Rivet analyses

title: BABAR_2006_I719111

Charm hadron spectra in $B^0$, $\bar{B}^0$ and $B^\pm$ decays

Experiment: BABAR (PEP-II)

Inspire ID: 719111

Status: VALIDATED

Authors: - Peter Richardson

References: - Phys.Rev. D75 (2007) 072002

Beams: * *

Beam energies: ANY

Run details: - Any process producing B0, Bbar0, B+, B-

Spectra of $D^0$, $\bar{D}^0$, $D^\pm$, $D_s^\pm$, $\Lambda^+_c$, $\bar\Lambda_c^-$ in $B^0$, $\bar{B}^0$ and $B^\pm$ decays measured by BaBar at the $\Upsilon(4S)$.

Source code:BABAR_2006_I719111.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief Charm meson spectra in bottom decays class BABAR_2006_I719111 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BABAR_2006_I719111);


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

/// Book histograms and initialise projections before the run
void init() {

  // Initialise and register projections
  declare(UnstableParticles(), "UFS");

  // Book histograms
  book(_h_Bm_D0, 1, 1, 1);
  book(_h_Bm_Dbar0, 1, 1, 2);
  book(_h_Bm_Dp, 2, 1, 1);
  book(_h_Bm_Dm, 2, 1, 2);
  book(_h_Bm_Dsp, 3, 1, 1);
  book(_h_Bm_Dsm, 3, 1, 2);
  book(_h_Bm_lam, 4, 1, 1);
  book(_h_Bm_lbar, 4, 1, 2);
  book(_h_Bbar0_D0, 5, 1, 1);
  book(_h_Bbar0_Dbar0, 5, 1, 2);
  book(_h_Bbar0_Dp, 6, 1, 1);
  book(_h_Bbar0_Dm, 6, 1, 2);
  book(_h_Bbar0_Dsp, 7, 1, 1);
  book(_h_Bbar0_Dsm, 7, 1, 2);
  book(_h_Bbar0_lam, 8, 1, 1);
  book(_h_Bbar0_lbar, 8, 1, 2);

  book(_c_Bm, "/TMP/Bm");
  book(_c_Bbar0, "/TMP/B0");
}

void findDecayProducts(Particle p,
                       Particles& D0,
                       Particles& Dbar0,
                       Particles& Dp,
                       Particles& Dm,
                       Particles& Dsp,
                       Particles& Dsm,
                       Particles& lam,
                       Particles& lbar) {
  for (const Particle& child : p.children()) {
    if (child.pid() == 421)
      D0.push_back(child);
    else if (child.pid() == -421)
      Dbar0.push_back(child);
    else if (child.pid() == 411)
      Dp.push_back(child);
    else if (child.pid() == -411)
      Dm.push_back(child);
    else if (child.pid() == 431)
      Dsp.push_back(child);
    else if (child.pid() == -431)
      Dsm.push_back(child);
    else if (child.pid() == 4122)
      lam.push_back(child);
    else if (child.pid() == -4122)
      lbar.push_back(child);
    else if (!child.children().empty())
      findDecayProducts(child, D0, Dbar0, Dp, Dm, Dsp, Dsm, lam, lbar);
  }
}

