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| // -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/FinalState.hh"
#include "Rivet/Projections/ChargedFinalState.hh"
#include "Rivet/Projections/FastJets.hh"
#include "Rivet/Projections/HadronicFinalState.hh"
#include "Rivet/Tools/BinnedHistogram.hh"
#include "fastjet/JetDefinition.hh"
namespace fastjet {
class P_scheme : public JetDefinition::Recombiner {
public:
std::string description() const {return "";}
void recombine(const PseudoJet & pa, const PseudoJet & pb,
PseudoJet & pab) const {
PseudoJet tmp = pa + pb;
double E = sqrt(tmp.px()*tmp.px() + tmp.py()*tmp.py() + tmp.pz()*tmp.pz());
pab.reset_momentum(tmp.px(), tmp.py(), tmp.pz(), E);
}
void preprocess(PseudoJet & p) const {
double E = sqrt(p.px()*p.px() + p.py()*p.py() + p.pz()*p.pz());
p.reset_momentum(p.px(), p.py(), p.pz(), E);
}
~P_scheme() { }
};
}
namespace Rivet {
class OPAL_2004_I631361 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(OPAL_2004_I631361);
/// @name Analysis methods
//@{
void init() {
// Get options from the new option system
_mode = 0;
if ( getOption("PROCESS") == "GG" ) _mode = 0;
if ( getOption("PROCESS") == "QQ" ) _mode = 1;
// projections we need for both cases
const FinalState fs;
declare(fs, "FS");
const ChargedFinalState cfs;
declare(cfs, "CFS");
// additional projections for q qbar
if(_mode==1) {
declare(HadronicFinalState(fs), "HFS");
declare(HadronicFinalState(cfs), "HCFS");
}
// book the histograms
if(_mode==0) {
int ih(0), iy(0);
if (inRange(0.5*sqrtS()/GeV, 5.0, 5.5)) {
ih = 1;
iy = 1;
} else if (inRange(0.5*sqrtS()/GeV, 5.5, 6.5)) {
ih = 1;
iy = 2;
} else if (inRange(0.5*sqrtS()/GeV, 6.5, 7.5)) {
ih = 1;
iy = 3;
} else if (inRange(0.5*sqrtS()/GeV, 7.5, 9.5)) {
ih = 2;
iy = 1;
} else if (inRange(0.5*sqrtS()/GeV, 9.5, 13.0)) {
ih = 2;
iy = 2;
} else if (inRange(0.5*sqrtS()/GeV, 13.0, 16.0)) {
ih = 3;
iy = 1;
} else if (inRange(0.5*sqrtS()/GeV, 16.0, 20.0)) {
ih = 3;
iy = 2;
}
if (!ih) MSG_WARNING("Option \"PROCESS=GG\" not compatible with this beam energy!");
assert(ih>0);
book(_h_chMult_gg, ih,1,iy);
if(ih==3) book(_h_chFragFunc_gg, 5,1,iy);
else _h_chFragFunc_gg = nullptr;
book(_sumW,"/TMP/sumW");
}
else {
Histo1DPtr dummy;
_h_chMult_qq.add( 5.0, 5.5, book(dummy, 1,1,1));
_h_chMult_qq.add( 5.5, 6.5, book(dummy, 1,1,2));
_h_chMult_qq.add( 6.5, 7.5, book(dummy, 1,1,3));
_h_chMult_qq.add( 7.5, 9.5, book(dummy, 2,1,1));
_h_chMult_qq.add( 9.5, 13.0, book(dummy, 2,1,2));
_h_chMult_qq.add(13.0, 16.0, book(dummy, 3,1,1));
_h_chMult_qq.add(16.0, 20.0, book(dummy, 3,1,2));
_h_chFragFunc_qq.add(13.0, 16.0, book(dummy, 5,1,1));
_h_chFragFunc_qq.add(16.0, 20.0, book(dummy, 5,1,2));
_sumWEbin.resize(7);
for (size_t i = 0; i < 7; ++i) {
book(_sumWEbin[i], "/TMP/sumWEbin" + to_string(i));
}
}
}
/// Perform the per-event analysis
void analyze(const Event& event) {
// gg mode
if(_mode==0) {
// find the initial gluons
Particles initial;
for (ConstGenParticlePtr p : HepMCUtils::particles(event.genEvent())) {
ConstGenVertexPtr pv = p->production_vertex();
const PdgId pid = p->pdg_id();
if(pid!=21) continue;
bool passed = false;
for (ConstGenParticlePtr pp : HepMCUtils::particles(pv, Relatives::PARENTS)) {
const PdgId ppid = abs(pp->pdg_id());
passed = (ppid == PID::ELECTRON || ppid == PID::HIGGS ||
ppid == PID::ZBOSON || ppid == PID::GAMMA);
if(passed) break;
}
if(passed) initial.push_back(Particle(*p));
}
if(initial.size()!=2) vetoEvent;
// use the direction for the event axis
Vector3 axis = initial[0].momentum().p3().unit();
// fill histograms
const Particles& chps = applyProjection<FinalState>(event, "CFS").particles();
unsigned int nMult[2] = {0,0};
// distribution
for (const Particle& p : chps) {
double xE = 2.*p.E()/sqrtS();
if(_h_chFragFunc_gg) _h_chFragFunc_gg->fill(xE);
if(p.momentum().p3().dot(axis)>0.)
