Rivet analyses

title: BELLE_2009_I816632

$D_s^{()-}K^+$ mass distribution in $B^+\to D_s^{()-}K^+\pi^+$ decays

Experiment: BELLE (KEKB)

Inspire ID: 816632

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev.D 80 (2009) 052005

Beams: * *

Beam energies: ANY

Run details: - Any process producing B+ mesons, originally Upsilon(4S) decays

Measurement of the $D_s^{()-}K^+$ mass distribution in $B^+\to D_s^{()-}K^+\pi^+$ decays. The data were read from the plots in the paper and may not be corrected for efficiency/acceptance, although the backgrounds given wre subtracted.

Source code:BELLE_2009_I816632.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/DecayedParticles.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief B+ -> D_s(*) K pi class BELLE_2009_I816632 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2009_I816632);


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

/// Book histograms and initialise projections before the run
void init() {
  // Initialise and register projections
  UnstableParticles ufs = UnstableParticles(Cuts::abspid == 521);
  declare(ufs, "UFS");
  DecayedParticles BP(ufs);
  BP.addStable(431);
  BP.addStable(-431);
  BP.addStable(433);
  BP.addStable(-433);
  declare(BP, "BP");
  // histograms
  for (unsigned int ix = 0; ix < 2; ++ix) {
    book(_h_mass[ix], 1, 1, 1 + ix);
  }
}


/// Perform the per-event analysis
void analyze(const Event& event) {
  static const map<PdgId, unsigned int>& mode1 = {{-431, 1}, {321, 1}, {211, 1}};
  static const map<PdgId, unsigned int>& mode1CC = {{431, 1}, {-321, 1}, {-211, 1}};
  static const map<PdgId, unsigned int>& mode2 = {{-433, 1}, {321, 1}, {211, 1}};
  static const map<PdgId, unsigned int>& mode2CC = {{433, 1}, {-321, 1}, {-211, 1}};
  DecayedParticles BP = apply<DecayedParticles>(event, "BP");
  // loop over particles
  for (unsigned int ix = 0; ix < BP.decaying().size(); ++ix) {
    int sign = 1, mode = 0;
    if (BP.modeMatches(ix, 3, mode1)) {
      mode = 0;
      sign = 1;
    }
    else if (BP.modeMatches(ix, 3, mode1CC)) {
      sign = -1;
      mode = 0;
    }
    else if (BP.modeMatches(ix, 3, mode2)) {
      mode = 1;
      sign = 1;
    }
    else if (BP.modeMatches(ix, 3, mode2CC)) {
      sign = -1;
      mode = 1;
    }
    else
      continue;
    const Particle& Ds = BP.decayProducts()[ix].at(-sign * (431 + 2 * mode))[0];
    const Particle& Kp = BP.decayProducts()[ix].at(sign * 321)[0];
    _h_mass[mode]->fill((Ds.momentum() + Kp.momentum()).mass());
  }
}


/// Normalise histograms etc., after the run
void finalize() {
  for (unsigned int ix = 0; ix < 2; ++ix) {
    normalize(_h_mass[ix], 1., false);
  }
}

/// @}


/// @name Histograms
/// @{
Histo1DPtr _h_mass[2];
/// @}

};

RIVET_DECLARE_PLUGIN(BELLE_2009_I816632);

} ```