1// -*- C++ -*-
  2#include "Rivet/Analysis.hh"
  3#include "Rivet/Projections/UnstableParticles.hh"
  4
  5namespace Rivet {
  6
  7
  8  /// @brief Add a short analysis description here
  9  class ALEPH_2014_I1267648 : public Analysis {
 10  public:
 11
 12    /// Constructor
 13    RIVET_DEFAULT_ANALYSIS_CTOR(ALEPH_2014_I1267648);
 14
 15
 16    /// @name Analysis methods
 17    /// @{
 18
 19    /// Book histograms and initialise projections before the run
 20    void init() {
 21
 22      // Initialise and register projections
 23      declare(UnstableParticles(), "UFS");
 24
 25      // Book histograms
 26      for(unsigned int ix=0;ix<5;++ix)
 27        book(_h[ix], "TMP/h_"+toString(ix+1),refData(1+ix,1,1));
 28      book(_c,"TMP/ntau");
 29    }
 30
 31
 32    void findDecayProducts(const Particle &mother, const int isign, unsigned int &nstable, unsigned int &npip,
 33                           unsigned int &npim, unsigned int &npi0, FourMomentum &ptot) {
 34      for (const Particle &p : mother.children()) {
 35        int id = p.pid();
 36        if (id == PID::KPLUS || id == PID::KMINUS) {
 37          ++nstable;
 38          ptot += p.momentum();
 39        }
 40        else if (id*isign == PID::PIPLUS) {
 41          ++npip;
 42          ++nstable;
 43          ptot += p.momentum();
 44        }
 45        else if (id*isign == PID::PIMINUS) {
 46          ++npim;
 47          ++nstable;
 48          ptot += p.momentum();
 49        }
 50        else if (id == PID::PI0) {
 51          ++nstable;
 52          ++npi0;
 53          ptot += p.momentum();
 54        }
 55        else if (id == PID::PHOTON)  continue;
 56        else if (!p.children().empty())  findDecayProducts(p, isign, nstable, npip, npim, npi0, ptot);
 57        else  ++nstable;
 58      }
 59    }
 60
 61
 62    /// Perform the per-event analysis
 63    void analyze(const Event& event) {
 64
 65      // Loop over taus
 66      for (const Particle& tau : apply<UnstableParticles>(event, "UFS").particles(Cuts::abspid==PID::TAU)) {
 67        _c->fill();
 68        FourMomentum ptot;
 69        unsigned int nstable(0), npip(0), npim(0), npi0(0);
 70        findDecayProducts(tau,tau.pid()/tau.abspid(),nstable,npip,npim,npi0,ptot);
 71        // tau -> pi pi0 nu_tau (both charges)
 72        if (npim==1 && npi0==1 && nstable==3)  _h[0]->fill(ptot.mass2());
 73        // tau -> pi pi0 pi0 nu_tau (both charges)
 74        else if (npim==1 && npi0==2 && nstable==4)  _h[1]->fill(ptot.mass2());
 75        //    tau -> pi pi0 pi0 pi0         (3,1,1)
 76        else if (npim==1 && npi0==3 && nstable==5)  _h[2]->fill(ptot.mass2());
 77        //    tau -> 3 charged pions        (4,1,1)
 78        else if (npim==2 && npip==1 && nstable==4)  _h[3]->fill(ptot.mass2());
 79        //    tau -> 3 charged pions + pi0  (5,1,1)
 80        else if (npim==2 && npip==1 && npi0==1 && nstable==5)  _h[4]->fill(ptot.mass2());
 81      }
 82    }
 83
 84
 85    /// Normalise histograms etc., after the run
 86    void finalize() {
 87      for(unsigned int ix=0;ix<5;++ix) {
 88        scale(_h[ix] ,100./ *_c);
 89        Estimate1DPtr tmp;
 90        book(tmp,1+ix,1,1);
 91        barchart(_h[ix],tmp);
 92      }
 93    }
 94
 95    /// @}
 96
 97
 98  private:
 99
100
101    /// @name Histograms
102    /// @{
103    Histo1DPtr _h[5];
104    CounterPtr _c;
105    /// @}
106  };
107
108
109  RIVET_DECLARE_PLUGIN(ALEPH_2014_I1267648);
110
111}