Rivet analyses

title: LHCB_2014_I1280929

$\Upsilon(1,2,3S)$ production at 2.76 TeV

Experiment: LHCB (LHC)

Inspire ID: 1280929

Status: VALIDATED

Authors: - Peter Richardson

References: - Eur.Phys.J.C 74 (2014) 4, 2835

Beams: p+ p+

Beam energies: (1380.0, 1380.0)GeV

Run details: - hadronic events with Upsilon production

Measurement of the differential (in $p_\perp$ and $y$) cross section for $\Upsilon(1,2,3S)$ production at 2.76 TeV by the LHCB collaboration.

Source code:LHCB_2014_I1280929.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief Upsilon production at 2.76 TeV class LHCB_2014_I1280929 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(LHCB_2014_I1280929);


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

/// Book histograms and initialise projections before the run
void init() {
  declare(UnstableParticles(), "UFS");
  for (unsigned int iups = 0; iups < 3; ++iups) {
    book(_h_Ups_pT[iups], 3 + iups, 1, 1);
    book(_h_Ups_y[iups], 6 + iups, 1, 1);
    book(_h_Ups_y_r[iups], "TMP/UPS_y_" + toString(iups), refData(10, 1, 1));
  }
}


/// 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");
  // 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_y_r[iups]->fill(absrap);
  }
}


/// 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 < 3; ++ix) {
    scale(_h_Ups_pT[ix], factor * br[ix]);
    scale(_h_Ups_y[ix], factor * br[ix]);
    scale(_h_Ups_y_r[ix], factor * br[ix]);
  }
  for (unsigned int ix = 0; ix < 2; ++ix) {
    Estimate1DPtr tmp;
    book(tmp, 9, 1, 1 + ix);
    divide(_h_Ups_pT[ix + 1], _h_Ups_pT[0], tmp);
    book(tmp, 10, 1, 1 + ix);
    divide(_h_Ups_y_r[ix + 1], _h_Ups_y_r[0], tmp);
  }
}

/// @}


/// @name Histograms
/// @{
Histo1DPtr _h_Ups_pT[3], _h_Ups_y[3], _h_Ups_y_r[3];
/// @}

};

RIVET_DECLARE_PLUGIN(LHCB_2014_I1280929);

} ```