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Index: trunk/Readme.pdf
===================================================================
Cannot display: file marked as a binary type.
svn:mime-type = application/octet-stream
Index: trunk/src/gammaavm.cpp
===================================================================
--- trunk/src/gammaavm.cpp (revision 304)
+++ trunk/src/gammaavm.cpp (revision 305)
@@ -1,943 +1,949 @@
///////////////////////////////////////////////////////////////////////////
//
// Copyright 2010
//
// This file is part of starlight.
//
// starlight is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// starlight is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with starlight. If not, see <http://www.gnu.org/licenses/>.
//
///////////////////////////////////////////////////////////////////////////
//
// File and Version Information:
// $Rev:: $: revision of last commit
// $Author:: $: author of last commit
// $Date:: $: date of last commit
//
// Description:
// Added incoherent t2-> pt2 selection. Following pp selection scheme
//
//
///////////////////////////////////////////////////////////////////////////
#include <iostream>
#include <fstream>
#include <cassert>
#include <cmath>
#include "gammaavm.h"
#include "photonNucleusCrossSection.h"
#include "wideResonanceCrossSection.h"
#include "narrowResonanceCrossSection.h"
#include "incoherentVMCrossSection.h"
using namespace std;
//______________________________________________________________________________
Gammaavectormeson::Gammaavectormeson(const inputParameters& inputParametersInstance, randomGenerator* randy, beamBeamSystem& bbsystem):eventChannel(inputParametersInstance, randy, bbsystem), _phaseSpaceGen(0)
{
_VMNPT=inputParametersInstance.nmbPtBinsInterference();
_VMWmax=inputParametersInstance.maxW();
_VMWmin=inputParametersInstance.minW();
_VMYmax=inputParametersInstance.maxRapidity();
_VMYmin=-1.*_VMYmax;
_VMnumw=inputParametersInstance.nmbWBins();
_VMnumy=inputParametersInstance.nmbRapidityBins();
_VMgamma_em=inputParametersInstance.beamLorentzGamma();
_VMinterferencemode=inputParametersInstance.interferenceEnabled();
_VMbslope=0.;//Will define in wide/narrow constructor
_bslopeDef=inputParametersInstance.bslopeDefinition();
_bslopeVal=inputParametersInstance.bslopeValue();
_pEnergy= inputParametersInstance.protonEnergy();
_VMpidtest=inputParametersInstance.prodParticleType();
_VMptmax=inputParametersInstance.maxPtInterference();
_VMdpt=inputParametersInstance.ptBinWidthInterference();
_ProductionMode=inputParametersInstance.productionMode();
N0 = 0; N1 = 0; N2 = 0;
if (_VMpidtest == starlightConstants::FOURPRONG){
// create n-body phase-spage generator
_phaseSpaceGen = new nBodyPhaseSpaceGen(_randy);
}
}
//______________________________________________________________________________
Gammaavectormeson::~Gammaavectormeson()
{
if (_phaseSpaceGen)
delete _phaseSpaceGen;
}
//______________________________________________________________________________
void Gammaavectormeson::pickwy(double &W, double &Y)
{
double dW, dY, xw,xy,xtest,btest;
int IW,IY;
dW = (_VMWmax-_VMWmin)/double(_VMnumw);
dY = (_VMYmax-_VMYmin)/double(_VMnumy);
L201pwy:
xw = _randy->Rndom();
W = _VMWmin + xw*(_VMWmax-_VMWmin);
if (W < 2 * _ip->pionChargedMass())
goto L201pwy;
IW = int((W-_VMWmin)/dW);
xy = _randy->Rndom();
Y = _VMYmin + xy*(_VMYmax-_VMYmin);
IY = int((Y-_VMYmin)/dY);
xtest = _randy->Rndom();
if( xtest > _Farray[IW][IY] )
goto L201pwy;
N0++;
// Determine the target nucleus
// For pA this is given, for all other cases use the relative probabilities in _Farray1 and _Farray2
if( _bbs.beam1().A()==1 && _bbs.beam2().A() != 1){
