Rivet analyses

title: ARGUS_1990_I298245

Electron and Muon spectra at the $\Upsilon(4S)$

Experiment: ARGUS (DORIS)

Inspire ID: 298245

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Lett.B 249 (1990) 359-365

Beams: * *

Beam energies: ANY

Run details: - Bottom mesons produced at the Upsilon(4S)

Electron and Muon spectra at the $\Upsilon(4S)$. The correct data were read from figure 3 in the paper.

Source code:ARGUS_1990_I298245.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief ARGUS lepton spectra class ARGUS_1990_I298245 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(ARGUS_1990_I298245);


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

/// Book histograms and initialise projections before the run
void init() {
  // projections
  declare(UnstableParticles(), "UFS");
  // histograms
  for (unsigned int ix = 0; ix < 2; ++ix) {
    book(_h[ix], 2, 1, 1 + ix);
  }
  book(_c, "TMP/nb");
}


void findDecayProducts(const Particle& parent, Particles& ee, Particles& mu) {
  for (const Particle& p : parent.children()) {
    if (p.abspid() == PID::EMINUS) {
      ee.push_back(p);
    }
    else if (p.abspid() == PID::MUON) {
      mu.push_back(p);
    }
    else if (!p.children().empty()) {
      findDecayProducts(p, ee, mu);
    }
  }
}

/// Perform the per-event analysis
void analyze(const Event& event) {
  const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
  for (const Particle& p : ufs.particles(Cuts::pid == 300553)) {
    // boost to rest frame
    LorentzTransform cms_boost;
    if (p.p3().mod() > 1 * MeV) {
      cms_boost = LorentzTransform::mkFrameTransformFromBeta(p.mom().betaVec());
    }
    // loop over decay products
    for (const Particle& p2 : p.children()) {
      if (p2.abspid() == 511 || p2.abspid() == 521) {
        _c->fill();
        // find decay products
        Particles leptons[2];
        findDecayProducts(p2, leptons[0], leptons[1]);
        for (unsigned int ix = 0; ix < 2; ++ix) {
          for (const Particle& lep : leptons[ix]) {
            FourMomentum pl = cms_boost.transform(lep.mom());
            _h[ix]->fill(pl.p3().mod());
          }
        }
      }
    }
  }
}


/// Normalise histograms etc., after the run
void finalize() {
  scale(_h, 1.0 / *_c);
}

/// @}


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

};

RIVET_DECLARE_PLUGIN(ARGUS_1990_I298245);

} ```