Rivet analyses referenceARGUS_1992_I334962Proton and $\Lambda$ momentum spectrum in B decaysExperiment: ARGUS (DORIS) Inspire ID: 334962 Status: VALIDATED NOHEPDATA Authors:
Beam energies: ANY Run details:
Measurement of the proton and $\Lambda$ momentum spectrum in B decays by ARGUS. The corrected data were read from the figures in the paper. Source code: ARGUS_1992_I334962.cc 1// -*- C++ -*-
2#include "Rivet/Analysis.hh"
3#include "Rivet/Projections/UnstableParticles.hh"
4
5namespace Rivet {
6
7
8 /// @brief B-> baryons
9 class ARGUS_1992_I334962 : public Analysis {
10 public:
11
12 /// Constructor
13 RIVET_DEFAULT_ANALYSIS_CTOR(ARGUS_1992_I334962);
14
15
16 /// @name Analysis methods
17 /// @{
18
19 /// Book histograms and initialise projections before the run
20 void init() {
21 // projections
22 declare(UnstableParticles(), "UFS");
23 // histos
24 for (unsigned int ix=0; ix < 2; ++ix) {
25 book(_h_spect[ix],1+ix,1,1);
26 book(_h_flav [ix],3,1,1+ix);
27 }
28 }
29
30 void findDecayProducts(const Particle& parent, Particles& protons_all, Particles& protons_charm,
31 Particles& protons_had, Particles & lambda, bool cBaryon=false) {
32 for (const Particle& p : parent.children()) {
33 if (p.abspid() == PID::PROTON) {
34 protons_all.push_back(p);
35 if (cBaryon) protons_charm.push_back(p);
36 else protons_had .push_back(p);
37 }
38 else if (p.abspid()== PID::LAMBDA) {
39 lambda.push_back(p);
40 continue;
41 }
42 else if (!p.children().empty()) {
43 bool cBaryonDec = cBaryon || ( PID::isCharmHadron(p.pid()) && p.abspid()%2==0);
44 findDecayProducts(p,protons_all,protons_charm,protons_had,lambda,cBaryonDec);
45 }
46 }
47 }
48
49
50 /// Perform the per-event analysis
51 void analyze(const Event& event) {
52 // Find the upsilons
53 for (const Particle& ups : apply<UnstableParticles>(event, "UFS").particles(Cuts::pid==300553)) {
54 Particles protons[3],lambda;
55 findDecayProducts(ups,protons[0],protons[1],protons[2],lambda);
56 LorentzTransform boost;
57 if (ups.p3().mod() > 1*MeV) {
58 boost = LorentzTransform::mkFrameTransformFromBeta(ups.mom().betaVec());
59 }
60 for (const Particle& p : protons[0]) {
61 double pcm = boost.transform(p.mom()).p3().mod();
62 _h_spect[0]->fill(pcm);
63 }
64 for (const Particle& p : lambda) {
65 double pcm = boost.transform(p.mom()).p3().mod();
66 _h_spect[1]->fill(pcm);
67 }
68 for (unsigned int ix=0; ix<2; ++ix) {
69 for (const Particle& p : protons[ix+1]) {
70 double pcm = boost.transform(p.mom()).p3().mod();
71 _h_flav[ix]->fill(pcm);
72 }
73 }
74 }
75 }
76
77
78 /// Normalise histograms etc., after the run
79 void finalize() {
80 normalize(_h_spect, 1.0, false);
81 normalize(_h_flav , 1.0, false);
82 }
83
84 /// @}
85
86
87 /// @name Histograms
88 /// @{
89 Histo1DPtr _h_spect[2], _h_flav[2];
90 /// @}
91
92
93 };
94
95
96 RIVET_DECLARE_PLUGIN(ARGUS_1992_I334962);
97
98}
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