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| // -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/Beam.hh"
#include "Rivet/Projections/UnstableParticles.hh"
namespace Rivet {
/// @brief Xi_c*0 spectrum
class CLEOII_1995_I397770 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(CLEOII_1995_I397770);
/// @name Analysis methods
///@{
/// Book histograms and initialise projections before the run
void init() {
// projections
declare(Beam(), "Beams");
declare(UnstableParticles(), "UFS");
// book histos
book(_h_x,2,1,1);
book(_r,3,1,1);
book(_c_xi,"TMP/c_xi");
}
// Check for explicit decay into pdgids
bool isDecay(const Particle& mother, vector<int> ids) {
if(mother.pid()<0) {
for(unsigned int ix=0;ix<ids.size();++ix)
ids[ix] *= -1;
}
// Trivial check to ignore any other decays but the one in question modulo photons
const Particles children = mother.children(Cuts::pid!=PID::PHOTON);
if (children.size()!=ids.size()) return false;
// Check for the explicit decay
return all(ids, [&](int i){return count(children, hasPID(i))==1;});
}
/// Perform the per-event analysis
void analyze(const Event& event) {
static const int idXi = 4314;
const ParticlePair& beams = apply<Beam>(event, "Beams").beams();
const double Emax = ( beams.first.p3().mod() + beams.second.p3().mod() ) / 2.0;
const double Pmax = sqrt(sqr(Emax)-sqr(2.645));
const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
for (const Particle& p : ufs.particles(Cuts::abspid==idXi)) {
double xp = p.momentum().p3().mod()/Pmax;
_h_x->fill(xp);
int sign = p.pid()/p.abspid();
if(isDecay(p,{sign*4232,-sign*211})) {
_r->fill(0.5);
}
}
unsigned int nxi = ufs.particles(Cuts::abspid==4232).size();
_c_xi->fill(nxi);
}
/// Normalise histograms etc., after the run
void finalize() {
normalize(_h_x);
scale(_r, 1./ *_c_xi);
}
///@}
/// @name Histograms
///@{
Histo1DPtr _h_x,_r;
CounterPtr _c_xi;
///@}
};
RIVET_DECLARE_PLUGIN(CLEOII_1995_I397770);
}
|