Rivet analyses
MC analysis of Dalitz plots in three-body D-meson decays
Experiment: ()
Status: VALIDATED
Authors: - Peter Richardson
References: none listed
Beams: * *
Beam energies: ANY
Run details: - Any process producing D mesons
Monte Carlo analysis of D0 → K̄0π+π−, D0 → K−π+π0, D+ → K−π+π+, D+ → K̄0π+π0, D+ → K+π−π+ and Ds+ → K+π−π+ including kinematic distributions and Dalitz plots.
Source
code:MC_DALITZ_D.cc
// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/DecayedParticles.hh"
#include "Rivet/Projections/UnstableParticles.hh"
namespace Rivet {
/// @brief Monte Carlo analysis of D-meson Dalitz decays
class MC_DALITZ_D : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(MC_DALITZ_D);
/// @name Analysis methods
/// @{
/// Book histograms and initialise projections before the run
void init() {
// Initialise and register projections
UnstableParticles ufs = UnstableParticles(Cuts::abspid==411 or
Cuts::abspid==421 or
Cuts::abspid==431);
declare(ufs, "UFS");
DecayedParticles DD(ufs);
DD.addStable(PID::PI0);
DD.addStable(PID::K0S);
declare(DD, "DD");
// Book histograms
book(_h_plus1, "h_plus1" ,200,0.,3. );
book(_h_minus1, "h_minus1" ,200,0.,3.2 );
book(_h_pipi1, "h_pipi1" ,200,0.,2. );
book(_h_minus2, "h_minus2" ,200,0.,3.2 );
book(_h_neutral2, "h_neutral2",200,0.,3.2 );
book(_h_pipi2, "h_pipi2" ,200,0.,2. );
book(_h_Kpilow3, "h_Kpilow3" ,200,0.,2. );
book(_h_Kpihigh3, "h_Kpihigh3" ,200,0.,3.2 );
book(_h_Kpiall3, "h_Kpiall3" ,200,0.,3. );
book(_h_pipi3, "h_pipi3" ,200,0.,2. );
book(_h_Kpip4, "h_Kpip4" ,200,0.,3.2 );
book(_h_pipi4, "h_pipi4" ,200,0.,2. );
book(_h_Kpi04, "h_Kpi04" ,200,0.,3.2);
book(_h_kppim5, "h_kppim5" ,200,0.,3. );
book(_h_kppip5, "h_kppip5" ,200,0.,3.1 );
book(_h_pippim5, "h_pippim5" ,200,0.,2. );
book(_h_kppim6, "h_kppim6" ,200,0.,3.5);
book(_h_kppip6, "h_kppip6" ,200,0.,3.5);
book(_h_pippim6, "h_pippim6" ,200,0.,2.5);
book(_h_kpkm1 ,"h_kpkm1",200,0.9,3.5);
book(_h_kppip7,"h_kppip7",200,0.3,3.5);
book(_h_kmpip1,"h_kmpip1",200,0.3,3.5);
book(_h_pipi5, "h_pipi5" ,200,0.,3.2 );
book(_h_pipi6, "h_pipi6" ,200,0.,3.2 );
book(_h_pipi7, "h_pipi7" ,200,0.,3.2 );
book(_dalitz1, "dalitz1" ,50,0.3,3.2,50,0.3,3.2);
book(_dalitz2, "dalitz2" ,50,0.3,3. ,50,0.3,3. );
book(_dalitz3, "dalitz3" ,50,0.3,2. ,50,0.07,2. );
book(_dalitz4, "dalitz4" ,50,0.3,3.1 ,50,0.07,2. );
book(_dalitz5, "dalitz5" ,50,0.,3. ,50,0.,2. );
book(_dalitz6, "dalitz6" ,50,0.3,3.5,50,0.07,2.5);
book(_dalitz7, "dalitz7" ,50,0.3,3.5,50,0.07,2.5);
book(_dalitz8, "dalitz8" ,50,0.,3.2,50,0.,3.2);
}
/// Perform the per-event analysis
void analyze(const Event& event) {
static const map<PdgId,unsigned int> & mode1 = { { 211,1}, {-211,1}, { 310,1} };
static const map<PdgId,unsigned int> & mode2 = { { 211,1}, {-321,1}, { 111,1} };
