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BELLE_2019_I1718551

Cross sections for $\pi^\pm$, $K^\pm$ and $p\bar{p}$ as functions of $z$ and $p_\perp$ at $E_{\text{cms}}=10.58$ GeV
Experiment: BELLE (KEKB)
Inspire ID: 1718551
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Phys.Rev. D92 (2015) no.9, 092007
Beams: e+ e-
Beam energies: (5.3, 5.3) GeV
Run details:
  • e+e- to hadrons at 10.58 continuum events only

Cross sections for $\pi^\pm$, $K^\pm$ and $p\bar{p}$ as functions of $z$ and $p_\perp$ at $E_{\text{cms}}=10.58$ GeV

Source code: BELLE_2019_I1718551.cc
  1// -*- C++ -*-
  2#include "Rivet/Analysis.hh"
  3#include "Rivet/Projections/FinalState.hh"
  4#include "Rivet/Projections/Thrust.hh"
  5#include "Rivet/Projections/Beam.hh"
  6
  7namespace Rivet {
  8
  9
 10  /// @brief pi, kaon and proton spectra at 10.58 GeV
 11  class BELLE_2019_I1718551 : public Analysis {
 12  public:
 13
 14    /// Constructor
 15    RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2019_I1718551);
 16
 17
 18    /// @name Analysis methods
 19    //@{
 20
 21    /// Book histograms and initialise projections before the run
 22    void init() {
 23      // projections
 24      const FinalState fs;
 25      declare(fs, "FS");
 26      declare(Thrust(fs),"Thrust");
 27      declare(Beam(), "Beams");
 28
 29      for(unsigned int ix=0;ix<6;++ix) {
 30	double xmin=0.05;
 31	for(unsigned int iy=0;iy<18;++iy) {
 32	  xmin+=0.05;
 33	  // pions
 34	  if(ix==0&&iy>15) continue;
 35	  Histo1DPtr temp1;
 36	  book(temp1,1,ix+1,iy+1);
 37	  _pion[ix].add(xmin,xmin+0.05,temp1);
 38	  // kaons
 39	  Histo1DPtr temp2;
 40	  book(temp2,2,ix+1,iy+1);
 41	  _kaon[ix].add(xmin,xmin+0.05,temp2);
 42	  if(iy>15 || (iy>14&&ix<3) || (iy>11&&ix==0)) continue;
 43	  // protons
 44	  Histo1DPtr temp3;
 45	  book(temp3,3,ix+1,iy+1);
 46	  _proton[ix].add(xmin,xmin+0.05,temp3);
 47	}
 48      }
 49    }
 50
 51
 52    /// Perform the per-event analysis
 53    void analyze(const Event& event) {
 54      // Get beams and average beam momentum
 55      const ParticlePair& beams = apply<Beam>(event, "Beams").beams();
 56      const double meanBeamMom = ( beams.first.p3().mod() +
 57                                   beams.second.p3().mod() ) / 2.0;
 58      // get the thrust 
 59      const double tbins[6]={0.7,0.8,0.85,0.9,0.95,1.0};
 60      const Thrust& thrust = apply<Thrust>(event, "Thrust");
 61      // find the thrust bin
 62      unsigned int ithrust=0;
 63      for(;ithrust<6;++ithrust)
 64	if(thrust.thrust()<=tbins[ithrust]) break;
 65      Vector3 a1 = thrust.thrustMajorAxis();
 66      Vector3 a2 = thrust.thrustMinorAxis();
 67      // loop over the charged hadrons
 68      const FinalState & fs = apply<FinalState>(event, "FS");
 69      for(const Particle & charged : fs.particles(Cuts::abspid==211 or
 70						  Cuts::abspid==321 or
 71						  Cuts::abspid==2212)) {
 72	double xE = charged.momentum().t()/meanBeamMom;
 73	double pT = sqrt(sqr(a1.dot(charged.momentum().p3()))+
 74			 sqr(a2.dot(charged.momentum().p3())));
 75	if(charged.abspid()==211)
 76	  _pion  [ithrust].fill(xE,pT);
 77	else if(charged.abspid()==321)
 78	  _kaon  [ithrust].fill(xE,pT);
 79	else if(charged.abspid()==2212)
 80	  _proton[ithrust].fill(xE,pT);
 81      }
 82    }
 83
 84
 85    /// Normalise histograms etc., after the run
 86    void finalize() {
 87      // scale factor including bin width in x_E
 88      double fact = crossSection()/femtobarn/sumOfWeights()/0.05;
 89      for(unsigned int ix=0;ix<6;++ix) {
 90	for(Histo1DPtr histo : _pion  [ix].histos()) scale(histo,fact);
 91	for(Histo1DPtr histo : _kaon  [ix].histos()) scale(histo,fact);
 92	for(Histo1DPtr histo : _proton[ix].histos()) scale(histo,fact);
 93      }
 94    }
 95
 96    //@}
 97
 98
 99    /// @name Histograms
100    //@{
101    BinnedHistogram _pion[6],_kaon[6],_proton[6];
102    //@}
103
104
105  };
106
107
108  RIVET_DECLARE_PLUGIN(BELLE_2019_I1718551);
109
110}