// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/DecayedParticles.hh"
#include "Rivet/Projections/UnstableParticles.hh"
namespace Rivet {
/// @brief D+ -> K-pi+pi+
class FOCUS_2007_I750701 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(FOCUS_2007_I750701);
/// @name Analysis methods
/// @{
/// Book histograms and initialise projections before the run
void init() {
// Initialise and register projections
UnstableParticles ufs = UnstableParticles(Cuts::abspid== 411);
declare(ufs, "UFS");
DecayedParticles DP(ufs);
DP.addStable(PID::PI0);
declare(DP, "DP");
// histos
book(_h_low,1,1,1);
book(_h_high,1,1,2);
book(_dalitz, "dalitz",50,0.,3.1,50,0.3,3.1);
}
/// Perform the per-event analysis
void analyze(const Event& event) {
static const map<PdgId,unsigned int> & mode = { { 211,2}, {-321,1} };
static const map<PdgId,unsigned int> & modeCC = { {-211,2}, { 321,1} };
// Loop over D+ mesons
DecayedParticles DP = apply<DecayedParticles>(event, "DP");
for(unsigned int ix=0;ix<DP.decaying().size();++ix) {
int sign = 1;
if ( DP.modeMatches(ix,3,mode )) sign = 1;
else if( DP.modeMatches(ix,3,modeCC)) sign =-1;
else
continue;
const Particles & pip = DP.decayProducts()[ix].at( sign*211);
const Particle & Km = DP.decayProducts()[ix].at(-sign*321)[0];
double mplus = (Km.momentum() +pip[0].momentum()).mass2();
double mminus = (Km.momentum() +pip[1].momentum()).mass2();
if(mplus<mminus) swap(mplus,mminus);
_h_low ->fill(mminus);
_h_high->fill(mplus );
_dalitz->fill(mminus,mplus );
_dalitz->fill(mplus ,mminus);
}
}
/// Normalise histograms etc., after the run
void finalize() {
normalize(_h_low );
normalize(_h_high);
normalize(_dalitz);
}
/// @}
/// @name Histograms
/// @{
Histo1DPtr _h_high,_h_low;
Histo2DPtr _dalitz;
/// @}
};
RIVET_DECLARE_PLUGIN(FOCUS_2007_I750701);
}