theN)(in,0)*_sw/_cw)*
(*_theV)(ic,1)/sqrt(2);
g[ix][0] *= _cb;
g[ix][1] = conj((*_theN)(in, 2)*(*_theU)(ic,0)
- ((*_theN)(in,1) + (*_theN)(in,0)*_sw/_cw)*
(*_theU)(ic,1)/sqrt(2));
g[ix][1] *= _sb;
}
swap(g[1][0],g[1][1]);
complex<InvEnergy> coup[2];
for(unsigned int ix=0;ix<2;++ix) {
coup[ix] = Mj*(I2-K)*(g[0][ix]*g[1][o[ix]]-conj(g[0][o[ix]]*g[1][ix]))
+Mi*K*(g[0][o[ix]]*g[1][ix]-conj(g[0][ix]*g[1][o[ix]]))
+Mk*I*(g[0][ix]*g[1][ix]-conj(g[0][o[ix]]*g[1][o[ix]]));
}
_leftlast += 2.*coup[0];
_rightlast += 2.*coup[1];
}
// the chargino goldstone contribution
for(unsigned int ic=0;ic<2;++ic) {
long id = ic==0 ?
ParticleID::SUSY_chi_1plus : ParticleID::SUSY_chi_2plus;
Energy Mk = getParticleData(id)->mass();
if(!_includeOnShell&&(Mk+_mw<Mj||Mk+_mw<Mi)) continue;
complex<InvEnergy2> I,J,K,I2;
loopIntegrals(Mi,Mj,_mw,Mk,I,J,K,I2);
Complex g[2][2];
for(unsigned int ix=0;ix<2;++ix) {
unsigned int in = ix==0 ? neu2 : neu1;
g[ix][0] = (*_theN)(in, 3)*(*_theV)(ic,0)
+ ((*_theN)(in,1) + (*_theN)(in,0)*_sw/_cw)*
(*_theV)(ic,1)/sqrt(2);
g[ix][0] *=-_sb;
g[ix][1] = conj((*_theN)(in, 2)*(*_theU)(ic,0)
- ((*_theN)(in,1) + (*_theN)(in,0)*_sw/_cw)*
(*_theU)(ic,1)/sqrt(2));
g[ix][1] *= _cb;
}
swap(g[1][0],g[1][1]);
complex<InvEnergy> coup[2];
for(unsigned int ix=0;ix<2;++ix) {
coup[ix] = Mj*(I2-K)*(g[0][ix]*g[1][o[ix]]-conj(g[0][o[ix]]*g[1][ix]))
+Mi*K*(g[0][o[ix]]*g[1][ix]-conj(g[0][ix]*g[1][o[ix]]))
+Mk*I*(g[0][ix]*g[1][ix]-conj(g[0][o[ix]]*g[1][o[ix]]));
}
_leftlast += 2.*coup[0];
_rightlast += 2.*coup[1];
}
}
norm(_couplast);
setLeftSigma ( _leftlast);
setRightSigma(_rightlast);
}
void SSNNPVertex::loopIntegrals(Energy Mi, Energy Mj, Energy M, Energy m,
complex<InvEnergy2> & I, complex<InvEnergy2> & J,
complex<InvEnergy2> & K, complex<InvEnergy2> & I2) {
Energy2 m2(sqr(m)),M2(sqr(M)),Mi2(sqr(Mi)),Mj2(sqr(Mj));
double min2 = Mj2*UnitRemoval::InvE2;
double mout2 = Mi2*UnitRemoval::InvE2;
double mf2 = m2 *UnitRemoval::InvE2;
double ms2 = M2 *UnitRemoval::InvE2;
I = Looptools::C0i(Looptools::cc0,min2,mout2,0.,mf2,ms2,mf2)*UnitRemoval::InvE2;
J = Looptools::C0i(Looptools::cc0,min2,mout2,0.,ms2,mf2,ms2)*UnitRemoval::InvE2;
I2 =-Looptools::C0i(Looptools::cc1,min2,mout2,0.,mf2,ms2,mf2)*UnitRemoval::InvE2;
K = (1.+Complex(m2*I+M2*J-Mj2*I2))/(Mi2-Mj2);
if(_realIntegral) {
I = I .real();
J = J .real();
I2 = I2.real();
K = K .real();
}
}

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