if( _ProductionMode == 2 || _ProductionMode ==3){
_TargetBeam = 2;
} else {
_TargetBeam = 1;
}
} else if( _bbs.beam1().A() != 1 && _bbs.beam2().A()==1 ){
if( _ProductionMode == 2 || _ProductionMode ==3){
_TargetBeam = 1;
} else {
_TargetBeam = 2;
}
} else {
btest = _randy->Rndom();
if ( btest < _Farray1[IW][IY]/_Farray[IW][IY] ){
_TargetBeam = 2;
N2++;
} else {
_TargetBeam = 1;
N1++;
}
}
}
//______________________________________________________________________________
void Gammaavectormeson::twoBodyDecay(starlightConstants::particleTypeEnum &ipid,
double W,
double px0, double py0, double pz0,
double& px1, double& py1, double& pz1,
double& px2, double& py2, double& pz2,
int& iFbadevent)
{
// This routine decays a particle into two particles of mass mdec,
// taking spin into account
double pmag;
double phi,theta,Ecm;
double betax,betay,betaz;
double mdec=0.0;
double E1=0.0,E2=0.0;
// set the mass of the daughter particles
mdec=getDaughterMass(ipid);
// calculate the magnitude of the momenta
if(W < 2*mdec){
cout<<" ERROR: W="<<W<<endl;
iFbadevent = 1;
return;
}
pmag = sqrt(W*W/4. - mdec*mdec);
// pick an orientation, based on the spin
// phi has a flat distribution in 2*pi
phi = _randy->Rndom()*2.*starlightConstants::pi;
// find theta, the angle between one of the outgoing particles and
// the beamline, in the outgoing particles' rest frame
theta=getTheta(ipid);
// compute unboosted momenta
px1 = sin(theta)*cos(phi)*pmag;
py1 = sin(theta)*sin(phi)*pmag;
pz1 = cos(theta)*pmag;
px2 = -px1;
py2 = -py1;
pz2 = -pz1;
Ecm = sqrt(W*W+px0*px0+py0*py0+pz0*pz0);
E1 = sqrt(mdec*mdec+px1*px1+py1*py1+pz1*pz1);
E2 = sqrt(mdec*mdec+px2*px2+py2*py2+pz2*pz2);
betax = -(px0/Ecm);
betay = -(py0/Ecm);
betaz = -(pz0/Ecm);
transform (betax,betay,betaz,E1,px1,py1,pz1,iFbadevent);
transform (betax,betay,betaz,E2,px2,py2,pz2,iFbadevent);
if(iFbadevent == 1)
return;
}
//______________________________________________________________________________
// decays a particle into four particles with isotropic angular distribution
bool Gammaavectormeson::fourBodyDecay
(starlightConstants::particleTypeEnum& ipid,
const double , // E (unused)
const double W, // mass of produced particle
const double* p, // momentum of produced particle; expected to have size 3
lorentzVector* decayVecs, // array of Lorentz vectors of daughter particles; expected to have size 4
int& iFbadevent)
{
const double parentMass = W;
// set the mass of the daughter particles
const double daughterMass = getDaughterMass(ipid);
if (parentMass < 4 * daughterMass){
cout << " ERROR: W=" << parentMass << " GeV too small" << endl;
iFbadevent = 1;
return false;
}
// construct parent four-vector
const double parentEnergy = sqrt(p[0] * p[0] + p[1] * p[1] + p[2] * p[2]
+ parentMass * parentMass);
const lorentzVector parentVec(p[0], p[1], p[2], parentEnergy);
// setup n-body phase-space generator
assert(_phaseSpaceGen);
static bool firstCall = true;
if (firstCall) {
const double m[4] = {daughterMass, daughterMass, daughterMass, daughterMass};
_phaseSpaceGen->setDecay(4, m);
// estimate maximum phase-space weight
_phaseSpaceGen->setMaxWeight(1.01 * _phaseSpaceGen->estimateMaxWeight(_VMWmax));
firstCall = false;
}
// generate phase-space event
if (!_phaseSpaceGen->generateDecayAccepted(parentVec))
return false;
// set Lorentzvectors of decay daughters
for (unsigned int i = 0; i < 4; ++i)
decayVecs[i] = _phaseSpaceGen->daughter(i);
return true;
}
//______________________________________________________________________________
double Gammaavectormeson::getDaughterMass(starlightConstants::particleTypeEnum &ipid)
{
//This will return the daughter particles mass, and the final particles outputed id...