static const map<PdgId,unsigned int> & mode2CC = { {-211,1}, { 321,1}, { 111,1} };
static const map<PdgId,unsigned int> & mode3 = { { 211,1}, {-211,1}, { 111,1} };
static const map<PdgId,unsigned int> & mode4 = { { 211,2}, {-321,1} };
static const map<PdgId,unsigned int> & mode4CC = { {-211,2}, { 321,1} };
static const map<PdgId,unsigned int> & mode5 = { { 211,1}, { 111,1}, { 310,1} };
static const map<PdgId,unsigned int> & mode5CC = { {-211,1}, { 111,1}, { 310,1} };
static const map<PdgId,unsigned int> & mode6 = { { 211,1}, {-211,1}, { 321,1} };
static const map<PdgId,unsigned int> & mode6CC = { { 211,1}, {-211,1}, {-321,1} };
static const map<PdgId,unsigned int> & mode7 = { { 321,1}, {-321,1}, { 211,1} };
static const map<PdgId,unsigned int> & mode7CC = { { 321,1}, {-321,1}, {-211,1} };
DecayedParticles DD = apply<DecayedParticles>(event, "DD");
for (unsigned int ix=0;ix<DD.decaying().size();++ix) {
int sign = DD.decaying()[ix].pid()/DD.decaying()[ix].abspid();
if (DD.decaying()[ix].abspid()==421) {
if ( DD.modeMatches(ix,3,mode1 )) {
const Particle & K0 = DD.decayProducts()[ix].at( 310)[0];
const Particle & pip = DD.decayProducts()[ix].at( sign*211)[0];
const Particle & pim = DD.decayProducts()[ix].at(-sign*211)[0];
double mminus = (pim.momentum()+K0.momentum() ).mass2();
double mplus = (pip.momentum()+K0.momentum() ).mass2();
double mpipi = (pip.momentum()+pim.momentum()).mass2();
_h_plus1 ->fill(mplus);
_h_minus1 ->fill(mminus);
_h_pipi1 ->fill(mpipi);
_dalitz1 ->fill(mplus,mminus);
}
else if( ( DD.decaying()[ix].pid()>0 && DD.modeMatches(ix,3,mode2 )) ||
( DD.decaying()[ix].pid()<0 && DD.modeMatches(ix,3,mode2CC))) {
const Particle & pi0 = DD.decayProducts()[ix].at( 111)[0];
const Particle & pip = DD.decayProducts()[ix].at( sign*211)[0];
const Particle & Km = DD.decayProducts()[ix].at(-sign*321)[0];
double mneut = (Km.momentum()+pip.momentum()).mass2();
double mminus = (Km.momentum()+pi0.momentum()).mass2();
double mpipi = (pip.momentum()+pi0.momentum()).mass2();
_h_neutral2 ->fill(mneut);
_h_minus2 ->fill(mminus);
_h_pipi2 ->fill(mpipi);
_dalitz2->fill(mminus,mneut);
}
else if(DD.modeMatches(ix,3,mode3)) {
const Particle & pi0 = DD.decayProducts()[ix].at( 111)[0];
const Particle & pip = DD.decayProducts()[ix].at( sign*211)[0];
const Particle & pim = DD.decayProducts()[ix].at(-sign*211)[0];
double mneut = (pim.momentum()+pip.momentum()).mass2();
double mminus = (pim.momentum()+pi0.momentum()).mass2();
double mplus = (pip.momentum()+pi0.momentum()).mass2();
_h_pipi5 ->fill(mplus);
_h_pipi6 ->fill(mminus);
_h_pipi7 ->fill(mneut);
_dalitz8 ->fill(mplus,mminus);
}
}
else if(DD.decaying()[ix].abspid()==411) {
