Rivet analyses referenceE605_1991_I302822Dimuon production in proton-copper collisions at $\sqrt{s} = 38.8$ GeVExperiment: E605 (Fermilab) Inspire ID: 302822 Status: VALIDATED No authors listed References:
Beam energies: (19.4, 19.4) GeV
Experimental results on the production of dimuons by 800-GeV protons incident on a copper target are presented. The results include measurements of both the continuum of dimuons and the dimuon decays of the three lowest-mass $\Upsilon$ states. Source code: E605_1991_I302822.cc 1// -*- C++ -*-
2#include "Rivet/Analysis.hh"
3#include "Rivet/Projections/FinalState.hh"
4#include "Rivet/Projections/FastJets.hh"
5#include "Rivet/Projections/ZFinder.hh"
6
7namespace Rivet {
8
9
10 /// Dimuon production in proton-copper collisions at 38.8 GeV
11 class E605_1991_I302822 : public Analysis {
12 public:
13
14 /// Constructor
15 RIVET_DEFAULT_ANALYSIS_CTOR(E605_1991_I302822);
16
17
18 /// @name Analysis methods
19 //@{
20
21 /// Book histograms and initialise projections before the run
22 void init() {
23
24 // Initialise and register projections
25 const FinalState fs;
26 declare(fs, "FS");
27 Cut cut = Cuts::etaIn(-10.,10.);
28 ZFinder zfinder(fs, cut, PID::MUON, 4.0*GeV, 100.0*GeV, 0.1, ZFinder::ClusterPhotons::NONE );
29 declare(zfinder, "ZFinder");
30
31 // Book histograms in mass ranges (measurement is not normalised to mass range)
32 Histo1DPtr dummy;
33 book(_hist_pT_M_78,17, 1, 1);
34 book(_hist_pT_M_89,18, 1, 1);
35 book(_hist_pT_M_1011,19, 1, 1);
36 book(_hist_pT_M_1113,20, 1, 1);
37 book(_hist_pT_M_1318,21, 1, 1);
38
39 int Nbin = 50;
40 book(_h_m_DiMuon,"DiMuon_mass",Nbin,0.0,30.0);
41 book(_h_pT_DiMuon,"DiMuon_pT",Nbin,0.0,20.0);
42 book(_h_y_DiMuon,"DiMuon_y",Nbin,-8.0, 8.0);
43 book(_h_xF_DiMuon,"DiMuon_xF",Nbin, -1.5, 1.5);
44
45 }
46
47
48 /// Perform the per-event analysis
49 void analyze(const Event& event) {
50
51 const double sqrts_tol = 10. ;
52 if (!isCompatibleWithSqrtS(38.8, sqrts_tol)) {
53 MSG_ERROR("Incorrect beam energy used: " << sqrtS()/GeV);
54 throw Error("Unexpected sqrtS ! Only 38.8 GeV is supported");
55 }
56
57 const ZFinder& zfinder = applyProjection<ZFinder>(event, "ZFinder");
58 if (zfinder.particles().size() >= 1) {
59
60 double Zmass = zfinder.bosons()[0].momentum().mass()/GeV;
61 double Zpt = zfinder.bosons()[0].momentum().pT()/GeV;
62 double Zpl = zfinder.bosons()[0].momentum().pz()/GeV;
63 double Zy = zfinder.bosons()[0].momentum().rapidity();
64 double ZE = zfinder.bosons()[0].momentum().E();
65
66 double xf = 2.*Zpl/sqrtS();
67 _h_xF_DiMuon->fill(xf);
68 _h_m_DiMuon->fill(Zmass/GeV);
69 _h_pT_DiMuon->fill(Zpt);
70 _h_y_DiMuon ->fill(Zy);
71
72 if (xf > -0.1 && xf < 0.2 && Zpt > 0) {
73 if (Zmass > 7. && Zmass < 8.) _hist_pT_M_78->fill(Zpt, 1./2./Zpt *2.*ZE/sqrtS());
74 if (Zmass > 8. && Zmass < 9.) _hist_pT_M_89->fill(Zpt, 1./2./Zpt *2.*ZE/sqrtS());
75 if (Zmass > 10.5 && Zmass < 11.5) _hist_pT_M_1011->fill(Zpt, 1./2./Zpt *2.*ZE/sqrtS());
76 if (Zmass > 11.5 && Zmass < 13.5) _hist_pT_M_1113->fill(Zpt, 1./2./Zpt *2.*ZE/sqrtS());
77 if (Zmass > 13.5 && Zmass < 18.) _hist_pT_M_1318->fill(Zpt, 1./2./Zpt *2.*ZE/sqrtS());
78 }
79 }
80
81 }
82
83
84 /// Normalise histograms etc., after the run
85 void finalize() {
86 MSG_DEBUG(" Generator cross section [pb] " << crossSection()/picobarn);
87
88 normalize(_h_m_DiMuon);
89 normalize(_h_pT_DiMuon);
90 normalize(_h_xF_DiMuon);
91 normalize(_h_y_DiMuon);
92
93 // normalisation of xF bin width = 0.3
94 const double scalefactor=crossSection()/picobarn/(sumOfWeights() * M_PI *0.3 );
95 scale(_hist_pT_M_78,scalefactor);
96 scale(_hist_pT_M_89,scalefactor);
97 scale(_hist_pT_M_1011,scalefactor);
98 scale(_hist_pT_M_1113,scalefactor);
99 scale(_hist_pT_M_1318,scalefactor);
100 }
101
102 //@}
103
104
105 /// @name Histograms
106 //@{
107 BinnedHistogram _hist_pT_M;
108 Histo1DPtr _h_m_DiMuon ;
109 Histo1DPtr _h_pT_DiMuon;
110 Histo1DPtr _h_y_DiMuon;
111 Histo1DPtr _h_xF_DiMuon;
112 Histo1DPtr _hist_pT_M_78,_hist_pT_M_89,_hist_pT_M_1011,_hist_pT_M_1113,_hist_pT_M_1318;
113 //@}
114
115 };
116
117
118 RIVET_DECLARE_PLUGIN(E605_1991_I302822);
119
120}
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