// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"
#include "Rivet/Projections/DecayedParticles.hh"
namespace Rivet {
/// @brief D+ -> pi+pi+pi-
class E791_2001_I530320 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(E791_2001_I530320);
/// @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);
DP.addStable(PID::K0S);
declare(DP,"DP");
// histos
book(_h_pi,1,1,1);
book(_dalitz, "dalitz",50,0.,3.1,50,0.0,3.1);
}
/// Perform the per-event analysis
void analyze(const Event& event) {
static const map<PdgId,unsigned int> & mode = { { 211,2},{-211,1}};
static const map<PdgId,unsigned int> & modeCC = { {-211,2},{ 211,1}};
DecayedParticles DP = apply<DecayedParticles>(event, "DP");
// loop over particles
for(unsigned int ix=0;ix<DP.decaying().size();++ix) {
int sign = 1;
if (DP.decaying()[ix].pid()>0 && DP.modeMatches(ix,3,mode)) {
sign=1;
}
else if (DP.decaying()[ix].pid()<0 && DP.modeMatches(ix,3,modeCC)) {
sign=-1;
}
else
continue;
const Particles & pip = DP.decayProducts()[ix].at( sign*211);
const Particle & pim = DP.decayProducts()[ix].at(-sign*211)[0];
double m1 = (pim.momentum()+pip[0].momentum()).mass2();
double m2 = (pim.momentum()+pip[1].momentum()).mass2();
_h_pi->fill(m1);
_h_pi->fill(m2);
_dalitz->fill(m1,m2);
_dalitz->fill(m2,m1);
}
}
/// Normalise histograms etc., after the run
void finalize() {
normalize(_h_pi);
normalize(_dalitz);
}
/// @}
/// @name Histograms
/// @{
Histo1DPtr _h_pi;
Histo2DPtr _dalitz;
/// @}
};
RIVET_DECLARE_PLUGIN(E791_2001_I530320);
}