Rivet analyses

Correlated Λc+Λ̄c production in e+e annihilations at $\sqrt{s}=10.5$ GeV

Experiment: CLEO (CESR)

Inspire ID: 552541

Status: VALIDATED

Authors: - Peter Richardson

References: - Phys.Rev. D63 (2001) 112003, 2001

Beams: e+ e-

Beam energies: (5.3, 5.3)GeV

Run details: - e+e analysis near the Υ(4S) resonance

Measurement of correlations between Λc+ and Λ̄c production in e+e annihilations at $\sqrt{s}=10.5$ GeV by the CLEO experiment. Useful fo studying models of baryon production.

Source code:CLEO_2001_I552541.cc

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

namespace Rivet {


  /// @brief Add a short analysis description here
  class CLEO_2001_I552541 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(CLEO_2001_I552541);


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

    /// Book histograms and initialise projections before the run
    void init() {

      // Initialise and register projections
      declare(UnstableParticles(), "UFS");

      book(_d_Dbar0[0], "/TMP/d_D0_low" );
      book(_d_Dbar0[1], "/TMP/d_D0_high");
      book(_d_Dm[0]   , "/TMP/d_Dm_low" );
      book(_d_Dm[1]   , "/TMP/d_Dm_high");
      book(_d_Lam[0]  , "/TMP/d_La_low" );
      book(_d_Lam[1]  , "/TMP/d_La_high");

      book(_n_Dbar0[0][0], "/TMP/d_D0_low_low"  );
      book(_n_Dbar0[0][1], "/TMP/d_D0_low_high" );
      book(_n_Dbar0[1][0], "/TMP/d_D0_high_low" );
      book(_n_Dbar0[1][1], "/TMP/d_D0_high_high");
      book(_n_Dm[0][0]   , "/TMP/d_Dm_low_low"  );
      book(_n_Dm[0][1]   , "/TMP/d_Dm_low_high" );
      book(_n_Dm[1][0]   , "/TMP/d_Dm_high_low" );
      book(_n_Dm[1][1]   , "/TMP/d_Dm_high_high");
      book(_n_Lam[0][0]  , "/TMP/d_La_low_low"  );
      book(_n_Lam[0][1]  , "/TMP/d_La_low_high" );
      book(_n_Lam[1][0]  , "/TMP/d_La_high_low" );
      book(_n_Lam[1][1]  , "/TMP/d_La_high_high");

    }

    /// Perform the per-event analysis
    void analyze(const Event& event) {
      const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
      for (const Particle& p : ufs.particles(Cuts::pid==-4122 or Cuts::pid==-411 or Cuts::pid==-421)) {
        long id1 = p.pid();
        double mom1 = p.p3().mod();
        if(mom1<2.3*GeV || mom1>5.*GeV) continue;
        bool high1 = mom1>3.3*GeV;
        if(id1==-4122) {
          _d_Lam[high1]->fill();
        }
        else if(id1==-411) {
          _d_Dm[high1]->fill();
        }
        else if(id1==-421) {
          _d_Dbar0[high1]->fill();
        }
        for (const Particle& p2 : ufs.particles(Cuts::pid==4122)) {
          if(p.p3().angle(p2.p3())<0.5*M_PI) continue;
          double mom2 = p2.p3().mod();
          if(mom2<2.3*GeV || mom2>5.*GeV) continue;
          bool high2 = mom2>3.3*GeV;
          if(id1==-4122) {
            _n_Lam[high1][high2]->fill();
          }
          else if(id1==-411) {
            _n_Dm[high1][high2]->fill();
          }
          else if(id1==-421) {
            _n_Dbar0[high1][high2]->fill();
          }
        }
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      Estimate0D R_D0_low_low    = (*_n_Dbar0[0][0]/ *_d_Dbar0[0]);
      Estimate0D R_D0_low_high   = (*_n_Dbar0[0][1]/ *_d_Dbar0[0]);
      Estimate0D R_D0_high_low   = (*_n_Dbar0[1][0]/ *_d_Dbar0[1]);
      Estimate0D R_D0_high_high  = (*_n_Dbar0[1][1]/ *_d_Dbar0[1]);
      Estimate0D R_Dm_low_low    = (*_n_Dm[0][0]   / *_d_Dm[0]);
      Estimate0D R_Dm_low_high   = (*_n_Dm[0][1]   / *_d_Dm[0]);
      Estimate0D R_Dm_high_low   = (*_n_Dm[1][0]   / *_d_Dm[1]);
      Estimate0D R_Dm_high_high  = (*_n_Dm[1][1]   / *_d_Dm[1]);
      Estimate0D R_Lam_low_low   = (*_n_Lam[0][0]  / *_d_Lam[0]);
      Estimate0D R_Lam_low_high  = (*_n_Lam[0][1]  / *_d_Lam[0]);
      Estimate0D R_Lam_high_low  = (*_n_Lam[1][0]  / *_d_Lam[1]);
      Estimate0D R_Lam_high_high = (*_n_Lam[1][1]  / *_d_Lam[1]);

      for (size_t ix=3; ix<5; ++ix) {
        for (size_t iy=1; iy<5; ++iy) {
          double num(0.),den(0.),num_err(0.),den_err(0.);
          if(ix==3) {
            if(iy==1) {
              den     =  R_D0_low_low.val();
              den_err =  R_D0_low_low.errPos();
            }
            else if(iy==2) {
              den     =  R_D0_high_low.val();
              den_err =  R_D0_high_low.errPos();
            }
            else if(iy==3) {
              den     =  R_D0_low_low.val();
              den_err =  R_D0_low_low.errPos();
            }
            else if(iy==4) {
              den     =  R_D0_high_high.val();
              den_err =  R_D0_high_high.errPos();
            }
          }
          else if(ix==4) {
            if(iy==1) {
              den     =  R_Dm_low_low.val();
              den_err =  R_Dm_low_low.errPos();
            }
            else if(iy==2) {
              den     =  R_Dm_high_low.val();
              den_err =  R_Dm_high_low.errPos();
            }
            else if(iy==3) {
              den     =  R_Dm_low_low.val();
              den_err =  R_Dm_low_low.errPos();
            }
            else if(iy==4) {
              den     =  R_Dm_high_high.val();
              den_err =  R_Dm_high_high.errPos();
            }
          }
          if(iy==1) {
            num     =  R_Lam_low_low.val();
            num_err =  R_Lam_low_low.errPos();
          }
          else if(iy==2) {
            num     =  R_Lam_high_low.val();
            num_err =  R_Lam_high_low.errPos();
          }
          else if(iy==3) {
            num     =  R_Lam_low_low.val();
            num_err =  R_Lam_low_low.errPos();
          }
          else if(iy==4) {
            num     =  R_Lam_high_high.val();
            num_err =  R_Lam_high_high.errPos();
          }
          double val = num/den;
          double err = val>=0. ? val*sqrt(sqr(num_err/num)+sqr(den_err/den)) : 0.;
          BinnedEstimatePtr<string> ratio;
          book(ratio, ix, 1, iy);
          ratio->bin(1).set(val, err);
        }
      }
    }

    /// @}


    /// @name Histograms
    /// @{
    CounterPtr _d_Dbar0[2],_d_Dm[2],_d_Lam[2];
    CounterPtr _n_Dbar0[2][2],_n_Dm[2][2],_n_Lam[2][2];
    /// @}


  };


  RIVET_DECLARE_PLUGIN(CLEO_2001_I552541);


}