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| // -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"
#include "Rivet/Projections/ChargedFinalState.hh"
#include "Rivet/Projections/Thrust.hh"
#include "Rivet/Projections/Sphericity.hh"
namespace Rivet {
/// @brief Event shapes at Upsilon(1S)
class ARGUS_1986_I227324 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(ARGUS_1986_I227324);
/// @name Analysis methods
//@{
/// Book histograms and initialise projections before the run
void init() {
// projections
declare(UnstableParticles(), "UFS");
declare(ChargedFinalState(), "CFS");
const FinalState fs;
declare(Thrust(fs) ,"Thrust");
declare(Sphericity(fs),"Sphericity");
// histograms
if(isCompatibleWithSqrtS(9.98,1e-2)) {
book(_h_T_cont ,2, 1, 2);
book(_h_S_cont ,1, 1, 2);
}
book(_h_T_Ups ,2, 1, 1);
book(_h_S_Ups ,1, 1, 1);
}
/// Recursively walk the decay tree to find the stable decay products of @a p
void findDecayProducts(Particle mother, Particles& charged, Particles & neutral) {
for(const Particle & p: mother.children()) {
if(!p.children().empty())
findDecayProducts(p, charged, neutral);
else {
if(isCharged(p))
charged.push_back(p);
else
neutral.push_back(p);
}
}
}
/// Perform the per-event analysis
void analyze(const Event& event) {
// Find the Upsilons among the unstables
const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
Particles upsilons = ufs.particles(Cuts::pid==553 or Cuts::pid==100553);
if (upsilons.empty() && _h_T_cont) {
Particles charged = apply<ChargedFinalState>(event, "CFS").particles();
// at least 6 charged particles
if(charged.size()<6) vetoEvent;
// cut on high momentum particles
unsigned int nHigh(0);
for(const Particle & p : charged) {
if(p.momentum().p3().mod()>2.5) ++nHigh;
}
if(nHigh>1) vetoEvent;
MSG_DEBUG("No Upsilons found => continuum event");
Thrust thrust = apply<Thrust>(event, "Thrust");
_h_T_cont->fill(thrust.thrust());
Sphericity sphericity = apply<Sphericity>(event, "Sphericity");
_h_S_cont->fill(sphericity.sphericity());
}
else {
for (const Particle& ups : upsilons) {
LorentzTransform boost;
if (ups.p3().mod() > 1*MeV)
boost = LorentzTransform::mkFrameTransformFromBeta(ups.momentum().betaVec());
// Find the decay products we want
Particles charged,neutral;
// 6 charged particles
findDecayProducts(ups, charged, neutral);
if(charged.size()<6) continue;
// at most 1 |p|>2.5
vector<FourMomentum> mom;
mom.reserve(neutral.size()+charged.size());
unsigned int nHigh(0);
for(const Particle & p : charged) {
mom.push_back(boost.transform(p.momentum()));
if(mom.back().p3().mod()>2.5) ++nHigh;
}
if(nHigh>1) continue;
for(const Particle & p : neutral) {
mom.push_back(boost.transform(p.momentum()));
}
Thrust thrust;
thrust.calc(mom);
_h_T_Ups->fill(thrust.thrust());
Sphericity sphericity;
sphericity.calc(mom);
_h_S_Ups->fill(sphericity.sphericity());
}
}
}
/// Normalise histograms etc., after the run
void finalize() {
if(_h_T_cont) {
normalize(_h_T_cont);
normalize(_h_S_cont);
}
if(_h_T_Ups->numEntries()!=0.) {
normalize(_h_T_Ups);
normalize(_h_S_Ups);
}
}
//@}
/// @name Histograms
//@{
Histo1DPtr _h_T_Ups,_h_T_cont;
Histo1DPtr _h_S_Ups,_h_S_cont;
//@}
};
RIVET_DECLARE_PLUGIN(ARGUS_1986_I227324);
}
|