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| // -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/Beam.hh"
#include "Rivet/Projections/UnstableParticles.hh"
namespace Rivet {
/// @brief Excited Lambda_c spectra
class CLEOII_1994_I381696 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(CLEOII_1994_I381696);
/// @name Analysis methods
///@{
/// Book histograms and initialise projections before the run
void init() {
// projections
declare(Beam(), "Beams");
declare(UnstableParticles(), "UFS");
// book histos
book(_h_2595,5,1,1);
book(_h_2625,6,1,1);
book(_r_2595,4,1,1);
book(_r_2625,4,1,2);
book(_c_lam,"TMP/c_lam");
}
void findDecayProducts(const Particle& mother, unsigned int & npip,
unsigned int & npim, unsigned int & nlam) {
for(const Particle & p : mother.children()) {
if(p.abspid() == 4122) ++nlam;
else if(p.pid()== 211) ++npip;
else if(p.pid()== -211) ++npim;
else if(!p.children().empty())
findDecayProducts(p,npip,npim,nlam);
}
}
/// Perform the per-event analysis
void analyze(const Event& event) {
static const int id2595 = 14122;
static const int id2625 = 4124;
// Get beams and average beam momentum
const ParticlePair& beams = apply<Beam>(event, "Beams").beams();
const double Emax = ( beams.first.p3().mod() + beams.second.p3().mod() ) / 2.0;
const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
for (const Particle& p : ufs.particles(Cuts::abspid==id2595 or
Cuts::abspid==id2625)) {
unsigned int nlam(0),npip(0),npim(0);
findDecayProducts(p,npip,npim,nlam);
bool isDecay = npip==1 && npim==1 && nlam==1;
// spectrum
if(p.abspid()==id2595) {
double Pmax = sqrt(sqr(Emax)-sqr(2.595));
double xp = p.momentum().p3().mod()/Pmax;
_h_2595->fill(xp);
if(isDecay) _r_2595->fill(10.55);
}
else {
double Pmax = sqrt(sqr(Emax)-sqr(2.625));
double xp = p.momentum().p3().mod()/Pmax;
_h_2625->fill(xp);
if(isDecay) _r_2625->fill(10.55);
}
}
unsigned int nlam = ufs.particles(Cuts::abspid==4122).size();
_c_lam->fill(nlam);
}
/// Normalise histograms etc., after the run
void finalize() {
normalize(_h_2595);
normalize(_h_2625);
scale(_r_2595, 0.06/ *_c_lam);
scale(_r_2625, 0.06/ *_c_lam);
}
///@}
/// @name Histograms
///@{
Histo1DPtr _h_2595,_h_2625;
Histo1DPtr _r_2595,_r_2625;
CounterPtr _c_lam;
///@}
};
RIVET_DECLARE_PLUGIN(CLEOII_1994_I381696);
}
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