Rivet analyses

Measurements of the Υ(1S), Υ(2S), and Υ(3S) differential cross sections in pp collisions at $\sqrt{s}=7$ TeV

Experiment: CMS (LHC)

Inspire ID: 1342266

Status: VALIDATED

Authors: - Daniel Clarke - Peter Richardson

References: - Phys.Lett.B 749 (2015) 14-34 - arXiv: 1501.07750 - Expt page: CMS-BPH-12-006

Beams: p+ p+

Beam energies: (3500.0, 3500.0)GeV

Run details: - Upsilon production at LHC energies

Measurement of the transverse momentum distribtions for Υ(1S), Υ(2S), and Υ(3S) production in three rapidity intervals. The production ratios are also measured.

Source code:CMS_2015_I1342266.cc

// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

  class CMS_2015_I1342266 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(CMS_2015_I1342266);

    /// Book histograms and initialise projections before the run
    void init() {
      declare(UnstableParticles(), "UFS");
      for (unsigned int ix = 0; ix < 3; ++ix) {
        book(_h_dy_pT[ix], {0.0, 0.6, 1.2});
        for (unsigned int iy = 1; iy < 3; ++iy) {
          book(_h_dy_pT[ix]->bin(iy), iy, 1, 1 + ix);
        }
        book(_h_pT[ix], 3, 1, 1 + ix);
      }
    }

    /// 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");

      for (const Particle& p :
           ufs.particles(Cuts::pid == 553 || Cuts::pid == 100553 || Cuts::pid == 200553)) {
        const double absrap = p.absrap();
        const double xp = p.perp();
        if (absrap > 1.2) continue;
        unsigned int iups = p.pid() / 100000;
        _h_pT[iups]->fill(xp);
        _h_dy_pT[iups]->fill(absrap, xp);
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      const double factor = crossSection() / femtobarn / sumOfWeights();
      const vector<double> brs = {0.0248, 0.0193, 0.0218};
      for (unsigned int ix = 0; ix < 3; ++ix) {
        scale(_h_dy_pT[ix], factor * brs[ix]); //branching ratio
        divByGroupWidth(_h_dy_pT[ix]);
        scale(_h_pT[ix], factor * brs[ix]);
      }
      for (unsigned int i = 1; i < 3; ++i) {
        Estimate1DPtr tmp;
        book(tmp, i + 3, 1, 1);
        divide(_h_dy_pT[1]->bin(i), _h_dy_pT[0]->bin(i), tmp);
        book(tmp, i + 3, 1, 2);
        divide(_h_dy_pT[2]->bin(i), _h_dy_pT[0]->bin(i), tmp);
      }
      Estimate1DPtr tmp;
      book(tmp, 6, 1, 1);
      divide(_h_pT[1], _h_pT[0], tmp);
      book(tmp, 6, 1, 2);
      divide(_h_pT[2], _h_pT[0], tmp);
    }

  private:

    Histo1DGroupPtr _h_dy_pT[3];
    Histo1DPtr _h_pT[3];
  };

  RIVET_DECLARE_PLUGIN(CMS_2015_I1342266);
}