double mdec=0.;
switch(_VMpidtest){
case starlightConstants::RHO:
case starlightConstants::RHOZEUS:
case starlightConstants::FOURPRONG:
case starlightConstants::OMEGA:
mdec = _ip->pionChargedMass();
ipid = starlightConstants::PION;
break;
case starlightConstants::PHI:
mdec = _ip->kaonChargedMass();
ipid = starlightConstants::KAONCHARGE;
break;
case starlightConstants::JPSI:
mdec = _ip->mel();
ipid = starlightConstants::ELECTRON;
break;
case starlightConstants::JPSI_ee:
mdec = _ip->mel();
ipid = starlightConstants::ELECTRON;
break;
case starlightConstants::JPSI_mumu:
mdec = _ip->muonMass();
ipid = starlightConstants::MUON;
break;
case starlightConstants::JPSI_ppbar:
mdec = _ip->protonMass();
ipid = starlightConstants::PROTON;
break;
case starlightConstants::JPSI2S_ee:
mdec = _ip->mel();
ipid = starlightConstants::ELECTRON;
break;
case starlightConstants::JPSI2S_mumu:
mdec = _ip->muonMass();
ipid = starlightConstants::MUON;
break;
case starlightConstants::JPSI2S:
case starlightConstants::UPSILON:
case starlightConstants::UPSILON2S:
case starlightConstants::UPSILON3S:
mdec = _ip->muonMass();
ipid = starlightConstants::MUON;
break;
case starlightConstants::UPSILON_ee:
case starlightConstants::UPSILON2S_ee:
case starlightConstants::UPSILON3S_ee:
mdec = _ip->mel();
ipid = starlightConstants::ELECTRON;
break;
case starlightConstants::UPSILON_mumu:
case starlightConstants::UPSILON2S_mumu:
case starlightConstants::UPSILON3S_mumu:
mdec = _ip->muonMass();
ipid = starlightConstants::MUON;
break;
default: cout<<"No daughtermass defined, gammaavectormeson::getdaughtermass"<<endl;
}
return mdec;
}
//______________________________________________________________________________
double Gammaavectormeson::getTheta(starlightConstants::particleTypeEnum ipid)
{
//This depends on the decay angular distribution
//Valid for rho, phi, omega.
double theta=0.;
double xtest=0.;
double dndtheta=0.;
L200td:
theta = starlightConstants::pi*_randy->Rndom();
xtest = _randy->Rndom();
// Follow distribution for helicity +/-1
// Eq. 19 of J. Breitweg et al., Eur. Phys. J. C2, 247 (1998)
// SRK 11/14/2000
switch(ipid){
case starlightConstants::MUON:
case starlightConstants::ELECTRON:
//VM->ee/mumu
dndtheta = sin(theta)*(1.+(cos(theta)*cos(theta)));
break;
case starlightConstants::PROTON:
//Pick this angular distribution for J/psi --> ppbar
dndtheta = sin(theta)*(1.+(0.605*cos(theta)*cos(theta)));
break;
case starlightConstants::PION:
case starlightConstants::KAONCHARGE:
//rhos etc
dndtheta= sin(theta)*(1.-((cos(theta))*(cos(theta))));
break;
default: cout<<"No proper theta dependence defined, check gammaavectormeson::gettheta"<<endl;
}//end of switch
if(xtest > dndtheta)
goto L200td;
return theta;
}
//______________________________________________________________________________
double Gammaavectormeson::getWidth()
{
return _width;
}
//______________________________________________________________________________
double Gammaavectormeson::getMass()
{
return _mass;
}
//______________________________________________________________________________
double Gammaavectormeson::getSpin()
{
return 1.0; //VM spins are the same
}
//______________________________________________________________________________
void Gammaavectormeson::momenta(double W,double Y,double &E,double &px,double &py,double &pz,int &tcheck)
{
