1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/UnstableParticles.hh"
 4#include "Rivet/Projections/DecayedParticles.hh"
 5
 6namespace Rivet {
 7
 8
 9  /// @brief  D0 -> K- pi+ pi0
10  class CLEOII_2001_I537154 : public Analysis {
11  public:
12
13    /// Constructor
14    RIVET_DEFAULT_ANALYSIS_CTOR(CLEOII_2001_I537154);
15
16
17    /// @name Analysis methods
18    /// @{
19
20    /// Book histograms and initialise projections before the run
21    void init() {
22      // Initialise and register projections
23      UnstableParticles ufs = UnstableParticles(Cuts::abspid==421);
24      declare(ufs, "UFS");
25      DecayedParticles D0(ufs);
26      D0.addStable(PID::PI0);
27      D0.addStable(PID::K0S);
28      D0.addStable(PID::ETA);
29      D0.addStable(PID::ETAPRIME);
30      declare(D0, "D0");
31      // histograms
32      book(_h_Kpi0,1,1,1);
33      book(_h_Kpip,1,2,1);
34      book(_h_pipi,1,3,1);
35
36    }
37
38    /// Perform the per-event analysis
39    void analyze(const Event& event) {
40      static const double E0   = 22.1e-5  ;
41      static const double Ex   = -6.89e-5 ;
42      static const double Ey   = -27.1e-5 ; 
43      static const double Ex2  = 10.4e-5  ;
44      static const double Exy  = 38.2e-5  ;
45      static const double Ey2  = 12.4e-5  ;
46      static const double Ex3  = -3.00e-5;
47      static const double Ex2y = -7.97e-5;
48      static const double Exy2 = -12.8e-5;
49      static const double Ey3  = -0.53e-5;
50
51      static const map<PdgId,unsigned int> & mode   = { {-321,1},{ 211,1}, {111,1}};
52      static const map<PdgId,unsigned int> & modeCC = { { 321,1},{-211,1}, {111,1}};
53      DecayedParticles D0 = apply<DecayedParticles>(event, "D0");
54      // loop over particles
55      for(unsigned int ix=0;ix<D0.decaying().size();++ix) {
56	int sign = 1;
57	if (D0.decaying()[ix].pid()>0 && D0.modeMatches(ix,3,mode)) {
58	  sign=1;
59	}
60	else if  (D0.decaying()[ix].pid()<0 && D0.modeMatches(ix,3,modeCC)) {
61	  sign=-1;
62	}
63	else
64	  continue;
65	const Particles & pi0= D0.decayProducts()[ix].at(111);
66	const Particles & Km = D0.decayProducts()[ix].at(-sign*321);
67	const Particles & pip= D0.decayProducts()[ix].at( sign*211);
68	double mKpip = (Km [0].momentum() + pip[0].momentum()).mass2();
69	double mKpi0 = (Km [0].momentum() + pi0[0].momentum()).mass2();
70	double mpipi = (pi0[0].momentum() + pip[0].momentum()).mass2();
71	double eff = E0 + Ex*mKpip + Ey*mpipi +Ex2*sqr(mKpip)+Exy*mKpip*mpipi+Ey2*sqr(mpipi)
72	  +Ex3*pow(mKpip,3)+Ex2y*sqr(mKpip)*mpipi +Exy2*mKpip*sqr(mpipi)+Ey3*pow(mpipi,3);
73	_h_Kpi0->fill(mKpi0,eff);
74	_h_Kpip->fill(mKpip,eff);
75	_h_pipi->fill(mpipi,eff);
76      }
77    }
78
79    /// Normalise histograms etc., after the run
80    void finalize() {
81      normalize(_h_Kpi0);
82      normalize(_h_Kpip);
83      normalize(_h_pipi);
84    }
85
86    /// @}
87
88
89    /// @name Histograms
90    /// @{
91    Histo1DPtr _h_Kpi0,_h_Kpip,_h_pipi;
92    /// @}
93
94  };
95
96
97  RIVET_DECLARE_PLUGIN(CLEOII_2001_I537154);
98
99}