Rivet analyses

title: BELLE_2022_I2512112

Hadronic mass distributions in $B\to D^{(*)}\pi(\pi)\ell\nu$ decays

Experiment: BELLE (KEKB)

Inspire ID: 2512112

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - arXiv: 2211.09833

Beams: * *

Beam energies: ANY

Run details: - Any process produding b0 and B+, originally Upsilon(4S) decay

Measurement of the mass of the hadronic system in $B\to D^{(*)}\pi(\pi)\ell\nu$ decays

Source code:BELLE_2022_I2512112.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/DecayedParticles.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief B -> D pi (pi) semileptonic class BELLE_2022_I2512112 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2022_I2512112);


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

/// Book histograms and initialise projections before the run
void init() {
  // Initialise and register projections
  UnstableParticles ufs = UnstableParticles(Cuts::abspid == 511 or Cuts::abspid == 521);
  declare(ufs, "UFS");
  DecayedParticles BB(ufs);
  BB.addStable(411);
  BB.addStable(-411);
  BB.addStable(421);
  BB.addStable(-421);
  BB.addStable(413);
  BB.addStable(-413);
  BB.addStable(423);
  BB.addStable(-423);
  BB.addStable(PID::PI0);
  declare(BB, "BB");
  // histograms
  for (unsigned int ix = 0; ix < 3; ++ix)
    for (unsigned int iy = 0; iy < 2; ++iy) book(_h[ix][iy], 1 + ix, 1, 1 + iy);
}


/// Perform the per-event analysis
void analyze(const Event& event) {
  static const map<PdgId, unsigned int> mode1[4] = {{{-421, 1}, {-211, 1}, {-11, 1}, {12, 1}},
                                                    {{421, 1}, {211, 1}, {11, 1}, {-12, 1}},
                                                    {{-421, 1}, {-211, 1}, {-13, 1}, {14, 1}},
                                                    {{421, 1}, {211, 1}, {13, 1}, {-14, 1}}};
  static const map<PdgId, unsigned int> mode2[4] = {{{-411, 1}, {211, 1}, {-11, 1}, {12, 1}},
                                                    {{411, 1}, {-211, 1}, {11, 1}, {-12, 1}},
                                                    {{-411, 1}, {211, 1}, {-13, 1}, {14, 1}},
                                                    {{411, 1}, {-211, 1}, {13, 1}, {-14, 1}}};
  static const map<PdgId, unsigned int> mode3[4] = {{{-423, 1}, {-211, 1}, {-11, 1}, {12, 1}},
                                                    {{423, 1}, {211, 1}, {11, 1}, {-12, 1}},
                                                    {{-423, 1}, {-211, 1}, {-13, 1}, {14, 1}},
                                                    {{423, 1}, {211, 1}, {13, 1}, {-14, 1}}};
  static const map<PdgId, unsigned int> mode4[4] = {{{-413, 1}, {211, 1}, {-11, 1}, {12, 1}},
                                                    {{413, 1}, {-211, 1}, {11, 1}, {-12, 1}},
                                                    {{-413, 1}, {211, 1}, {-13, 1}, {14, 1}},
                                                    {{413, 1}, {-211, 1}, {13, 1}, {-14, 1}}};
  static const map<PdgId, unsigned int> mode5[4] = {{{-411, 1}, {-211, 1}, {211, 1}, {-11, 1}, {12, 1}},
                                                    {{411, 1}, {-211, 1}, {211, 1}, {11, 1}, {-12, 1}},
                                                    {{-411, 1}, {-211, 1}, {211, 1}, {-13, 1}, {14, 1}},
                                                    {{411, 1}, {-211, 1}, {211, 1}, {13, 1}, {-14, 1}}};
  static const map<PdgId, unsigned int> mode6[4] = {{{-421, 1}, {-211, 1}, {211, 1}, {-11, 1}, {12, 1}},
                                                    {{421, 1}, {-211, 1}, {211, 1}, {11, 1}, {-12, 1}},
                                                    {{-421, 1}, {-211, 1}, {211, 1}, {-13, 1}, {14, 1}},
                                                    {{421, 1}, {-211, 1}, {211, 1}, {13, 1}, {-14, 1}}};
  // loop over B mesons
  DecayedParticles BB = apply<DecayedParticles>(event, "BB");
  // loop over particles
  for (unsigned int ix = 0; ix < BB.decaying().size(); ++ix) {
    for (unsigned int il = 0; il < 4; ++il) {
      int iD, iloc1, iloc2;
      if (BB.modeMatches(ix, 4, mode1[il])) {
        iloc1 = 0;
        iloc2 = 0;
        iD = -421;
      }
      else if (BB.modeMatches(ix, 4, mode2[il])) {
        iloc1 = 0;
        iloc2 = 1;
        iD = -411;
      }
      else if (BB.modeMatches(ix, 4, mode3[il])) {
        iloc1 = 1;
        iloc2 = 0;
        iD = -423;
      }
      else if (BB.modeMatches(ix, 4, mode4[il])) {
        iloc1 = 1;
        iloc2 = 1;
        iD = -413;
      }
      else if (BB.modeMatches(ix, 5, mode5[il])) {
        iloc1 = 2;
        iloc2 = 0;
        iD = -411;
      }
      else if (BB.modeMatches(ix, 5, mode6[il])) {
        iloc1 = 2;
        iloc2 = 1;
        iD = -421;
      }
      else
        continue;
      int sign = il % 2 == 0 ? 1 : -1;
      int ipi = -sign * 211;
      if (iloc2 == 1) ipi *= -1;
      const Particle& pi1 = BB.decayProducts()[ix].at(ipi)[0];
      const Particle& DD = BB.decayProducts()[ix].at(iD * sign)[0];
      FourMomentum pHad = pi1.momentum() + DD.momentum();
      if (iloc1 == 2) {
        const Particle& pi2 = BB.decayProducts()[ix].at(-ipi)[0];
        pHad += pi2.momentum();
      }
      double mass = pHad.mass();
      if (iloc1 == 1) mass -= DD.mass();
      _h[iloc1][iloc2]->fill(mass);
    }
  }
}


/// Normalise histograms etc., after the run
void finalize() {
  for (unsigned int ix = 0; ix < 3; ++ix)
    for (unsigned int iy = 0; iy < 2; ++iy) normalize(_h[ix][iy], 1., false);
}

/// @}


/// @name Histograms
/// @{
Histo1DPtr _h[3][2];
/// @}

};

RIVET_DECLARE_PLUGIN(BELLE_2022_I2512112);

} ```