/// Perform the per-event analysis
void analyze(const Event& event) {
  const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
  for (const Particle& p : ufs.particles(Cuts::abspid == 511 || Cuts::abspid == 521)) {
    if (p.abspid() == 511)
      _c_Bbar0->fill();
    else if (p.abspid() == 521)
      _c_Bm->fill();
    Particles D0, Dbar0, Dp, Dm, Dsp, Dsm, lam, lbar;
    findDecayProducts(p, D0, Dbar0, Dp, Dm, Dsp, Dsm, lam, lbar);
    LorentzTransform boost = LorentzTransform::mkFrameTransformFromBeta(p.momentum().betaVec());
    if (p.pid() > 0) {
      swap(D0, Dbar0);
      swap(Dp, Dm);
      swap(Dsp, Dsm);
      swap(lam, lbar);
    }
    for (const Particle& child : D0) {
      double pChild = boost.transform(child.momentum()).p3().mod();
      if (p.abspid() == 521)
        _h_Bm_D0->fill(pChild);
      else
        _h_Bbar0_D0->fill(pChild);
    }
    for (const Particle& child : Dbar0) {
      double pChild = boost.transform(child.momentum()).p3().mod();
      if (p.abspid() == 521)
        _h_Bm_Dbar0->fill(pChild);
      else
        _h_Bbar0_Dbar0->fill(pChild);
    }
    for (const Particle& child : Dp) {
      double pChild = boost.transform(child.momentum()).p3().mod();
      if (p.abspid() == 521)
        _h_Bm_Dp->fill(pChild);
      else
        _h_Bbar0_Dp->fill(pChild);
    }
    for (const Particle& child : Dm) {
      double pChild = boost.transform(child.momentum()).p3().mod();
      if (p.abspid() == 521)
        _h_Bm_Dm->fill(pChild);
      else
        _h_Bbar0_Dm->fill(pChild);
    }
    for (const Particle& child : Dsp) {
      double pChild = boost.transform(child.momentum()).p3().mod();
      if (p.abspid() == 521)
        _h_Bm_Dsp->fill(pChild);
      else
        _h_Bbar0_Dsp->fill(pChild);
    }
    for (const Particle& child : Dsm) {
      double pChild = boost.transform(child.momentum()).p3().mod();
      if (p.abspid() == 521)
        _h_Bm_Dsm->fill(pChild);
      else
        _h_Bbar0_Dsm->fill(pChild);
    }
    for (const Particle& child : lam) {
      double pChild = boost.transform(child.momentum()).p3().mod();
      if (p.abspid() == 521)
        _h_Bm_lam->fill(pChild);
      else
        _h_Bbar0_lam->fill(pChild);
    }
    for (const Particle& child : lbar) {
      double pChild = boost.transform(child.momentum()).p3().mod();
      if (p.abspid() == 521)
        _h_Bm_lbar->fill(pChild);
      else
        _h_Bbar0_lbar->fill(pChild);
    }
  }
}


/// Normalise histograms etc., after the run
void finalize() {
  scale(_h_Bm_D0, 100. / _c_Bm->val());
  scale(_h_Bm_Dbar0, 100. / _c_Bm->val());
  scale(_h_Bm_Dp, 100. / _c_Bm->val());
  scale(_h_Bm_Dm, 100. / _c_Bm->val());
  scale(_h_Bm_Dsp, 100. / _c_Bm->val());
  scale(_h_Bm_Dsm, 100. / _c_Bm->val());
  scale(_h_Bm_lam, 100. / _c_Bm->val());
  scale(_h_Bm_lbar, 100. / _c_Bm->val());
  scale(_h_Bbar0_D0, 100. / _c_Bbar0->val());
  scale(_h_Bbar0_Dbar0, 100. / _c_Bbar0->val());
  scale(_h_Bbar0_Dp, 100. / _c_Bbar0->val());
  scale(_h_Bbar0_Dm, 100. / _c_Bbar0->val());
  scale(_h_Bbar0_Dsp, 100. / _c_Bbar0->val());
  scale(_h_Bbar0_Dsm, 100. / _c_Bbar0->val());
  scale(_h_Bbar0_lam, 100. / _c_Bbar0->val());
  scale(_h_Bbar0_lbar, 100. / _c_Bbar0->val());
}

/// @}


/// @name Histograms
/// @{
Histo1DPtr _h_Bm_D0, _h_Bm_Dbar0, _h_Bm_Dp, _h_Bm_Dm, _h_Bm_Dsp, _h_Bm_Dsm, _h_Bm_lam, _h_Bm_lbar,
    _h_Bbar0_D0;
Histo1DPtr _h_Bbar0_Dbar0, _h_Bbar0_Dp, _h_Bbar0_Dm, _h_Bbar0_Dsp, _h_Bbar0_Dsm, _h_Bbar0_lam,
    _h_Bbar0_lbar;

CounterPtr _c_Bm, _c_Bbar0;
/// @}

};

RIVET_DECLARE_PLUGIN(BABAR_2006_I719111);

} ```