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113 | // -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"
namespace Rivet {
/// @brief Ds -> K+K-pi+pi+pi-
class BESIII_2022_I2051683 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BESIII_2022_I2051683);
/// @name Analysis methods
/// @{
/// Book histograms and initialise projections before the run
void init() {
// Initialise and register projections
declare(UnstableParticles(), "UFS");
for(unsigned int ix=0;ix<10;++ix)
book(_h[ix],1,1,1+ix);
}
void findDecayProducts(const Particle & mother, unsigned int & nstable,
Particles & pip , Particles & pim ,
Particles & Kp , Particles & Km ) {
for(const Particle & p : mother.children()) {
int id = p.pid();
if ( id == PID::KPLUS ) {
Kp.push_back(p);
++nstable;
}
else if (id == PID::KMINUS ) {
Km.push_back(p);
++nstable;
}
else if (id == PID::PIPLUS) {
pip.push_back(p);
++nstable;
}
else if (id == PID::PIMINUS) {
pim.push_back(p);
++nstable;
}
else if (id == PID::PI0 || id == PID::K0S||id == PID::K0L) {
++nstable;
}
else if ( !p.children().empty() ) {
findDecayProducts(p, nstable, pip, pim, Kp , Km);
}
else
++nstable;
}
}
/// Perform the per-event analysis
void analyze(const Event& event) {
for(const Particle& meson : apply<UnstableParticles>(event, "UFS").particles(Cuts::abspid== 431)) {
unsigned int nstable(0);
Particles pip, pim, Kp , Km;
findDecayProducts(meson, nstable, pip, pim, Kp , Km);
if (nstable!=5) continue;
if(meson.pid()<0) {
swap(pim,pip);
swap(Kp,Km);
}
if(pip.size()==2&&Km.size()==1&&Kp.size()==1&&pim.size()==1) {
double mpippim[2] = {(pim[0].momentum()+pip[0].momentum()).mass(),
(pim[0].momentum()+pip[1].momentum()).mass()};
if(mpippim[0]>mpippim[1]) {
swap( pip[0], pip[1]);
swap(mpippim[0],mpippim[1]);
}
double mKK = (Kp[0].momentum()+Km[0].momentum()).mass();
_h[0]->fill(mKK);
_h[1]->fill(mKK);
_h[2]->fill(mpippim[0]);
_h[3]->fill(mpippim[1]);
_h[4]->fill((Kp [0].momentum()+Km [0].momentum()+pim[0].momentum()).mass());
_h[5]->fill((Km [0].momentum()+pip[1].momentum()+pim[0].momentum()).mass());
_h[6]->fill((Kp [0].momentum()+pip[0].momentum()+pim[0].momentum()).mass());
_h[7]->fill((pim[0].momentum()+pip[0].momentum()+pip[1].momentum()).mass());
_h[8]->fill((Kp [0].momentum()+Km [0].momentum()+pip[1].momentum()+pim[0].momentum()).mass());
_h[9]->fill((Km [0].momentum()+pip[0].momentum()+pip[1].momentum()+pim[0].momentum()).mass());
}
}
}
/// Normalise histograms etc., after the run
void finalize() {
for(unsigned int ix=0;ix<10;++ix)
normalize(_h[ix],1.,false);
}
/// @}
/// @name Histograms
/// @{
Histo1DPtr _h[10];
/// @}
};
RIVET_DECLARE_PLUGIN(BESIII_2022_I2051683);
}
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