1// -*- C++ -*-
  2#include "Rivet/Analysis.hh"
  3#include "Rivet/Projections/UnstableParticles.hh"
  4
  5namespace Rivet {
  6
  7
  8  /// @brief B -> c l nu moments
  9  class CLEOII_2004_I647287 : public Analysis {
 10  public:
 11
 12    /// Constructor
 13    RIVET_DEFAULT_ANALYSIS_CTOR(CLEOII_2004_I647287);
 14
 15
 16    /// @name Analysis methods
 17    /// @{
 18
 19    /// Book histograms and initialise projections before the run
 20    void init() {
 21      // projections
 22      declare(UnstableParticles(Cuts::abspid==511 || Cuts::abspid==521),"UFS");
 23      // spin weighted average D and D* mass
 24      _mD2 = sqr(0.125*(1.86966+1.86484)+0.375*(2.00685+2.01026));
 25      // histograms
 26      for (unsigned int ix=0; ix<2; ++ix) {
 27        for (unsigned int iy=0; iy<4; ++iy) {
 28          if (iy%2==1) {
 29            book(_p[ix][iy],
 30                 "TMP/p_"+toString(ix)+"_"+toString(iy),
 31                 refData<YODA::BinnedEstimate<string>>(1,1+iy,1+ix));
 32          }
 33          else {
 34            book(_p[ix][iy],1,+1+iy,1+ix);
 35          }
 36        }
 37      }
 38      book(_p_dist,2,1,1);
 39    }
 40
 41    void findDecayProducts(const Particle& parent, Particles& em, Particles& ep,
 42                           Particles& nue, Particles& nueBar, bool & charm) {
 43      for (const Particle& p : parent.children()) {
 44        if (PID::isCharmHadron(p.pid())) {
 45          charm=true;
 46        }
 47        else if (p.pid() == PID::EMINUS || p.pid()==PID::MUON) {
 48          em.push_back(p);
 49        }
 50        else if (p.pid() == PID::EPLUS || p.pid()==PID::ANTIMUON) {
 51          ep.push_back(p);
 52        }
 53        else if (p.pid() == PID::NU_E  || p.pid()==PID::NU_MU) {
 54          nue.push_back(p);
 55        }
 56        else if (p.pid() == PID::NU_EBAR || p.pid()==PID::NU_MUBAR) {
 57          nueBar.push_back(p);
 58        }
 59        else if (PID::isBottomHadron(p.pid())) {
 60          findDecayProducts(p,em,ep,nue,nueBar,charm);
 61        }
 62        else if (!PID::isHadron(p.pid())) {
 63          findDecayProducts(p,em,ep,nue,nueBar,charm);
 64        }
 65      }
 66    }
 67
 68    /// Perform the per-event analysis
 69    void analyze(const Event& event) {
 70      if(_edges.empty()) _edges=_p_dist->xEdges();
 71      const double Ecut[2]={1.,1.5};
 72      // find and loop over Upslion(4S)
 73      for (const Particle& p : apply<UnstableParticles>(event, "UFS").particles()) {
 74        if (p.children().empty() ||
 75           (p.children().size()==1 && p.children()[1].abspid()==p.abspid())) {
 76          continue;
 77        }
 78        // find decay products
 79        bool charm = false;
 80        Particles em,ep,nue,nueBar;
 81        findDecayProducts(p,em,ep,nue,nueBar,charm);
 82        if (!charm) continue;
 83        FourMomentum pl,pnu;
 84        if (em.size()==1 && nueBar.size()==1 && em[0].pid()+1==-nueBar[0].pid()) {
 85          pl  = em[0].mom();
 86          pnu = nueBar[0].mom();
 87        }
 88        else if (ep.size()==1 && nue.size()==1 && nue[0].pid()==-ep[0].pid()+1) {
 89          pl  = ep[0].mom();
 90          pnu = nue[0].mom();
 91       	}
 92        else {
 93          continue;
 94        }
 95        // boost to rest frame
 96        LorentzTransform boost = LorentzTransform::mkFrameTransformFromBeta(p.mom().betaVec());
 97        double q2 = (pl+pnu).mass2();
 98        FourMomentum pX = boost.transform(p.mom()-pl-pnu);
 99        pl = boost.transform(pl);
100        double mX2  = pX.mass2();
101        for (unsigned int ix=0;ix<2;++ix) {
102          if (pl.E()>Ecut[ix]) {
103            _p[ix][0]->fill(_edges[5*ix],mX2-_mD2);
104            _p[ix][1]->fill(_edges[5*ix],sqr(mX2));
105            _p[ix][2]->fill(_edges[5*ix],q2);
106            _p[ix][3]->fill(_edges[5*ix],sqr(q2));
107          }
108        }
109        for(unsigned int ix=0;ix<6;++ix) {
110          if (1.+0.1*ix < pl.E())  _p_dist->fill(_edges[ix],mX2-_mD2);
111        }
112      }
113    }
114
115
116    /// Normalise histograms etc., after the run
117    void finalize() {
118      for (unsigned int ix=0; ix<2; ++ix) {
119        // compute <(mx2-<mx2>)^2> = <mx4>-<mx2>^2
120        BinnedEstimatePtr<string> tmp;
121        book(tmp,1,2,1+ix);
122        for (const auto& b0 : _p[ix][0]->bins()) {
123          const auto& b1 = _p[ix][1]->bin(b0.index());
124          const double val = b1.yMean()-sqr(b0.yMean()+_mD2);
125          const double err = val*sqrt(sqr(b1.relErrW())+4.*sqr(b0.yStdErr()/(b0.yMean()+_mD2)));
126          tmp->bin(b0.index()).set(val, err);
127        }
128        // compute <(q2-<q2>)^2> = <q4>-<q2>^2
129        book(tmp,1,4,1+ix);
130        for (const auto& b2 : _p[ix][2]->bins()) {
131          const auto& b3 = _p[ix][3]->bin(b2.index());
132          const double val = b3.yMean()-sqr(b2.yMean());
133          const double err = val*sqrt(sqr(b3.relErrW())+4.*sqr(b3.relErrW()));
134          tmp->bin(b2.index()).set(val, err);
135        }
136      }
137    }
138
139    /// @}
140
141
142    /// @name Histograms
143    /// @{
144    BinnedProfilePtr<string> _p[2][4], _p_dist;
145    vector<string> _edges;
146    double _mD2;
147    /// @}
148
149
150  };
151
152
153  RIVET_DECLARE_PLUGIN(CLEOII_2004_I647287);
154
155}