Rivet analyses referenceMARKII_1985_I209198$\Lambda^0$ production at 29 GeVExperiment: MARKII (PEP) Inspire ID: 209198 Status: VALIDATED Authors:
Beam energies: (14.5, 14.5) GeV Run details:
Spectrum and $p_T$ with respect to the thrust axis for $\Lambda^0$ baryon production at 29 GeV measured by the MARKII collaboration. Source code: MARKII_1985_I209198.cc 1// -*- C++ -*-
2#include "Rivet/Analysis.hh"
3#include "Rivet/Projections/UnstableParticles.hh"
4#include "Rivet/Projections/FinalState.hh"
5#include "Rivet/Projections/ChargedFinalState.hh"
6#include "Rivet/Projections/Thrust.hh"
7
8namespace Rivet {
9
10
11 /// @brief Lambda0 production at 29 GeV
12 class MARKII_1985_I209198 : public Analysis {
13 public:
14
15 /// Constructor
16 RIVET_DEFAULT_ANALYSIS_CTOR(MARKII_1985_I209198);
17
18
19 /// @name Analysis methods
20 ///@{
21
22 /// Book histograms and initialise projections before the run
23 void init() {
24 // Initialise and register projections
25 declare(UnstableParticles(), "UFS");
26 const ChargedFinalState cfs;
27 declare(cfs, "CFS");
28 const FinalState fs;
29 declare(cfs, "FS");
30 declare(Thrust(fs), "Thrust");
31 //Histograms
32 book(_h_spect,2,1,1);
33 book(_h_pT ,3,1,1);
34 }
35
36
37 /// Perform the per-event analysis
38 void analyze(const Event& event) {
39 // 5 charged particles
40 const ChargedFinalState& cfs = apply<ChargedFinalState>(event, "CFS");
41 if(cfs.particles().size()<5) vetoEvent;
42 // thrust
43 const Thrust& thrust = apply<Thrust>(event, "Thrust");
44 // lambdas
45 const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
46 for (const Particle& p : ufs.particles(Cuts::abspid==3122)) {
47 const double xp = 2.*p.E()/sqrtS();
48 Vector3 mom3 = p.p3();
49 const double beta = mom3.mod() / p.E();
50 const double pTin = dot(mom3, thrust.thrustMajorAxis());
51 const double pTout = dot(mom3, thrust.thrustMinorAxis());
52 double pT2 = sqr(pTin)+sqr(pTout);
53 _h_spect->fill(xp,1./beta);
54 _h_pT ->fill(pT2);
55 }
56 }
57
58
59 /// Normalise histograms etc., after the run
60 void finalize() {
61 scale(_h_spect, sqr(sqrtS())*crossSection()/nanobarn/sumOfWeights());
62 normalize(_h_pT);
63 }
64
65 ///@}
66
67
68 /// @name Histograms
69 ///@{
70 Histo1DPtr _h_spect,_h_pT;
71 ///@}
72
73
74 };
75
76
77 RIVET_DECLARE_PLUGIN(MARKII_1985_I209198);
78
79}
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