if(DD.modeMatches(ix,3,mode4 ) || DD.modeMatches(ix,3,mode4CC)) {
const Particles & pip = DD.decayProducts()[ix].at( sign*211);
const Particle & Km = DD.decayProducts()[ix].at(-sign*321)[0];
double mplus = (Km.momentum() +pip[0].momentum()).mass2();
double mminus = (Km.momentum() +pip[1].momentum()).mass2();
double mpipi = (pip[0].momentum()+pip[1].momentum()).mass2();
if(mplus<mminus) swap(mplus,mminus);
_h_Kpilow3 ->fill( mminus);
_h_Kpihigh3->fill( mplus);
_h_Kpiall3 ->fill( mminus);
_h_Kpiall3 ->fill( mplus);
_h_pipi3 ->fill( mpipi);
_dalitz3->fill(mminus,mpipi);
}
else if(DD.modeMatches(ix,3,mode5 ) || DD.modeMatches(ix,3,mode5CC)) {
const Particle & pi0 = DD.decayProducts()[ix].at( 111)[0];
const Particle & K0 = DD.decayProducts()[ix].at( 310)[0];
const Particle & pip = DD.decayProducts()[ix].at( sign*211)[0];
double mminus = (K0.momentum()+pip.momentum()).mass2();
double mplus = (K0.momentum()+pi0.momentum()).mass2();
double mpipi = (pip.momentum()+pi0.momentum()).mass2();
_h_Kpip4 ->fill( mminus);
_h_pipi4 ->fill( mpipi );
_h_Kpi04 ->fill( mplus );
_dalitz4->fill(mplus,mpipi);
}
else if(DD.modeMatches(ix,3,mode6 ) || DD.modeMatches(ix,3,mode6CC)) {
const Particle & pip = DD.decayProducts()[ix].at( sign*211)[0];
const Particle & pim = DD.decayProducts()[ix].at(-sign*211)[0];
const Particle & Kp = DD.decayProducts()[ix].at( sign*321)[0];
double mplus = (Kp .momentum()+pip.momentum()).mass2();
double mminus = (Kp .momentum()+pim.momentum()).mass2();
double mpipi = (pip.momentum()+pim.momentum()).mass2();
_h_kppim5 ->fill(mminus);
_h_kppip5 ->fill(mplus );
_h_pippim5->fill(mpipi );
_dalitz5->fill(mminus,mpipi);
}
}
else if(DD.decaying()[ix].abspid()==431) {
if(DD.modeMatches(ix,3,mode6 ) || DD.modeMatches(ix,3,mode6CC)) {
const Particle & pip = DD.decayProducts()[ix].at( sign*211)[0];
const Particle & pim = DD.decayProducts()[ix].at(-sign*211)[0];
const Particle & Kp = DD.decayProducts()[ix].at( sign*321)[0];
double mplus = (Kp .momentum()+pip.momentum()).mass2();
double mminus = (Kp .momentum()+pim.momentum()).mass2();
double mpipi = (pip.momentum()+pim.momentum()).mass2();
_h_kppim6 ->fill(mminus);
_h_kppip6 ->fill(mplus );
_h_pippim6->fill(mpipi );
_dalitz6->fill(mminus,mpipi);
}
else if(DD.modeMatches(ix,3,mode7 ) || DD.modeMatches(ix,3,mode7CC)) {
const Particle & Kp = DD.decayProducts()[ix].at( sign*321)[0];
const Particle & Km = DD.decayProducts()[ix].at(-sign*321)[0];
const Particle & pip = DD.decayProducts()[ix].at( sign*211)[0];
double mplus = (Kp.momentum()+pip.momentum()).mass2();
double mminus = (Km.momentum()+pip.momentum()).mass2();
double mKK = (Kp.momentum()+Km .momentum()).mass2();
_h_kpkm1->fill(mKK);
_h_kppip7->fill(mplus);
_h_kmpip1->fill(mminus);
_dalitz7->fill(mKK,mminus);
