Rivet analyses

title: BELLE_2004_I658085

Mass distributions in $B\to D^* n\pi$ decays

Experiment: BELLE (KEKB)

Inspire ID: 658085

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev.D 70 (2004) 111103

Beams: * *

Beam energies: ANY

Run details: none listed

Measurement of mass distributions of the pions in the decays $B\to D^* n\pi$, where all the pions are charged. The data were read from, the plots in the papers but are corrected for efficiency.

Source code:BELLE_2004_I658085.cc

```c++ // -- C++ --

include "Rivet/Analysis.hh"

include "Rivet/Projections/DecayedParticles.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief B -> D* + pions class BELLE_2004_I658085 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2004_I658085);


/// @name Analysis methods
/// @{

/// Book histograms and initialise projections before the run
void init() {
  UnstableParticles ufs = UnstableParticles(Cuts::abspid == 511 || Cuts::abspid == 521);
  declare(ufs, "UFS");
  DecayedParticles BB(ufs);
  BB.addStable(PID::PI0);
  BB.addStable(413);
  BB.addStable(-413);
  BB.addStable(423);
  BB.addStable(-423);
  BB.addStable(PID::PI0);
  declare(BB, "BB");
  for (unsigned int ix = 0; ix < 6; ++ix) book(_h[ix], 1, 1, 1 + ix);
}


/// Perform the per-event analysis
void analyze(const Event& event) {
  // decay modes
  static const map<PdgId, unsigned int>& mode1 = {{-413, 1}, {211, 2}, {-211, 1}};
  static const map<PdgId, unsigned int>& mode1CC = {{413, 1}, {-211, 2}, {211, 1}};
  static const map<PdgId, unsigned int>& mode2 = {{-413, 1}, {211, 3}, {-211, 1}};
  static const map<PdgId, unsigned int>& mode2CC = {{413, 1}, {-211, 3}, {211, 1}};
  static const map<PdgId, unsigned int>& mode3 = {{-413, 1}, {211, 3}, {-211, 2}};
  static const map<PdgId, unsigned int>& mode3CC = {{413, 1}, {-211, 3}, {211, 2}};
  static const map<PdgId, unsigned int>& mode4 = {{-423, 1}, {211, 2}, {-211, 1}};
  static const map<PdgId, unsigned int>& mode4CC = {{423, 1}, {-211, 2}, {211, 1}};
  static const map<PdgId, unsigned int>& mode5 = {{-423, 1}, {211, 2}, {-211, 2}};
  static const map<PdgId, unsigned int>& mode5CC = {{423, 1}, {-211, 2}, {211, 2}};
  static const map<PdgId, unsigned int>& mode6 = {{-423, 1}, {211, 3}, {-211, 2}};
  static const map<PdgId, unsigned int>& mode6CC = {{423, 1}, {-211, 3}, {211, 2}};
  // loop over particles
  DecayedParticles BB = apply<DecayedParticles>(event, "BB");
  int imode = -1;
  for (unsigned int ix = 0; ix < BB.decaying().size(); ++ix) {
    int sign = BB.decaying()[ix].pid() / BB.decaying()[ix].abspid();
    if ((sign == 1 && BB.modeMatches(ix, 4, mode1)) || (sign == -1 && BB.modeMatches(ix, 4, mode1CC)))
      imode = 0;
    else if ((sign == 1 && BB.modeMatches(ix, 5, mode2))
             || (sign == -1 && BB.modeMatches(ix, 5, mode2CC)))
      imode = 1;
    else if ((sign == 1 && BB.modeMatches(ix, 6, mode3))
             || (sign == -1 && BB.modeMatches(ix, 6, mode3CC)))
      imode = 2;
    else if ((sign == 1 && BB.modeMatches(ix, 4, mode4))
             || (sign == -1 && BB.modeMatches(ix, 4, mode4CC)))
      imode = 3;
    else if ((sign == 1 && BB.modeMatches(ix, 5, mode5))
             || (sign == -1 && BB.modeMatches(ix, 5, mode5CC)))
      imode = 4;
    else if ((sign == 1 && BB.modeMatches(ix, 6, mode6))
             || (sign == -1 && BB.modeMatches(ix, 6, mode6CC)))
      imode = 5;
    else
      continue;
    FourMomentum ptotal;
    for (const Particle& p : BB.decayProducts()[ix].at(sign * 211)) {
      ptotal += p.momentum();
    }
    for (const Particle& p : BB.decayProducts()[ix].at(-sign * 211)) {
      ptotal += p.momentum();
    }
    _h[imode]->fill(ptotal.mass());
  }
}


/// Normalise histograms etc., after the run
void finalize() {
  for (unsigned int ix = 0; ix < 6; ++ix) normalize(_h[ix]);
}

/// @}


/// @name Histograms
/// @{
Histo1DPtr _h[6];
/// @}

};

RIVET_DECLARE_PLUGIN(BELLE_2004_I658085);

} ```