// This subroutine calculates momentum and energy of vector meson
// given W and Y, without interference. Subroutine vmpt handles
// production with interference
double Egam,Epom,tmin,pt1,pt2,phi1,phi2;
double px1,py1,px2,py2;
double pt,xt,xtest,ytest;
double t2;
//Find Egam,Epom in CM frame
if( _bbs.beam1().A()==1 && _bbs.beam2().A() != 1){
// This is pA
if( _ProductionMode == 2 || _ProductionMode ==3 ){
Egam = 0.5*W*exp(Y);
Epom = 0.5*W*exp(-Y);
}else{
Egam = 0.5*W*exp(-Y);
Epom = 0.5*W*exp(Y);
}
} else if( _bbs.beam2().A()==1 && _bbs.beam1().A() != 1 ){
// This is Ap
if( _ProductionMode == 2 || _ProductionMode == 3 ){
Egam = 0.5*W*exp(-Y);
Epom = 0.5*W*exp(Y);
}else{
Egam = 0.5*W*exp(Y);
Epom = 0.5*W*exp(-Y);
}
} else {
// This is pp or AA
if( _TargetBeam == 1 ){
Egam = 0.5*W*exp(-Y);
Epom = 0.5*W*exp(Y);
}
else {
Egam = 0.5*W*exp(Y);
Epom = 0.5*W*exp(-Y);
}
}
// } else if( _ProductionMode == 2 || _ProductionMode==3){
// Egam = 0.5*W*exp(-Y);
// Epom = 0.5*W*exp(Y);
// } else {
// Egam = 0.5*W*exp(Y);
// Epom = 0.5*W*exp(-Y);
// }
pt1 = pTgamma(Egam);
phi1 = 2.*starlightConstants::pi*_randy->Rndom();
if( (_bbs.beam1().A()==1 && _bbs.beam2().A()==1) ||
(_ProductionMode == 4) ) {
if( (_VMpidtest == starlightConstants::RHO) || (_VMpidtest == starlightConstants::RHOZEUS) || (_VMpidtest == starlightConstants::OMEGA)){
// Use dipole form factor for light VM
L555vm:
xtest = 2.0*_randy->Rndom();
double ttest = xtest*xtest;
ytest = _randy->Rndom();
double t0 = 1./2.23;
double yprob = xtest*_bbs.beam1().dipoleFormFactor(ttest,t0)*_bbs.beam1().dipoleFormFactor(ttest,t0);
if( ytest > yprob ) goto L555vm;
t2 = ttest;
pt2 = xtest;
}else{
//Use dsig/dt= exp(-_VMbslope*t) for heavy VM
double bslope_tdist = _VMbslope;
double Wgammap = 0.0;
switch(_bslopeDef){
case 0:
//This is the default, as before
bslope_tdist = _VMbslope;
break;
case 1:
//User defined value of bslope. BSLOPE_VALUE default is 4.0 if not set.
bslope_tdist = _bslopeVal;
if( N0 <= 1 )cout<<" ATTENTION: Using user defined value of bslope = "<<_bslopeVal<<endl;
break;
case 2:
//This is Wgammap dependence of b from H1 (Eur. Phys. J. C 46 (2006) 585)
Wgammap = sqrt(4.*Egam*_pEnergy);
bslope_tdist = 4.63 + 4.*0.164*log(Wgammap/90.0);
if( N0 <= 1 )cout<<" ATTENTION: Using energy dependent value of bslope!"<<endl;
break;
default:
cout<<" Undefined setting for BSLOPE_DEFINITION "<<endl;
}
xtest = _randy->Rndom();
// t2 = (-1./_VMbslope)*log(xtest);
t2 = (-1./bslope_tdist)*log(xtest);
pt2 = sqrt(1.*t2);
}
} else {
// >> Check tmin
tmin = ((Epom/_VMgamma_em)*(Epom/_VMgamma_em));
if(tmin > 0.5){
cout<<" WARNING: tmin= "<<tmin<<endl;
cout<< " Y = "<<Y<<" W = "<<W<<" Epom = "<<Epom<<" gamma = "<<_VMgamma_em<<endl;
cout<<" Will pick a new W,Y "<<endl;
tcheck = 1;
return;
}
L203vm:
xt = _randy->Rndom();
if( _bbs.beam1().A()==1 && _bbs.beam2().A() != 1){
if( _ProductionMode == 2 || _ProductionMode ==3){
- pt2 = 8.*xt*starlightConstants::hbarc/_bbs.beam2().nuclearRadius();
+
+ // Changed '8' to '32' 6 times below to extend the region of the p_T calculation up to 1 GeV.c SRK May 28, 2019
+// 'pt2' is the maximum vector meson momentum. For heavy nuclei, the '32'coefficient corresonds to about 1 GeV/c
+// The downside of the larger coefficient is that the sampling runs more slowly. This could be made into a parameter
+
+
+ pt2 = 32.*xt*starlightConstants::hbarc/_bbs.beam2().nuclearRadius();
