rivet is hosted by Hepforge, IPPP Durham

Rivet analyses reference

BELLE_2019_I1762826

Cross section for $e^+e^-\to D_s^+D_{s1}(2536)^-\text{c.c.}$ between 4.52 and 5.6 GeV
Experiment: BELLE (KEKB)
Inspire ID: 1762826
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Phys.Rev.D 100 (2019) 11, 111103
Beams: e+ e-
Beam energies: ANY
Run details:
  • e+ e- to hadrons

Measurement of the cross section for $e^+e^-\to D_s^+D_{s1}(2536)^-\text{c.c.}$ times the branching ratio for $D_{s1}(2536)^-\to \bar{D}^{*0}K^-$ for centre-of-mass energies between 4.52 and 5.6 GeV by the BELLE collaboration.

Source code: BELLE_2019_I1762826.cc
  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/FinalState.hh"
#include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {


  /// @brief  e+e- -> Ds D_s1
  class BELLE_2019_I1762826 : public Analysis {
  public:

    /// Constructor
    DEFAULT_RIVET_ANALYSIS_CTOR(BELLE_2019_I1762826);


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

    /// Book histograms and initialise projections before the run
    void init() {
      // Initialise and register projections
      declare(FinalState(), "FS");
      declare(UnstableParticles(), "UFS");

      // Book histograms
      book(_c_Ds    ,"/TMP/c_Ds"    );
    }

    void findChildren(const Particle & p,map<long,int> & nRes, int &ncount) {
      for(const Particle &child : p.children()) {
	if(child.children().empty()) {
	  nRes[child.pid()]-=1;
	  --ncount;
	}
	else
	  findChildren(child,nRes,ncount);
      }
    }

    /// Perform the per-event analysis
    void analyze(const Event& event) {
      const FinalState& fs = apply<FinalState>(event, "FS");
      // total analyse final state
      map<long,int> nCount;
      int ntotal(0);
      for (const Particle& p : fs.particles()) {
      	nCount[p.pid()] += 1;
      	++ntotal;
      }
      // unstable charm analysis
      Particles ds = apply<UnstableParticles>(event, "UFS").particles(Cuts::abspid==431 or Cuts::abspid==10433);
      for(unsigned int ix=0;ix<ds.size();++ix) {
	const Particle& p1 = ds[ix];
       	int id1 = abs(p1.pid());
	// check fs
	bool fs = true;
	for (const Particle & child : p1.children()) {
	  if(child.pid()==p1.pid()) {
	    fs = false;
	    break;
	  }
	}
      	if(!fs) continue;
      	// find the children
      	map<long,int> nRes = nCount;
      	int ncount = ntotal;
      	findChildren(p1,nRes,ncount);
      	bool matched=false;
       	int sign = p1.pid()/id1;
       	for(unsigned int iy=ix+1;iy<ds.size();++iy) {
      	  const Particle& p2 = ds[iy];
      	  fs = true;
      	  for (const Particle & child : p2.children()) {
      	    if(child.pid()==p2.pid()) {
      	      fs = false;
      	      break;
      	    }
      	  }
      	  if(!fs) continue;
      	  if(p2.pid()/abs(p2.pid())==sign) continue;
	  int id2 = abs(p2.pid());
	  if(!p2.parents().empty() && p2.parents()[0].pid()==p1.pid())
	    continue;
	  map<long,int> nRes2 = nRes;
	  int ncount2 = ncount;
	  findChildren(p2,nRes2,ncount2);
	  if(ncount2!=0) continue;
	  matched=true;
	  for(auto const & val : nRes2) {
	    if(val.second!=0) {
	      matched = false;
	      break;
	    }
	  }
	  if(matched) {
       	    if((id1==431 && id2==10433) || (id1==10433 && id2==431)) {
	      Particle Ds2 = id1==10433 ? p1 : p2;
	      matched = false;
	      if(Ds2.children().size()!=2) continue;
	      if(Ds2.pid()==10433 &&
		 ((Ds2.children()[0].pid()==423 && Ds2.children()[1].pid()==321) ||
		  (Ds2.children()[1].pid()==423 && Ds2.children()[0].pid()==321) ))
		matched = true;
	      else if (Ds2.pid()==-10433 &&
		 ((Ds2.children()[0].pid()==-423 && Ds2.children()[1].pid()==-321) ||
		  (Ds2.children()[1].pid()==-423 && Ds2.children()[0].pid()==-321) ))
		matched = true;
	      if(matched) {
		_c_Ds->fill();
		break;
	      }
	    }
	  }
	}
	if(matched) break;
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      double fact = crossSection()/ sumOfWeights()/picobarn;
      double sigma = _c_Ds->val()*fact;
      double error = _c_Ds->err()*fact;
      Scatter2D temphisto(refData(1, 1, 1));
      Scatter2DPtr     mult;
      book(mult, 1, 1, 1);
      for (size_t b = 0; b < temphisto.numPoints(); b++) {
	const double x  = temphisto.point(b).x();
	pair<double,double> ex = temphisto.point(b).xErrs();
	pair<double,double> ex2 = ex;
	if(ex2.first ==0.) ex2. first=0.0001;
	if(ex2.second==0.) ex2.second=0.0001;
	if (inRange(sqrtS()/GeV, x-ex2.first, x+ex2.second)) {
	  mult   ->addPoint(x, sigma, ex, make_pair(error,error));
	}
	else {
	  mult   ->addPoint(x, 0., ex, make_pair(0.,.0));
	}
      }
    }

    ///@}


    /// @name Histograms
    ///@{
    CounterPtr _c_Ds;
    ///@}


  };


  DECLARE_RIVET_PLUGIN(BELLE_2019_I1762826);

}