Rivet analyses

B meson production at 7 TeV

Experiment: LHCB (LHC)

Inspire ID: 1238809

Status: VALIDATED

Authors: - Peter Richardson

References: - JHEP 08 (2013) 117

Beams: p+ p+

Beam energies: (3500.0, 3500.0)GeV

Run details: - hadronic events with B meson

Measurement of the double differential (in p_⟂ and y) cross section for B meson production at 7 TeV by the LHCb collaboration.

Source code:`LHCB_2013_I1238809.cc`

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

namespace Rivet {


  /// @brief B meson production at 7 TeV
  class LHCB_2013_I1238809 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(LHCB_2013_I1238809);


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

    /// Book histograms and initialise projections before the run
    void init() {
      declare(UnstableParticles(), "UFS");
      for(unsigned int ib=0;ib<3;++ib) {
    book(_h_sigma[ib],1,1,1+ib);
    book(_h_pT[ib]   ,5+ib,1,1);
    book(_h_y [ib]   ,8+ib,1,1);
        book(_h_B[ib],{2.0,2.5,3.0,3.5,4.0,4.5});
    for(unsigned int iy=0;iy<5;++iy) {
      book(_h_B[ib]->bin(iy+1),2+ib,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");
      for (const Particle& p : ufs.particles(Cuts::pid==511 or Cuts::pid==521 or Cuts::pid==531 )) {
        double absrap = p.absrap();
    if(absrap<2. || absrap>4.5) continue;
    unsigned int ib=(p.pid()%100)/10-1;
        double pT = p.perp();
    if(pT>40.) continue;
    _h_sigma[ib]->fill(round(sqrtS()));
    _h_B[ib]->fill(absrap,pT);
    _h_pT[ib]->fill(pT);
    _h_y[ib]->fill(absrap);
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      // 1/2 due rapidity folding +/-
      double factor = 0.5*crossSection()/microbarn/sumOfWeights();
      for(unsigned int ib=0;ib<3;++ib) {
    scale(_h_B[ib],factor);
        divByGroupWidth(_h_B[ib]);
    scale(_h_sigma[ib],factor);
    scale(_h_y    [ib],factor);
    scale(_h_pT   [ib],factor);
      }
    }

    /// @}


    /// @name Histograms
    /// @{
    BinnedHistoPtr<int> _h_sigma[3];
    Histo1DGroupPtr _h_B[3];
    Histo1DPtr _h_pT[3],_h_y[3];
    /// @}


  };


  RIVET_DECLARE_PLUGIN(LHCB_2013_I1238809);

}

Rivet analyses

B meson production at 7 TeV

Source code:LHCB_2013_I1238809.cc

Source code:`LHCB_2013_I1238809.cc`