}else{
- pt2 = 8.*xt*starlightConstants::hbarc/_bbs.beam1().nuclearRadius();
+ pt2 = 32.*xt*starlightConstants::hbarc/_bbs.beam1().nuclearRadius();
}
} else if( _bbs.beam2().A()==1 && _bbs.beam1().A() != 1 ){
if( _ProductionMode == 2 || _ProductionMode ==3){
- pt2 = 8.*xt*starlightConstants::hbarc/_bbs.beam1().nuclearRadius();
+ pt2 = 32.*xt*starlightConstants::hbarc/_bbs.beam1().nuclearRadius();
}else{
- pt2 = 8.*xt*starlightConstants::hbarc/_bbs.beam2().nuclearRadius();
+ pt2 = 32.*xt*starlightConstants::hbarc/_bbs.beam2().nuclearRadius();
}
} else if (_TargetBeam==1) {
- pt2 = 8.*xt*starlightConstants::hbarc/_bbs.beam1().nuclearRadius();
+ pt2 = 32.*xt*starlightConstants::hbarc/_bbs.beam1().nuclearRadius();
} else {
- pt2 = 8.*xt*starlightConstants::hbarc/_bbs.beam2().nuclearRadius();
+ pt2 = 32.*xt*starlightConstants::hbarc/_bbs.beam2().nuclearRadius();
}
xtest = _randy->Rndom();
t2 = tmin + pt2*pt2;
double comp=0.0;
if( _bbs.beam1().A()==1 && _bbs.beam2().A() != 1){
if( _ProductionMode == 2 || _ProductionMode ==3){
comp = _bbs.beam2().formFactor(t2)*_bbs.beam2().formFactor(t2)*pt2;
}else{
comp = _bbs.beam1().formFactor(t2)*_bbs.beam1().formFactor(t2)*pt2;
}
} else if( _bbs.beam2().A()==1 && _bbs.beam1().A() != 1 ){
if( _ProductionMode == 2 || _ProductionMode ==3){
comp = _bbs.beam1().formFactor(t2)*_bbs.beam1().formFactor(t2)*pt2;
}else{
comp = _bbs.beam2().formFactor(t2)*_bbs.beam2().formFactor(t2)*pt2;
}
} else if (_TargetBeam==1) {
comp = _bbs.beam1().formFactor(t2)*_bbs.beam1().formFactor(t2)*pt2;
} else {
comp = _bbs.beam2().formFactor(t2)*_bbs.beam2().formFactor(t2)*pt2;
}
if( xtest > comp ) goto L203vm;
}//else end from pp
phi2 = 2.*starlightConstants::pi*_randy->Rndom();
px1 = pt1*cos(phi1);
py1 = pt1*sin(phi1);
px2 = pt2*cos(phi2);
py2 = pt2*sin(phi2);
// Compute vector sum Pt = Pt1 + Pt2 to find pt for the vector meson
px = px1 + px2;
py = py1 + py2;
pt = sqrt( px*px + py*py );
E = sqrt(W*W+pt*pt)*cosh(Y);
pz = sqrt(W*W+pt*pt)*sinh(Y);
}
//______________________________________________________________________________
double Gammaavectormeson::pTgamma(double E)
{
// returns on random draw from pp(E) distribution
double ereds =0.,Cm=0.,Coef=0.,x=0.,pp=0.,test=0.,u=0.;
double singleformfactorCm=0.,singleformfactorpp1=0.,singleformfactorpp2=0.;
int satisfy =0;
ereds = (E/_VMgamma_em)*(E/_VMgamma_em);
//sqrt(3)*E/gamma_em is p_t where the distribution is a maximum
Cm = sqrt(3.)*E/_VMgamma_em;
// If E is very small, the drawing of a pT below is extre_ip->mel()y slow.
// ==> Set pT = sqrt(3.)*E/_VMgamma_em for very small E.
// Should have no observable consequences (JN, SRK 11-Sep-2014)
if( E < 0.0005 )return Cm;
//the amplitude of the p_t spectrum at the maximum
if( _bbs.beam1().A()==1 && _bbs.beam2().A() != 1){
if( _ProductionMode == 2 || _ProductionMode ==3 ){
singleformfactorCm=_bbs.beam1().formFactor(Cm*Cm+ereds);
}else{
singleformfactorCm=_bbs.beam2().formFactor(Cm*Cm+ereds);
}
} else if( _bbs.beam2().A()==1 && _bbs.beam1().A() != 1 ){
if( _ProductionMode == 2 || _ProductionMode ==3){
singleformfactorCm=_bbs.beam2().formFactor(Cm*Cm+ereds);
}else{
singleformfactorCm=_bbs.beam1().formFactor(Cm*Cm+ereds);
}
} else if (_TargetBeam == 1) {
singleformfactorCm=_bbs.beam2().formFactor(Cm*Cm+ereds);
} else {
singleformfactorCm=_bbs.beam1().formFactor(Cm*Cm+ereds);
