Rivet analyses

Differential branching ratio w.r.t. q2 for Λ0b → Λ(1520)0μ+μ−

Experiment: LHCB (LHC)

Inspire ID: 2633007

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - arXiv: 2302.08262

Beams: * *

Beam energies: ANY

Run details: - Any process producing Lambda_b0 baryons, originally pp

Measurement of the differential branching ratio w.r.t. q2 for Λ0b → Λ(1520)0μ+μ−. The data were taken from the table in the paper.

Source code:LHCB_2023_I2633007.cc

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

namespace Rivet {


  /// @brief Lambdab0 -> Lambda(1520) mu+mu-
  class LHCB_2023_I2633007 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(LHCB_2023_I2633007);


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

    /// Book histograms and initialise projections before the run
    void init() {
      // Initialise and register projections
      UnstableParticles ufs = UnstableParticles(Cuts::abspid == 5122);
      declare(ufs, "UFS");
      DecayedParticles BB(ufs);
      BB.addStable(102134);
      BB.addStable(-102134);
      declare(BB, "BB");
      // histos
      for (unsigned int ix = 0; ix < 2; ++ix) {
        book(_h[ix], 1, 1 + ix, 1);
      }
      book(_c, "TMP/nLambdab");
    }


    /// Perform the per-event analysis
    void analyze(const Event& event) {
      static const map<PdgId, unsigned int> mode = {{102134, 1}, {13, 1}, {-13, 1}};
      static const map<PdgId, unsigned int> modeCC = {{-102134, 1}, {13, 1}, {-13, 1}};
      DecayedParticles BB = apply<DecayedParticles>(event, "BB");
      // loop over particles
      for (unsigned int ix = 0; ix < BB.decaying().size(); ++ix) {
        _c->fill();
        if (!((BB.decaying()[ix].pid() > 0 && BB.modeMatches(ix, 3, mode))
              || (BB.decaying()[ix].pid() < 0 && BB.modeMatches(ix, 3, modeCC))))
          continue;
        const Particle& lp = BB.decayProducts()[ix].at(-13)[0];
        const Particle& lm = BB.decayProducts()[ix].at(13)[0];
        const double qq = (lp.mom() + lm.mom()).mass2();
        _h[0]->fill(qq);
        _h[1]->fill(qq);
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      scale(_h, 1e8 / *_c);
    }

    /// @}


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


  RIVET_DECLARE_PLUGIN(LHCB_2023_I2633007);

}