Rivet analyses

Υ(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_⟂ and y) cross section for Υ(1, 2, 3S) production at 2.76 TeV by the LHCB collaboration.

Source code:`LHCB_2014_I1280929.cc`

// -*- 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);

}

Rivet analyses

Υ(1, 2, 3S) production at 2.76 TeV

Source code:LHCB_2014_I1280929.cc

Source code:`LHCB_2014_I1280929.cc`