Rivet analyses

Mass distributions in B_c⁺ → J/ψpp̄π⁺

Experiment: LHCB (LHC)

Inspire ID: 1309880

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev.Lett. 113 (2014) 15, 152003

Beams: * *

Beam energies: ANY

Run details: - Any process producing B_c+, originally pp

Mass distributions in B_c⁺ → J/ψpp̄π⁺. The data were extracted from the plots in the paper and may not be corrected for efficiency and acceptance.

Source code:`LHCB_2014_I1309880.cc`

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

namespace Rivet {


  /// @brief B_c -> J/psi p pbar pi+
  class LHCB_2014_I1309880 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(LHCB_2014_I1309880);


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

    /// Book histograms and initialise projections before the run
    void init() {
      UnstableParticles ufs = UnstableParticles(Cuts::abspid == 541);
      declare(ufs, "UFS");
      DecayedParticles BC(ufs);
      BC.addStable(PID::PI0);
      BC.addStable(PID::K0S);
      BC.addStable(PID::JPSI);
      declare(BC, "BC");
      for (unsigned int ix = 0; ix < 2; ++ix) book(_h[ix], 1, 1, 1 + ix);
    }


    /// Perform the per-event analysis
    void analyze(const Event& event) {
      static const map<PdgId, unsigned int>& mode = {{443, 1}, {2212, 1}, {2212, 1}, {211, 1}};
      static const map<PdgId, unsigned int>& modeCC = {{443, 1}, {2212, 1}, {2212, 1}, {-211, 1}};
      DecayedParticles BC = apply<DecayedParticles>(event, "BC");
      // loop over particles
      for (unsigned int ix = 0; ix < BC.decaying().size(); ++ix) {
        int sign = BC.decaying()[ix].pid() / BC.decaying()[ix].abspid();
        if ((sign == 1 && BC.modeMatches(ix, 4, mode)) || (sign == -1 && BC.modeMatches(ix, 4, modeCC))) {
          const Particle& prot = BC.decayProducts()[ix].at(sign * 2212)[0];
          const Particle& pbar = BC.decayProducts()[ix].at(-sign * 2212)[0];
          const Particle& pip = BC.decayProducts()[ix].at(sign * 211)[0];
          _h[0]->fill((prot.momentum() + pbar.momentum()).mass());
          _h[1]->fill((prot.momentum() + pip.momentum()).mass());
        }
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      for (unsigned int ix = 0; ix < 2; ++ix) normalize(_h[ix], 1., false);
    }

    /// @}


    /// @name Histograms
    /// @{
    Histo1DPtr _h[2];
    /// @}
  };


  RIVET_DECLARE_PLUGIN(LHCB_2014_I1309880);

}

Rivet analyses

Mass distributions in Bc+ → J/ψpp̄π+

Source code:LHCB_2014_I1309880.cc

Mass distributions in B_c⁺ → J/ψpp̄π⁺

Source code:`LHCB_2014_I1309880.cc`