++nMult[0];
else
++nMult[1];
}
// multiplicities in jet
_h_chMult_gg->fill(nMult[0]);
_h_chMult_gg->fill(nMult[1]);
_sumW->fill();
}
// qqbar mode
else {
// cut on the number of charged particles
const Particles& chParticles = applyProjection<FinalState>(event, "CFS").particles();
if(chParticles.size() < 5) vetoEvent;
// cluster the jets
const Particles& particles = applyProjection<FinalState>(event, "FS").particles();
fastjet::JetDefinition ee_kt_def(fastjet::ee_kt_algorithm, &p_scheme);
PseudoJets pParticles;
for (Particle p : particles) {
PseudoJet temp = p.pseudojet();
if(p.fromBottom()) {
temp.set_user_index(5);
}
pParticles.push_back(temp);
}
fastjet::ClusterSequence cluster(pParticles, ee_kt_def);
// rescale energys to just keep the directions of the jets
// and keep track of b tags
PseudoJets pJets = sorted_by_E(cluster.exclusive_jets_up_to(3));
if(pJets.size() < 3) vetoEvent;
array<Vector3, 3> dirs;
for(int i=0; i<3; i++) {
dirs[i] = Vector3(pJets[i].px(),pJets[i].py(),pJets[i].pz()).unit();
}
array<bool, 3> bTagged;
Jets jets;
for(int i=0; i<3; i++) {
double Ejet = sqrtS()*sin(angle(dirs[(i+1)%3],dirs[(i+2)%3])) /
(sin(angle(dirs[i],dirs[(i+1)%3])) + sin(angle(dirs[i],dirs[(i+2)%3])) + sin(angle(dirs[(i+1)%3],dirs[(i+2)%3])));
jets.push_back(FourMomentum(Ejet,Ejet*dirs[i].x(),Ejet*dirs[i].y(),Ejet*dirs[i].z()));
bTagged[i] = false;
for (PseudoJet particle : pJets[i].constituents()) {
if(particle.user_index() > 1 and !bTagged[i]) {
bTagged[i] = true;
}
}
}
int QUARK1 = 0, QUARK2 = 1, GLUON = 2;
if(jets[QUARK2].E() > jets[QUARK1].E()) swap(QUARK1, QUARK2);
if(jets[GLUON].E() > jets[QUARK1].E()) swap(QUARK1, GLUON);
if(!bTagged[QUARK2]) {
if(!bTagged[GLUON]) vetoEvent;
else swap(QUARK2, GLUON);
}
if(bTagged[GLUON]) vetoEvent;
// exclude collinear or soft jets
double k1 = jets[QUARK1].E()*min(angle(jets[QUARK1].momentum(),jets[QUARK2].momentum()),
angle(jets[QUARK1].momentum(),jets[GLUON].momentum()));
double k2 = jets[QUARK2].E()*min(angle(jets[QUARK2].momentum(),jets[QUARK1].momentum()),
angle(jets[QUARK2].momentum(),jets[GLUON].momentum()));
if(k1<8.0*GeV || k2<8.0*GeV) vetoEvent;
double sqg = (jets[QUARK1].momentum()+jets[GLUON].momentum()).mass2();
double sgq = (jets[QUARK2].momentum()+jets[GLUON].momentum()).mass2();
double s = (jets[QUARK1].momentum()+jets[QUARK2].momentum()+jets[GLUON].momentum()).mass2();
double Eg = 0.5*sqrt(sqg*sgq/s);
if(Eg < 5.0 || Eg > 46.) { vetoEvent; }
else if(Eg > 9.5) {
//requirements for experimental reconstructability raise as energy raises
if(!bTagged[QUARK1]) {
vetoEvent;
}
}
// all cuts applied, increment sum of weights
_sumWEbin[getEbin(Eg)]->fill();
// transform to frame with event in y-z and glue jet in z direction
Matrix3 glueTOz(jets[GLUON].momentum().vector3(), Vector3(0,0,1));
Vector3 transQuark = glueTOz*jets[QUARK2].momentum().vector3();
Matrix3 quarksTOyz(Vector3(transQuark.x(), transQuark.y(), 0), Vector3(0,1,0));
// work out transformation to symmetric frame
array<double, 3> x_cm;
array<double, 3> x_cm_y;
array<double, 3> x_cm_z;
array<double, 3> x_pr;
for(int i=0; i<3; i++) {
x_cm[i] = 2*jets[i].E()/sqrt(s);
Vector3 p_transf = quarksTOyz*glueTOz*jets[i].p3();
x_cm_y[i] = 2*p_transf.y()/sqrt(s);
x_cm_z[i] = 2*p_transf.z()/sqrt(s);
}
x_pr[GLUON] = sqrt(4*(1-x_cm[QUARK1])*(1-x_cm[QUARK2])/(3+x_cm[GLUON]));
x_pr[QUARK1] = x_pr[GLUON]/(1-x_cm[QUARK1]);
x_pr[QUARK2] = x_pr[GLUON]/(1-x_cm[QUARK2]);
double gamma = (x_pr[QUARK1] + x_pr[GLUON] + x_pr[QUARK2])/2;
double beta_z = x_pr[GLUON]/(gamma*x_cm[GLUON]) - 1;
double beta_y = (x_pr[QUARK2]/gamma - x_cm[QUARK2] - beta_z*x_cm_z[QUARK2])/x_cm_y[QUARK2];
LorentzTransform toSymmetric = LorentzTransform::mkObjTransformFromBeta(Vector3(0.,beta_y,beta_z)).