}
}
}
}
/// Normalise histograms etc., after the run
void finalize() {
normalize(_h_plus1);
normalize(_h_minus1);
normalize(_h_pipi1);
normalize(_dalitz1);
normalize(_h_minus2);
normalize(_h_pipi2);
normalize(_h_neutral2);
normalize(_dalitz2);
normalize(_h_Kpilow3);
normalize(_h_Kpihigh3);
normalize(_h_Kpiall3);
normalize(_h_pipi3);
normalize(_dalitz3);
normalize(_h_Kpip4);
normalize(_h_pipi4);
normalize(_h_Kpi04);
normalize(_dalitz4);
normalize(_h_kppim5);
normalize(_h_kppip5);
normalize(_h_pippim5);
normalize(_dalitz5);
normalize(_h_kppim6);
normalize(_h_kppip6);
normalize(_h_pippim6);
normalize(_dalitz6);
normalize(_h_kpkm1);
normalize(_h_kppip7);
normalize(_h_kmpip1);
normalize(_dalitz7);
normalize(_h_pipi5);
normalize(_h_pipi6);
normalize(_h_pipi7);
normalize(_dalitz8);
}
/// @}
/// @name Histograms
/// @{
// Histograms for D^0\to \bar{K}^0\pi^+\pi^-
//m^2_+
Histo1DPtr _h_plus1;
//m^2_+
Histo1DPtr _h_minus1;
//m^2_{\pi\pi}
Histo1DPtr _h_pipi1;
// Dalitz plot
Histo2DPtr _dalitz1;
// Histograms for D^0\to K^-\pi^+\pi^0
// Histogram for the K^-\pi^+ mass
Histo1DPtr _h_minus2;
// Histogram for the \pi^+\pi^0 mass
Histo1DPtr _h_pipi2;
// Histogram for the K^-\pi^0 mass
Histo1DPtr _h_neutral2;
// Dalitz plot
Histo2DPtr _dalitz2;
// Histograms for D^+\to K^-\pi^+\pi^+
// Histogram for K^-\pi^+ low
Histo1DPtr _h_Kpilow3;
// Histogram for K^-\pi^+ high
Histo1DPtr _h_Kpihigh3;
// Histogram for K^-\pi^+ all
Histo1DPtr _h_Kpiall3;
// Histogram for \pi^+\pi^-
Histo1DPtr _h_pipi3;
// Dalitz plot
Histo2DPtr _dalitz3;
// Histograms for D^+\to\bar{K}^0\pi^+\pi^0
// Histogram for the \bar{K}^0\pi^+ mass
Histo1DPtr _h_Kpip4;
// Histogram for the \pi^+\pi^0 mass
Histo1DPtr _h_pipi4;
// Histogram for the \bar{K}^0\pi^0 mass
Histo1DPtr _h_Kpi04;
// Dalitz plot
Histo2DPtr _dalitz4;
// Histograms for D^+\to K^+\pi^-\pi^+
// Histogram for K^+\pi^-
Histo1DPtr _h_kppim5;
// Histogram for K^+\pi^+
Histo1DPtr _h_kppip5;
// Histogram for \pi^+\pi^-
Histo1DPtr _h_pippim5;
// Dalitz plot
Histo2DPtr _dalitz5;
// Histograms for D_s^+\to K^+\pi^-\pi^+
// Histogram for K^+\pi^-
Histo1DPtr _h_kppim6;
// Histogram for K^+\pi^+
Histo1DPtr _h_kppip6;
// Histogram for \pi^+\pi^-
Histo1DPtr _h_pippim6;
// Dalitz plot
Histo2DPtr _dalitz6;
// Histograms for D_s^+\to K^+K^-\pi^+
// Histogram for K^+K^-
Histo1DPtr _h_kpkm1;
// Histogram for K^+\pi^+
Histo1DPtr _h_kppip7;
// Histogram for K^-\pi^+
Histo1DPtr _h_kmpip1;
// Dalitz plot
Histo2DPtr _dalitz7;
// Histograms for D0 -> pi+pi-pi0
// Histogram for pi+pi0
Histo1DPtr _h_pipi5;
// Histogram for pi-pi0
Histo1DPtr _h_pipi6;
// Histogram for pi+pi-
Histo1DPtr _h_pipi7;
// Dalitz plot
Histo2DPtr _dalitz8;
/// @}
};
RIVET_DECLARE_PLUGIN(MC_DALITZ_D);
}