rivet is hosted by Hepforge, IPPP Durham

Rivet analyses reference

BELLE_2004_I668024

Rate and spectra for the production of $\Sigma_c(2800)$
Experiment: BELLE (KEKB)
Inspire ID: 668024
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Phys.Rev.Lett. 94 (2005) 122002
Beams: e+ e-
Beam energies: (5.3, 5.3) GeV
Run details:
  • e+e- to hadrons

Measurement of the rate and scaled momentum spectra for the production of $\Sigma_c(2800)^0$, $\Sigma_c(2800)^+$ and $\Sigma_c(2800)^{++}$ baryons by BELLE.

Source code: BELLE_2004_I668024.cc
 1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/UnstableParticles.hh"
 4
 5namespace Rivet {
 6
 7
 8  /// @brief Sigma_c(2800) rate and spectra
 9  class BELLE_2004_I668024 : public Analysis {
10  public:
11
12    /// Constructor
13    RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2004_I668024);
14
15
16    /// @name Analysis methods
17    ///@{
18
19    /// Book histograms and initialise projections before the run
20    void init() {
21      // Initialise and register projections
22      declare(UnstableParticles(), "UFS");
23      // Book histograms
24      for(unsigned int ix=0;ix<3;++ix) {
25	book(_r[ix], 1, 1, 1+ix);
26	book(_h[ix], 2, 1, 1+ix);
27      }
28    }
29
30
31    /// Perform the per-event analysis
32    void analyze(const Event& event) {
33      const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
34
35      for (const Particle& p : ufs.particles()) {
36	const Vector3 mom3 = p.p3();
37	double pp = mom3.mod();
38	double xp = pp/sqrt(0.25*sqr(sqrtS())-sqr(p.mass()));
39	int id = abs(p.pid());
40	if(id==_sid+110 && isDecay(p,{4122,-211})) {
41	  _h[0]->fill(xp);
42	  _r[0]->fill(0.5);
43	}
44	else if(id==_sid+210&& isDecay(p,{4122,111})) {
45	  _h[1]->fill(xp);
46	  _r[1]->fill(0.5);
47	}
48	else if(id==_sid+220&& isDecay(p,{4122,211})) {
49	  _h[2]->fill(xp);
50	  _r[2]->fill(0.5);
51	}
52      }
53    }
54
55    // Check for explicit decay into pdgids
56    bool isDecay(const Particle& mother, vector<int> ids) {
57      if(mother.pid()<0) {
58	for(unsigned int ix=0;ix<ids.size();++ix)
59	  ids[ix] *= -1;
60      }
61      // Trivial check to ignore any other decays but the one in question modulo photons
62      const Particles children = mother.children(Cuts::pid!=PID::PHOTON);
63      if (children.size()!=ids.size()) return false;
64      // Check for the explicit decay
65      return all(ids, [&](int i){return count(children, hasPID(i))==1;});
66    }
67
68
69    /// Normalise histograms etc., after the run
70    void finalize() {
71      for(unsigned int ix=0;ix<3;++ix) {
72	normalize(_h[ix]);
73	scale(_r[ix], crossSection()/picobarn/sumOfWeights());
74      }
75    }
76
77    ///@}
78
79
80    /// @name Histograms
81    ///@{
82    Histo1DPtr _h[3],_r[3];
83    static const int _sid = 14002;
84    ///@}
85
86
87  };
88
89
90  RIVET_DECLARE_PLUGIN(BELLE_2004_I668024);
91
92}