postMult(quarksTOyz*glueTOz);
FourMomentum transGlue = toSymmetric.transform(jets[GLUON].momentum());
double cutAngle = angle(toSymmetric.transform(jets[QUARK2].momentum()), transGlue)/2;
int nCh = 0;
for (const Particle& chP : chParticles ) {
FourMomentum pSymmFrame = toSymmetric.transform(FourMomentum(chP.p3().mod(), chP.px(), chP.py(), chP.pz()));
if(angle(pSymmFrame, transGlue) < cutAngle) {
_h_chFragFunc_qq.fill(Eg, pSymmFrame.E()*sin(cutAngle)/Eg);
nCh++;
}
}
_h_chMult_qq.fill(Eg, nCh);
}
}
/// Normalise histograms etc., after the run
void finalize() {
if(_mode==0) {
normalize(_h_chMult_gg);
if(_h_chFragFunc_gg) scale(_h_chFragFunc_gg, 0.5/(*_sumW));
}
else {
for (Histo1DPtr hist : _h_chMult_qq.histos()) {
normalize(hist);
}
for(int i=0; i<2; i++) {
if(!isZero(_sumWEbin[i+5]->val())) {
scale(_h_chFragFunc_qq.histos()[i], 1./(*_sumWEbin[i+5]));
}
}
}
}
//@}
private:
int getEbin(double E_glue) {
int ih = -1;
if (inRange(E_glue/GeV, 5.0, 5.5)) {
ih = 0;
} else if (inRange(E_glue/GeV, 5.5, 6.5)) {
ih = 1;
} else if (inRange(E_glue/GeV, 6.5, 7.5)) {
ih = 2;
} else if (inRange(E_glue/GeV, 7.5, 9.5)) {
ih = 3;
} else if (inRange(E_glue/GeV, 9.5, 13.0)) {
ih = 4;
} else if (inRange(E_glue/GeV, 13.0, 16.0)) {
ih = 5;
} else if (inRange(E_glue/GeV, 16.0, 20.0)) {
ih = 6;
}
assert(ih >= 0);
return ih;
}
class PScheme : public JetDefinition::Recombiner {
public:
std::string description() const {return "";}
void recombine(const PseudoJet & pa, const PseudoJet & pb, PseudoJet & pab) const {
PseudoJet tmp = pa + pb;
double E = sqrt(tmp.px()*tmp.px() + tmp.py()*tmp.py() + tmp.pz()*tmp.pz());
pab.reset_momentum(tmp.px(), tmp.py(), tmp.pz(), E);
}
void preprocess(PseudoJet & p) const {
double E = sqrt(p.px()*p.px() + p.py()*p.py() + p.pz()*p.pz());
p.reset_momentum(p.px(), p.py(), p.pz(), E);
}
~PScheme() { }
};
private:
// The mode
unsigned int _mode;
/// needed to normalize as normalised is integral = <average no particles>
vector<CounterPtr> _sumWEbin;
CounterPtr _sumW;
// p scheme jet definition
fastjet::P_scheme p_scheme;
/// @name Histograms
//@{
Histo1DPtr _h_chMult_gg;
Histo1DPtr _h_chFragFunc_gg;
BinnedHistogram _h_chMult_qq;
BinnedHistogram _h_chFragFunc_qq;
//@}
};
// The hook for the plugin system
RIVET_DECLARE_PLUGIN(OPAL_2004_I631361);
}
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