Rivet analyses

title: LHCB_2013_I1230344

Differential cross sections for $J/\psi$ and $\Upsilon(1,2,3S)$ production at 8 TeV

Experiment: LHCB (LHC)

Inspire ID: 1230344

Status: VALIDATED

Authors: - Peter Richardson

References: - JHEP 06 (2013) 064, 2013

Beams: p+ p+

Beam energies: (4000.0, 4000.0)GeV

Run details: - hadronic events with Jpsi and Upsilon production

Measurement of the double differential (in $p_\perp$ and $y$) cross section for $J/\psi$ and $\Upsilon(1,2,3S)$ production at 8 TeV by the LHCB collaboration.

Source code:LHCB_2013_I1230344.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief J/psi and Upslion production at 8 TeV class LHCB_2013_I1230344 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(LHCB_2013_I1230344);


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

/// Book histograms and initialise projections before the run
void init() {
  declare(UnstableParticles(), "UFS");
  for (unsigned iy = 0; iy < 2; ++iy) book(_h_Jpsi_y[iy], 2, 1, iy + 1);
  for (unsigned int iy = 0; iy < 3; ++iy) {
    book(_h_Jpsi[iy], {2.0, 2.5, 3.0, 3.5, 4.0, 4.5});
    for (unsigned int ix = 0; ix < 5; ++ix) {
      if (iy < 2)
        book(_h_Jpsi[iy]->bin(ix + 1), 3 + ix, 1, 1 + iy);
      else
        book(_h_Jpsi[iy]->bin(ix + 1), "TMP/Jpsi_" + toString(ix), refData(3 + ix, 1, 1));
    }
  }
  for (unsigned int iy = 0; iy < 3; ++iy) {
    book(_h_Ups_pT[iy], 9, 1, iy + 1);
    book(_h_Ups_y[iy], 10, 1, iy + 1);
    book(_h_Ups_pT_r[iy], "TMP/Ups_pT_" + toString(iy), refData(16, 1, 1));
    book(_h_Ups_y_r[iy], "TMP/Ups_y_" + toString(iy), refData(17, 1, 1));
    book(_h_Ups[iy], {2.0, 2.5, 3.0, 3.5, 4.0, 4.5});
    for (unsigned int ix = 0; ix < 5; ++ix) {
      book(_h_Ups[iy]->bin(ix + 1), 11 + ix, 1, 1 + iy);
    }
  }
}


/// Perform the per-event analysis
void analyze(const Event& event) {

  // Final state of unstable particles to get particle spectra
  const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
  // J/psi
  for (const Particle& p : ufs.particles(Cuts::pid == 443)) {
    // prompt/non-prompt
    bool nonPrompt = p.fromBottom();
    double absrap = p.absrap();
    double xp = p.perp();
    if (absrap < 2. || absrap > 4.5 || xp > 14.) continue;
    _h_Jpsi_y[nonPrompt]->fill(absrap);
    _h_Jpsi[nonPrompt]->fill(absrap, xp);
    _h_Jpsi[2]->fill(absrap, xp);
  }
  // upsilon
  for (const Particle& p :
       ufs.particles(Cuts::pid == 553 or Cuts::pid == 100553 or Cuts::pid == 200553)) {
    double absrap = p.absrap();
    double xp = p.perp();
    if (absrap < 2. || absrap > 4.5 || xp > 15.) continue;
    unsigned int iups = p.pid() / 100000;
    _h_Ups_pT[iups]->fill(xp);
    _h_Ups_y[iups]->fill(absrap);
    _h_Ups_pT_r[iups]->fill(xp);
    _h_Ups_y_r[iups]->fill(absrap);
    _h_Ups[iups]->fill(absrap, xp);
  }
}


/// Normalise histograms etc., after the run
void finalize() {
  // 1/2 due rapidity folding +/-
  double factor = 0.5 * crossSection() / nanobarn / sumOfWeights();
  // branching ratios for upsilon
  vector<double> br = {0.0248, 0.0193, 0.0218};
  for (unsigned int ix = 0; ix < 2; ++ix) {
    scale(_h_Jpsi_y[ix], factor);
  }
  for (unsigned int ix = 0; ix < 3; ++ix) {
    scale(_h_Ups_pT[ix], factor * br[ix]);
    scale(_h_Ups_y[ix], factor * br[ix]);
    scale(_h_Ups_pT_r[ix], factor * br[ix]);
    scale(_h_Ups_y_r[ix], factor * br[ix]);
    scale(_h_Ups[ix], factor * 1000. * br[ix]);
    divByGroupWidth(_h_Ups[ix]);
    scale(_h_Jpsi[ix], factor);
    divByGroupWidth(_h_Jpsi[ix]);
  }
  for (unsigned int ix = 0; ix < _h_Jpsi[0]->numBins(); ++ix) {
    Estimate1DPtr tmp;
    book(tmp, 3 + ix, 1, 3);
    divide(_h_Jpsi[1]->bin(ix + 1), _h_Jpsi[2]->bin(ix + 1), tmp);
    tmp->scale(100.);
  }
  for (unsigned int ix = 0; ix < 2; ++ix) {
    Estimate1DPtr tmp;
    book(tmp, 16, 1, 1 + ix);
    divide(_h_Ups_pT_r[ix + 1], _h_Ups_pT_r[0], tmp);
    book(tmp, 17, 1, 1 + ix);
    divide(_h_Ups_y_r[ix + 1], _h_Ups_y_r[0], tmp);
  }
}

/// @}


/// @name Histograms
/// @{
Histo1DPtr _h_Jpsi_y[2], _h_Ups_pT[3], _h_Ups_y[3], _h_Ups_pT_r[3], _h_Ups_y_r[3];
Histo1DGroupPtr _h_Jpsi[3], _h_Ups[3];
/// @}

};

RIVET_DECLARE_PLUGIN(LHCB_2013_I1230344);

} ```