Rivet analyses

title: BELLE_2009_I820737

Mass distributions in $\bar{B}^0\to K^-\pi^+\psi(2S)$ and $B^+\to K^0_S\pi^+\psi(2S)$

Experiment: BELLE (KEKB)

Inspire ID: 820737

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev.D 80 (2009) 031104

Beams: * *

Beam energies: ANY

Run details: - Any process producing B+ and B0 mesons, originally Upsilon(4S) decays

Measurement of mass distributions in $\bar{B}^0\to K^-\pi^+\psi(2S)$ and $B^+\to K^0_S\pi^+\psi(2S)$ decays, only the average of the two modes is measured. The data were read from the plots in the paper and may not be corrected for efficiency/acceptance, however the backgrounds given in the paper have been subtracted.

Source code:BELLE_2009_I820737.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/DecayedParticles.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief B-> K pi psi(2S) class BELLE_2009_I820737 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2009_I820737);


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

/// Book histograms and initialise projections before the run
void init() {
  // Initialise and register projections
  UnstableParticles ufs = UnstableParticles(Cuts::abspid == 511 || Cuts::abspid == 521);
  declare(ufs, "UFS");
  DecayedParticles BB(ufs);
  BB.addStable(310);
  BB.addStable(100443);
  declare(BB, "BB");
  // histograms
  const vector<double> bins1 = {0, sqr(0.796), sqr(0.996), sqr(1.332), sqr(1.532), 3};
  const vector<double> bins2 = {0, 19.0, 20.5, 23};
  book(_h_piPsi, bins1, {"d01-x01-y01", "d01-x01-y02", "d01-x01-y03", "d01-x01-y04", "d01-x01-y05"});
  book(_h_Kpi, bins2, {"d02-x01-y01", "d02-x01-y02", "d02-x01-y03"});
  book(_h_veto, 3, 1, 1);
  book(_c, "TMP/nB");
}


/// Perform the per-event analysis
void analyze(const Event& event) {
  static const map<PdgId, unsigned int>& mode1 = {{321, 1}, {-211, 1}, {100443, 1}};
  static const map<PdgId, unsigned int>& mode1CC = {{-321, 1}, {211, 1}, {100443, 1}};
  static const map<PdgId, unsigned int>& mode2 = {{310, 1}, {-211, 1}, {100443, 1}};
  static const map<PdgId, unsigned int>& mode2CC = {{310, 1}, {211, 1}, {100443, 1}};
  DecayedParticles BB = apply<DecayedParticles>(event, "BB");
  // loop over particles
  for (unsigned int ix = 0; ix < BB.decaying().size(); ++ix) {
    int sign = 1, iK(0);
    if (BB.decaying()[ix].pid() > 0 && BB.modeMatches(ix, 3, mode1)) {
      sign = 1;
      iK = 321;
    }
    else if (BB.decaying()[ix].pid() < 0 && BB.modeMatches(ix, 3, mode1CC)) {
      sign = -1;
      iK = -321;
    }
    else if (BB.decaying()[ix].pid() < 0 && BB.modeMatches(ix, 3, mode2)) {
      sign = 1;
      iK = 310;
    }
    else if (BB.decaying()[ix].pid() > 0 && BB.modeMatches(ix, 3, mode2CC)) {
      sign = -1;
      iK = 310;
    }
    else {
      continue;
    }
    _c->fill();
    const Particle& Kp = BB.decayProducts()[ix].at(iK)[0];
    const Particle& pim = BB.decayProducts()[ix].at(-211 * sign)[0];
    const Particle& psi = BB.decayProducts()[ix].at(100443)[0];
    double m2Kpi = (Kp.momentum() + pim.momentum()).mass2();
    double m2Psipi = (psi.momentum() + pim.momentum()).mass2();
    _h_piPsi->fill(m2Kpi, m2Psipi);
    _h_Kpi->fill(m2Psipi, m2Kpi);
    if (m2Kpi < sqr(0.796) || (m2Kpi > sqr(0.996) && m2Kpi < sqr(1.332)) || m2Kpi > sqr(1.532))
      _h_veto->fill(m2Psipi);
  }
}


/// Normalise histograms etc., after the run
void finalize() {
  scale(_h_piPsi, 1. / *_c);
  scale(_h_Kpi, 1. / *_c);
  normalize(_h_veto, 1.0, false);
}

/// @}


/// @name Histograms
/// @{
Histo1DGroupPtr _h_piPsi, _h_Kpi;
CounterPtr _c;
Histo1DPtr _h_veto;
/// @}

};

RIVET_DECLARE_PLUGIN(BELLE_2009_I820737);

} ```