}
Coef = 3.0*(singleformfactorCm*singleformfactorCm*Cm*Cm*Cm)/((2.*(starlightConstants::pi)*(ereds+Cm*Cm))*(2.*(starlightConstants::pi)*(ereds+Cm*Cm)));
//pick a test value pp, and find the amplitude there
x = _randy->Rndom();
if( _bbs.beam1().A()==1 && _bbs.beam2().A() != 1){
if( _ProductionMode == 2 || _ProductionMode ==3){
pp = x*5.*starlightConstants::hbarc/_bbs.beam1().nuclearRadius();
singleformfactorpp1=_bbs.beam1().formFactor(pp*pp+ereds);
}else{
pp = x*5.*starlightConstants::hbarc/_bbs.beam2().nuclearRadius();
singleformfactorpp1=_bbs.beam2().formFactor(pp*pp+ereds);
}
} else if( _bbs.beam2().A()==1 && _bbs.beam1().A() != 1 ){
if( _ProductionMode == 2 || _ProductionMode ==3){
pp = x*5.*starlightConstants::hbarc/_bbs.beam2().nuclearRadius();
singleformfactorpp1=_bbs.beam2().formFactor(pp*pp+ereds);
}else{
pp = x*5.*starlightConstants::hbarc/_bbs.beam1().nuclearRadius();
singleformfactorpp1=_bbs.beam1().formFactor(pp*pp+ereds);
}
} else if (_TargetBeam == 1) {
pp = x*5.*starlightConstants::hbarc/_bbs.beam2().nuclearRadius();
singleformfactorpp1=_bbs.beam1().formFactor(pp*pp+ereds);
} else {
pp = x*5.*starlightConstants::hbarc/_bbs.beam1().nuclearRadius();
singleformfactorpp1=_bbs.beam1().formFactor(pp*pp+ereds);
}
test = (singleformfactorpp1*singleformfactorpp1)*pp*pp*pp/((2.*starlightConstants::pi*(ereds+pp*pp))*(2.*starlightConstants::pi*(ereds+pp*pp)));
while(satisfy==0){
u = _randy->Rndom();
if(u*Coef <= test)
{
satisfy =1;
}
else{
x =_randy->Rndom();
if( _bbs.beam1().A()==1 && _bbs.beam2().A() != 1){
if( _ProductionMode == 2 || _ProductionMode ==3){
pp = x*5.*starlightConstants::hbarc/_bbs.beam1().nuclearRadius();
singleformfactorpp2=_bbs.beam1().formFactor(pp*pp+ereds);
}else{
pp = x*5.*starlightConstants::hbarc/_bbs.beam2().nuclearRadius();
singleformfactorpp2=_bbs.beam2().formFactor(pp*pp+ereds);
}
} else if( _bbs.beam2().A()==1 && _bbs.beam1().A() != 1 ){
if( _ProductionMode == 2 || _ProductionMode ==3){
pp = x*5.*starlightConstants::hbarc/_bbs.beam2().nuclearRadius();
singleformfactorpp2=_bbs.beam2().formFactor(pp*pp+ereds);
}else{
pp = x*5.*starlightConstants::hbarc/_bbs.beam1().nuclearRadius();
singleformfactorpp2=_bbs.beam1().formFactor(pp*pp+ereds);
}
} else if (_TargetBeam == 1) {
pp = x*5.*starlightConstants::hbarc/_bbs.beam2().nuclearRadius();
singleformfactorpp2=_bbs.beam1().formFactor(pp*pp+ereds);
} else {
pp = x*5.*starlightConstants::hbarc/_bbs.beam1().nuclearRadius();
singleformfactorpp2=_bbs.beam1().formFactor(pp*pp+ereds);
}
test = (singleformfactorpp2*singleformfactorpp2)*pp*pp*pp/(2.*starlightConstants::pi*(ereds+pp*pp)*2.*starlightConstants::pi*(ereds+pp*pp));
}
}
return pp;
}
//______________________________________________________________________________
void Gammaavectormeson::vmpt(double W,double Y,double &E,double &px,double &py, double &pz,
int&) // tcheck (unused)
{
// This function calculates momentum and energy of vector meson
// given W and Y, including interference.
// It gets the pt distribution from a lookup table.
double dY=0.,yleft=0.,yfract=0.,xpt=0.,pt1=0.,ptfract=0.,pt=0.,pt2=0.,theta=0.;
int IY=0,j=0;
dY = (_VMYmax-_VMYmin)/double(_VMnumy);
// Y is already fixed; choose a pt
// Follow the approach in pickwy
// in _fptarray(IY,pt) IY=1 corresponds to Y=0, IY=numy/2 corresponds to +y
// Changed, now works -y to +y.
