Rivet analyses

Mass distributions in B_c⁺ → J/ψ+ π⁺π⁺π⁻, K⁺K⁻π⁺ and K⁺π⁺π⁻

Experiment: LHCB (LHC)

Inspire ID: 1960979

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - JHEP 01 (2022) 065

Beams: * *

Beam energies: ANY

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

Mass distributions in B_c⁺ → J/ψ+ π⁺π⁺π⁻, K⁺K⁻π⁺ and K⁺π⁺π⁻. The data were read from the plots in the paper and may not be corrected for efficiency and acceptance.

Source code:`LHCB_2022_I1960979.cc`

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

namespace Rivet {


  /// @brief B_c - > jpsi + 3 charged hadrons
  class LHCB_2022_I1960979 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(LHCB_2022_I1960979);


    /// @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 < 4; ++ix) {
        for (unsigned int iy = 0; iy < 2; ++iy) {
          if (iy == 1 && ix > 1) continue;
          book(_h[ix][iy], 1 + ix, 1, 1 + iy);
        }
      }
    }


    /// Perform the per-event analysis
    void analyze(const Event& event) {
      static const map<PdgId, unsigned int>& mode1 = {{443, 1}, {211, 2}, {-211, 1}};
      static const map<PdgId, unsigned int>& mode1CC = {{443, 1}, {-211, 2}, {211, 1}};
      static const map<PdgId, unsigned int>& mode2 = {{443, 1}, {321, 1}, {-321, 1}, {211, 1}};
      static const map<PdgId, unsigned int>& mode2CC = {{443, 1}, {321, 1}, {-321, 1}, {-211, 1}};
      static const map<PdgId, unsigned int>& mode3 = {{443, 1}, {211, 1}, {-211, 1}, {321, 1}};
      static const map<PdgId, unsigned int>& mode3CC = {{443, 1}, {211, 1}, {-211, 1}, {-321, 1}};
      static const map<PdgId, unsigned int>& mode4 = {{443, 1}, {321, 2}, {-321, 1}};
      static const map<PdgId, unsigned int>& mode4CC = {{443, 1}, {321, 1}, {-321, 2}};
      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, mode1)) || (sign == -1 && BC.modeMatches(ix, 4, mode1CC))) {
          const Particle& pim = BC.decayProducts()[ix].at(-sign * 211)[0];
          const Particles& pip = BC.decayProducts()[ix].at(sign * 211);
          _h[0][0]->fill((pim.momentum() + pip[0].momentum() + pip[1].momentum()).mass());
          _h[0][1]->fill((pim.momentum() + pip[0].momentum()).mass());
          _h[0][1]->fill((pim.momentum() + pip[1].momentum()).mass());
        }
        else if ((sign == 1 && BC.modeMatches(ix, 4, mode2))
                 || (sign == -1 && BC.modeMatches(ix, 4, mode2CC))) {
          const Particle& Kp = BC.decayProducts()[ix].at(sign * 321)[0];
          const Particle& Km = BC.decayProducts()[ix].at(-sign * 321)[0];
          const Particle& pip = BC.decayProducts()[ix].at(sign * 211)[0];
          _h[1][0]->fill((Km.momentum() + pip.momentum()).mass());
          _h[1][1]->fill((Km.momentum() + Kp.momentum()).mass());
        }
        else if ((sign == 1 && BC.modeMatches(ix, 4, mode3))
                 || (sign == -1 && BC.modeMatches(ix, 4, mode3CC))) {
          const Particle& pim = BC.decayProducts()[ix].at(-sign * 211)[0];
          const Particle& Kp = BC.decayProducts()[ix].at(sign * 321)[0];
          _h[2][0]->fill((Kp.momentum() + pim.momentum()).mass());
        }
        else if ((sign == 1 && BC.modeMatches(ix, 4, mode4))
                 || (sign == -1 && BC.modeMatches(ix, 4, mode4CC))) {
          const Particle& Km = BC.decayProducts()[ix].at(-sign * 321)[0];
          const Particles& Kp = BC.decayProducts()[ix].at(sign * 321);
          _h[3][0]->fill((Kp[0].momentum() + Km.momentum()).mass());
          _h[3][0]->fill((Kp[1].momentum() + Km.momentum()).mass());
        }
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      for (unsigned int ix = 0; ix < 3; ++ix) {
        for (unsigned int iy = 0; iy < 2; ++iy) {
          if (iy == 1 && ix > 1) continue;
          normalize(_h[ix][iy], 1., false);
        }
      }
    }

    /// @}


    /// @name Histograms
    /// @{
    Histo1DPtr _h[4][2];
    /// @}
  };


  RIVET_DECLARE_PLUGIN(LHCB_2022_I1960979);

}

Rivet analyses

Mass distributions in Bc+ → J/ψ+ π+π+π−, K+K−π+ and K+π+π−

Source code:LHCB_2022_I1960979.cc

Mass distributions in B_c⁺ → J/ψ+ π⁺π⁺π⁻, K⁺K⁻π⁺ and K⁺π⁺π⁻

Source code:`LHCB_2022_I1960979.cc`