Rivet analyses referenceARGUS_1989_I267206$\bar{B}^0\to D^{*+}\ell^-\bar\nu_\ell$Experiment: ARGUS (DORIS) Inspire ID: 267206 Status: VALIDATED NOHEPDATA Authors:
Beam energies: ANY Run details:
$q^2$ spectrum, lepton momentum spectrum and $D^*$ helicty angle in $\bar{B}^0\to D^{*+}\ell^-\bar\nu_\ell$. Corrected data read from figure 7. Source code: ARGUS_1989_I267206.cc 1// -*- C++ -*-
2#include "Rivet/Analysis.hh"
3#include "Rivet/Projections/UnstableParticles.hh"
4#include "Rivet/Projections/DecayedParticles.hh"
5
6namespace Rivet {
7
8
9 /// @brief Bbar0 -> D* l nu
10 class ARGUS_1989_I267206 : public Analysis {
11 public:
12
13 /// Constructor
14 RIVET_DEFAULT_ANALYSIS_CTOR(ARGUS_1989_I267206);
15
16
17 /// @name Analysis methods
18 /// @{
19
20 /// Book histograms and initialise projections before the run
21 void init() {
22 // Initialise and register projections
23 UnstableParticles ufs = UnstableParticles(Cuts::abspid==511);
24 declare(ufs, "UFS");
25 DecayedParticles BB(ufs);
26 BB.addStable(411); BB.addStable(-411);
27 BB.addStable(421); BB.addStable(-421);
28 BB.addStable(413); BB.addStable(-413);
29 BB.addStable(423); BB.addStable(-423);
30 BB.addStable(PID::PI0);
31 declare(BB, "BB");
32 // histos
33 for (unsigned int ix=0; ix<3; ++ix) {
34 book(_h[ix], 1+ix, 1, 1);
35 }
36 }
37
38
39 /// Perform the per-event analysis
40 void analyze(const Event& event) {
41 // loop over B mesons
42 DecayedParticles BB = apply<DecayedParticles>(event, "BB");
43 // loop over particles
44 for (unsigned int ix=0; ix<BB.decaying().size(); ++ix) {
45 for (unsigned int il=0; il<2; ++il) {
46 if (BB.modeMatches(ix,3,mode[il])) {
47 int sign = il%2==0 ? -1 : 1;
48 const Particle & DD = BB.decayProducts()[ix].at(sign*413)[0];
49 const Particle & em = BB.decayProducts()[ix].at(sign*11)[0];
50 FourMomentum qq = BB.decaying()[ix].mom() - DD.mom();
51 _h[1]->fill(em.mom().p3().mod());
52 _h[2]->fill(qq.mass2());
53 if(DD.children().size()!=2) continue;
54 // boost to B rest frame
55 LorentzTransform boost1 = LorentzTransform::mkFrameTransformFromBeta(BB.decaying()[ix].mom().betaVec());
56 FourMomentum pDD = boost1.transform(DD.mom());
57 Particle D0;
58 if (DD.children()[0].pid() ==sign*211 && DD.children()[1].pid()==sign*421) {
59 D0 = DD.children()[1];
60 }
61 else if (DD.children()[1].pid()==sign*211 && DD.children()[0].pid()==sign*421) {
62 D0 = DD.children()[0];
63 }
64 else {
65 continue;
66 }
67 FourMomentum pD0 = boost1.transform(D0.mom());
68 LorentzTransform boost3 = LorentzTransform::mkFrameTransformFromBeta(pDD.betaVec());
69 pD0 = boost3.transform(pD0);
70 double cTheta = pD0.p3().unit().dot(pDD.p3().unit());
71 _h[0]->fill(cTheta);
72 }
73 }
74 }
75 }
76
77
78 /// Normalise histograms etc., after the run
79 void finalize() {
80 normalize(_h, 1.0, false);
81 }
82
83 /// @}
84
85
86 /// @name Histograms
87 /// @{
88 Histo1DPtr _h[3];
89 const map<PdgId,unsigned int> mode[2] = {{ {-413,1}, {-11,1}, { 12,1}}, { { 413,1}, { 11,1}, {-12,1}}};
90 /// @}
91
92
93 };
94
95
96 RIVET_DECLARE_PLUGIN(ARGUS_1989_I267206);
97
98}
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