IY=int((Y-_VMYmin)/dY);
if (IY > (_VMnumy)-1){
IY=(_VMnumy)-1;
}
yleft=(Y-_VMYmin)-(IY)*dY;
yfract=yleft*dY;
xpt=_randy->Rndom();
for(j=0;j<_VMNPT;j++){
if (xpt < _fptarray[IY][j]) goto L60;
}
if(j == _VMNPT) j = _VMNPT-1;
L60:
// now do linear interpolation - start with extremes
if (j == 0){
pt1=xpt/_fptarray[IY][j]*_VMdpt/2.;
goto L80;
}
if (j == _VMNPT-1){
pt1=(_VMptmax-_VMdpt/2.) + _VMdpt/2.*(xpt-_fptarray[IY][j])/(1.-_fptarray[IY][j]);
goto L80;
}
// we're in the middle
ptfract=(xpt-_fptarray[IY][j])/(_fptarray[IY][j+1]-_fptarray[IY][j]);
pt1=(j+1)*_VMdpt+ptfract*_VMdpt;
// at an extreme in y?
if (IY == (_VMnumy)-1){
pt=pt1;
goto L120;
}
L80:
// interpolate in y repeat for next fractional y bin
for(j=0;j<_VMNPT;j++){
if (xpt < _fptarray[IY+1][j]) goto L90;
}
if(j == _VMNPT) j = _VMNPT-1;
L90:
// now do linear interpolation - start with extremes
if (j == 0){
pt2=xpt/_fptarray[IY+1][j]*_VMdpt/2.;
goto L100;
}
if (j == _VMNPT-1){
pt2=(_VMptmax-_VMdpt/2.) + _VMdpt/2.*(xpt-_fptarray[IY+1][j])/(1.-_fptarray[IY+1][j]);
goto L100;
}
// we're in the middle
ptfract=(xpt-_fptarray[IY+1][j])/(_fptarray[IY+1][j+1]-_fptarray[IY+1][j]);
pt2=(j+1)*_VMdpt+ptfract*_VMdpt;
L100:
// now interpolate in y
pt=yfract*pt2+(1-yfract)*pt1;
L120:
// we have a pt
theta=2.*starlightConstants::pi*_randy->Rndom();
px=pt*cos(theta);
py=pt*sin(theta);
E = sqrt(W*W+pt*pt)*cosh(Y);
pz = sqrt(W*W+pt*pt)*sinh(Y);
// randomly choose to make pz negative 50% of the time
if(_randy->Rndom()>=0.5) pz = -pz;
}
//______________________________________________________________________________
starlightConstants::event Gammaavectormeson::produceEvent(int&)
{
//Note used; return default event
return starlightConstants::event();
}
//______________________________________________________________________________
upcEvent Gammaavectormeson::produceEvent()
{
// The new event type
upcEvent event;
int iFbadevent=0;
int tcheck=0;
starlightConstants::particleTypeEnum ipid = starlightConstants::UNKNOWN;
starlightConstants::particleTypeEnum vmpid = starlightConstants::UNKNOWN;
if (_VMpidtest == starlightConstants::FOURPRONG) {
double comenergy = 0;
double mom[3] = {0, 0, 0};
double E = 0;
lorentzVector decayVecs[4];
do {
double rapidity = 0;
pickwy(comenergy, rapidity);
if (_VMinterferencemode == 0)
momenta(comenergy, rapidity, E, mom[0], mom[1], mom[2], tcheck);
else if (_VMinterferencemode==1)
vmpt(comenergy, rapidity, E, mom[0], mom[1], mom[2], tcheck);
} while (!fourBodyDecay(ipid, E, comenergy, mom, decayVecs, iFbadevent));
if ((iFbadevent == 0) and (tcheck == 0))
for (unsigned int i = 0; i < 4; ++i) {
starlightParticle daughter(decayVecs[i].GetPx(),
decayVecs[i].GetPy(),
decayVecs[i].GetPz(),
starlightConstants::UNKNOWN, // energy
starlightConstants::UNKNOWN, // _mass
ipid,
(i < 2) ? -1 : +1);
event.addParticle(daughter);
}
} else {
double comenergy = 0.;
double rapidity = 0.;
double E = 0.;
double momx=0.,momy=0.,momz=0.;
double px2=0.,px1=0.,py2=0.,py1=0.,pz2=0.,pz1=0.;
bool accepted = false;
do{
pickwy(comenergy,rapidity);
if (_VMinterferencemode==0){
momenta(comenergy,rapidity,E,momx,momy,momz,tcheck);
} else if (_VMinterferencemode==1){
vmpt(comenergy,rapidity,E,momx,momy,momz,tcheck);
}
_nmbAttempts++;
vmpid = ipid;
twoBodyDecay(ipid,comenergy,momx,momy,momz,px1,py1,pz1,px2,py2,pz2,iFbadevent);
double pt1chk = sqrt(px1*px1+py1*py1);
double pt2chk = sqrt(px2*px2+py2*py2);
double eta1 = pseudoRapidity(px1, py1, pz1);
double eta2 = pseudoRapidity(px2, py2, pz2);
if(_ptCutEnabled && !_etaCutEnabled){
if(pt1chk > _ptCutMin && pt1chk < _ptCutMax && pt2chk > _ptCutMin && pt2chk < _ptCutMax){
