Rivet analyses

title: CLEOIII_2006_I694170

Mass and angular distriubtions for $\Upsilon\to\pi^+\pi^-$, $K^+K^+$ and $p\bar{p}$

Experiment: CLEOIII (CESR)

Inspire ID: 694170

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev.D 73 (2006) 032001

Beams: e+ e-

Beam energies: (4.7, 4.7)GeV

Run details: - e+e- > hadrons at Upslion(1S)

Mass and angular distriubtions for $\Upsilon\to\pi^+\pi^-$, $K^+K^+$ and $p\bar{p}$. The background subtracted data were read from the plots in the paper

Source code:CLEOIII_2006_I694170.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/Beam.hh"

include "Rivet/Projections/DecayedParticles.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief Upsilon -> gamma pi+pi- K+K- ppbar class CLEOIII_2006_I694170 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(CLEOIII_2006_I694170);


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

/// Book histograms and initialise projections before the run
void init() {
  // Initialise and register projections
  UnstableParticles ufs = UnstableParticles(Cuts::abspid == 553);
  declare(ufs, "UFS");
  DecayedParticles UPS(ufs);
  declare(UPS, "UPS");
  declare(Beam(), "Beams");
  // histos
  for (unsigned int ix = 0; ix < 4; ++ix) {
    book(_h_mass[ix], 1 + ix, 1, 1);
  }
  for (unsigned int ix = 0; ix < 2; ++ix) {
    for (unsigned int iy = 0; iy < 2; ++iy) {
      book(_h_angle[ix][iy], 5 + ix, 1, 1 + iy);
    }
  }
}


/// Perform the per-event analysis
void analyze(const Event& event) {
  // get the axis, direction of incoming electron
  const ParticlePair& beams = apply<Beam>(event, "Beams").beams();
  Vector3 axis;
  if (beams.first.pid() > 0) {
    axis = beams.first.momentum().p3().unit();
  }
  else {
    axis = beams.second.momentum().p3().unit();
  }
  unsigned int iprod[3] = {211, 321, 2212};
  const map<PdgId, unsigned int> modes[3] = {{{211, 1}, {-211, 1}, {22, 1}},
                                             {{321, 1}, {-321, 1}, {22, 1}},
                                             {{2212, 1}, {-2212, 1}, {22, 1}}};
  DecayedParticles UPS = apply<DecayedParticles>(event, "UPS");
  if (UPS.decaying().size() != 1) vetoEvent;
  int imode = -1;
  for (unsigned int ix = 0; ix < 3; ++ix) {
    if (UPS.modeMatches(0, 3, modes[ix])) {
      imode = ix;
      break;
    }
  }
  if (imode < 0) vetoEvent;
  const Particle& Mp = UPS.decayProducts()[0].at(iprod[imode])[0];
  const Particle& Mm = UPS.decayProducts()[0].at(-iprod[imode])[0];
  FourMomentum pMM = Mp.momentum() + Mm.momentum();
  double mass = pMM.mass();
  if (imode == 0) {
    _h_mass[0]->fill(mass);
    _h_mass[1]->fill(mass);
  }
  else {
    _h_mass[1 + imode]->fill(mass);
  }
  if (imode == 2) return;
  bool hasf2[2] = {false, false};
  for (const Particle& p : UPS.decaying()[0].children()) {
    if (p.pid() == 225)
      hasf2[0] = true;
    else if (p.pid() == 335)
      hasf2[1] = true;
  }
  if ((imode == 0 && hasf2[0]) || (imode == 1 && hasf2[1])) {
    const Particle& gam = UPS.decayProducts()[0].at(22)[0];
    const double cTheta = axis.dot(gam.p3().unit());
    _h_angle[imode][1]->fill(abs(cTheta));
    // remaining angles
    LorentzTransform boost1 = LorentzTransform::mkFrameTransformFromBeta(
        UPS.decaying()[0].mom().betaVec());
    FourMomentum pGamma = boost1.transform(gam.mom());
    pMM = boost1.transform(pMM);
    Vector3 e1z = pGamma.p3().unit();
    LorentzTransform boost2 = LorentzTransform::mkFrameTransformFromBeta(pMM.betaVec());
    Vector3 axis2 = boost2.transform(boost1.transform(Mp.mom())).p3().unit();
    _h_angle[imode][0]->fill(abs(e1z.dot(axis2)));
  }
}


/// Normalise histograms etc., after the run
void finalize() {
  for (unsigned int ix = 0; ix < 4; ++ix) {
    normalize(_h_mass[ix], 1.0, false);
  }
  for (unsigned int ix = 0; ix < 2; ++ix) {
    for (unsigned int iy = 0; iy < 2; ++iy) {
      normalize(_h_angle[ix][iy], 1.0, false);
    }
  }
}

/// @}


/// @name Histograms
/// @{
Histo1DPtr _h_mass[4], _h_angle[2][2];
/// @}

};

RIVET_DECLARE_PLUGIN(CLEOIII_2006_I694170);

} ```