Rivet analyses referenceCLEO_2004_S5809304Charm hadrons from fragmentation near the $\Upsilon(4S)$Experiment: CLEO (CESR) Inspire ID: 645209 Status: VALIDATED Authors:
Beam energies: (5.3, 5.3) GeV Run details:
Analysis of charm quark fragmentation at 10.5 GeV, based on a data sample of 103 fb collected by the CLEO experiment. Fragmentation into charm is studied for the charmed hadron ground states, namely $D^0$, $D^+$, as well as the excited states $D^{*0}$ and $D^{*+}$. This analysis can be used to constrain charm fragmentation in Monte Carlo generators. Source code: CLEO_2004_S5809304.cc 1// -*- C++ -*-
2#include "Rivet/Analysis.hh"
3#include "Rivet/Projections/Beam.hh"
4#include "Rivet/Projections/UnstableParticles.hh"
5
6namespace Rivet {
7
8
9 /// @brief CLEO charmed mesons and baryons from fragmentation
10 ///
11 /// @author Peter Richardson
12 class CLEO_2004_S5809304 : public Analysis {
13 public:
14
15 RIVET_DEFAULT_ANALYSIS_CTOR(CLEO_2004_S5809304);
16
17 void init() {
18 declare(Beam(), "Beams");
19 declare(UnstableParticles(), "UFS");
20
21 // continuum cross sections
22 book(_sigmaDPlus ,1,1,1);
23 book(_sigmaD0A ,1,1,2);
24 book(_sigmaD0B ,1,1,3);
25 book(_sigmaDStarPlusA ,1,1,4);
26 book(_sigmaDStarPlusB ,1,1,5);
27 book(_sigmaDStar0A ,1,1,6);
28 book(_sigmaDStar0B ,1,1,7);
29
30 // histograms for continuum data
31 book(_histXpDplus ,2, 1, 1);
32 book(_histXpD0A ,3, 1, 1);
33 book(_histXpD0B ,4, 1, 1);
34 book(_histXpDStarPlusA ,5, 1, 1);
35 book(_histXpDStarPlusB ,6, 1, 1);
36 book(_histXpDStar0A ,7, 1, 1);
37 book(_histXpDStar0B ,8, 1, 1);
38 book(_histXpTotal ,9, 1, 1);
39
40 }
41
42
43 void analyze(const Event& e) {
44 // Loop through unstable FS particles and look for charmed mesons/baryons
45 const UnstableParticles& ufs = apply<UnstableParticles>(e, "UFS");
46
47 const Beam beamproj = apply<Beam>(e, "Beams");
48 const ParticlePair& beams = beamproj.beams();
49 const FourMomentum mom_tot = beams.first.momentum() + beams.second.momentum();
50 LorentzTransform cms_boost;
51 if (mom_tot.p3().mod() > 1*MeV)
52 cms_boost = LorentzTransform::mkFrameTransformFromBeta(mom_tot.betaVec());
53 const double s = sqr(beamproj.sqrtS());
54
55 // Particle masses from PDGlive (accessed online 16. Nov. 2009).
56 for (const Particle& p : ufs.particles()) {
57
58 double xp = 0.0;
59 double mH2 = 0.0;
60 // 3-momentum in CMS frame
61 const double mom = cms_boost.transform(p.momentum()).vector3().mod();
62
63 const int pdgid = p.abspid();
64 MSG_DEBUG("pdgID = " << pdgid << " mom = " << mom);
65 switch (pdgid) {
66
67 case 421:
68 MSG_DEBUG("D0 found");
69 mH2 = 3.47763; // 1.86484^2
70 xp = mom/sqrt(s/4.0 - mH2);
71 _sigmaD0A->fill(10.6);
72 _sigmaD0B->fill(10.6);
73 _histXpD0A->fill(xp);
74 _histXpD0B->fill(xp);
75 _histXpTotal->fill(xp);
76 break;
77
78 case 411:
79 MSG_DEBUG("D+ found");
80 mH2 = 3.49547; // 1.86962^2
81 xp = mom/sqrt(s/4.0 - mH2);
82 _sigmaDPlus->fill(10.6);
83 _histXpDplus->fill(xp);
84 _histXpTotal->fill(xp);
85 break;
86
87 case 413:
88 MSG_DEBUG("D*+ found");
89 mH2 = 4.04119; // 2.01027^2
90 xp = mom/sqrt(s/4.0 - mH2);
91 _sigmaDStarPlusA->fill(10.6);
92 _sigmaDStarPlusB->fill(10.6);
93 _histXpDStarPlusA->fill(xp);
94 _histXpDStarPlusB->fill(xp);
95 _histXpTotal->fill(xp);
96 break;
97
98 case 423:
99 MSG_DEBUG("D*0 found");
100 mH2 = 4.02793; // 2.00697**2
101 xp = mom/sqrt(s/4.0 - mH2);
102 _sigmaDStar0A->fill(10.6);
103 _sigmaDStar0B->fill(10.6);
104 _histXpDStar0A->fill(xp);
105 _histXpDStar0B->fill(xp);
106 _histXpTotal->fill(xp);
107 break;
108 }
109
110 }
111 }
112
113
114 void finalize() {
115
116 scale(_sigmaDPlus , crossSection()/picobarn/sumOfWeights());
117 scale(_sigmaD0A , crossSection()/picobarn/sumOfWeights());
118 scale(_sigmaD0B , crossSection()/picobarn/sumOfWeights());
119 scale(_sigmaDStarPlusA, crossSection()/picobarn/sumOfWeights());
120 scale(_sigmaDStarPlusB, crossSection()/picobarn/sumOfWeights());
121 scale(_sigmaDStar0A , crossSection()/picobarn/sumOfWeights());
122 scale(_sigmaDStar0B , crossSection()/picobarn/sumOfWeights());
123
124 scale(_histXpDplus , crossSection()/picobarn/sumOfWeights());
125 scale(_histXpD0A , crossSection()/picobarn/sumOfWeights());
126 scale(_histXpD0B , crossSection()/picobarn/sumOfWeights());
127 scale(_histXpDStarPlusA, crossSection()/picobarn/sumOfWeights());
128 scale(_histXpDStarPlusB, crossSection()/picobarn/sumOfWeights());
129 scale(_histXpDStar0A , crossSection()/picobarn/sumOfWeights());
130 scale(_histXpDStar0B , crossSection()/picobarn/sumOfWeights());
131 scale(_histXpTotal , crossSection()/picobarn/sumOfWeights()/4.);
132 }
133
134
135 private:
136
137 // Histograms for the continuum cross sections
138 Histo1DPtr _sigmaDPlus ;
139 Histo1DPtr _sigmaD0A ;
140 Histo1DPtr _sigmaD0B ;
141 Histo1DPtr _sigmaDStarPlusA;
142 Histo1DPtr _sigmaDStarPlusB;
143 Histo1DPtr _sigmaDStar0A ;
144 Histo1DPtr _sigmaDStar0B ;
145
146 // Histograms for continuum data
147 Histo1DPtr _histXpDplus ;
148 Histo1DPtr _histXpD0A ;
149 Histo1DPtr _histXpD0B ;
150 Histo1DPtr _histXpDStarPlusA;
151 Histo1DPtr _histXpDStarPlusB;
152 Histo1DPtr _histXpDStar0A ;
153 Histo1DPtr _histXpDStar0B ;
154 Histo1DPtr _histXpTotal ;
155
156 };
157
158
159 RIVET_DECLARE_ALIASED_PLUGIN(CLEO_2004_S5809304, CLEO_2004_I645209);
160
161}
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