accepted = true;
_nmbAccepted++;
}
}
else if(!_ptCutEnabled && _etaCutEnabled){
if(eta1 > _etaCutMin && eta1 < _etaCutMax && eta2 > _etaCutMin && eta2 < _etaCutMax){
accepted = true;
_nmbAccepted++;
}
}
else if(_ptCutEnabled && _etaCutEnabled){
if(pt1chk > _ptCutMin && pt1chk < _ptCutMax && pt2chk > _ptCutMin && pt2chk < _ptCutMax){
if(eta1 > _etaCutMin && eta1 < _etaCutMax && eta2 > _etaCutMin && eta2 < _etaCutMax){
accepted = true;
_nmbAccepted++;
}
}
}
else if(!_ptCutEnabled && !_etaCutEnabled)
_nmbAccepted++;
}while((_ptCutEnabled || _etaCutEnabled) && !accepted);
if (iFbadevent==0&&tcheck==0) {
int q1=0,q2=0;
int ipid1,ipid2=0;
double xtest = _randy->Rndom();
if (xtest<0.5)
{
q1=1;
q2=-1;
}
else {
q1=-1;
q2=1;
}
if ( ipid == 11 || ipid == 13 ){
ipid1 = -q1*ipid;
ipid2 = -q2*ipid;
} else {
ipid1 = q1*ipid;
ipid2 = q2*ipid;
}
double md = getDaughterMass(vmpid);
double Ed1 = sqrt(md*md+px1*px1+py1*py1+pz1*pz1);
starlightParticle particle1(px1, py1, pz1, Ed1, starlightConstants::UNKNOWN, ipid1, q1);
event.addParticle(particle1);
double Ed2 = sqrt(md*md+px2*px2+py2*py2+pz2*pz2);
starlightParticle particle2(px2, py2, pz2, Ed2, starlightConstants::UNKNOWN, ipid2, q2);
event.addParticle(particle2);
}
}
return event;
}
double Gammaavectormeson::pseudoRapidity(double px, double py, double pz)
{
double pT = sqrt(px*px + py*py);
double p = sqrt(pz*pz + pT*pT);
double eta = -99.9; if((p-pz) != 0){eta = 0.5*log((p+pz)/(p-pz));}
return eta;
}
//______________________________________________________________________________
Gammaanarrowvm::Gammaanarrowvm(const inputParameters& input, randomGenerator* randy, beamBeamSystem& bbsystem):Gammaavectormeson(input, randy, bbsystem)
{
cout<<"Reading in luminosity tables. Gammaanarrowvm()"<<endl;
read();
cout<<"Creating and calculating crosssection. Gammaanarrowvm()"<<endl;
narrowResonanceCrossSection sigma(input, bbsystem);
sigma.crossSectionCalculation(_bwnormsave);
setTotalChannelCrossSection(sigma.getPhotonNucleusSigma());
_VMbslope=sigma.slopeParameter();
}
//______________________________________________________________________________
Gammaanarrowvm::~Gammaanarrowvm()
{ }
//______________________________________________________________________________
Gammaaincoherentvm::Gammaaincoherentvm(const inputParameters& input, randomGenerator* randy, beamBeamSystem& bbsystem):Gammaavectormeson(input, randy, bbsystem)
{
cout<<"Reading in luminosity tables. Gammaainkoherentvm()"<<endl;
read();
cout<<"Creating and calculating crosssection. Gammaaincoherentvm()"<<endl;
incoherentVMCrossSection sigma(input, bbsystem);
sigma.crossSectionCalculation(_bwnormsave);
setTotalChannelCrossSection(sigma.getPhotonNucleusSigma());
_VMbslope=sigma.slopeParameter();
}
//______________________________________________________________________________
Gammaaincoherentvm::~Gammaaincoherentvm()
{ }
//______________________________________________________________________________
Gammaawidevm::Gammaawidevm(const inputParameters& input, randomGenerator* randy, beamBeamSystem& bbsystem):Gammaavectormeson(input, randy, bbsystem)
{
cout<<"Reading in luminosity tables. Gammaawidevm()"<<endl;
read();
cout<<"Creating and calculating crosssection. Gammaawidevm()"<<endl;
wideResonanceCrossSection sigma(input, bbsystem);
sigma.crossSectionCalculation(_bwnormsave);
setTotalChannelCrossSection(sigma.getPhotonNucleusSigma());
_VMbslope=sigma.slopeParameter();
}
//______________________________________________________________________________
Gammaawidevm::~Gammaawidevm()
{ }
Index: trunk/Readme.docx
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