Rivet analyses referenceCLEO_2013_I1081165Kinematic distributions in $D^0\to \pi^-\pi^0 e^+\nu_e$ and $D^+\to \pi^+\pi^- e^+\nu_e$Experiment: CLEO (CESR) Inspire ID: 1081165 Status: VALIDATED NOHEPDATA Authors:
Beam energies: ANY Run details:
Measurement of the kinematic distributions in $D^0\to \pi^-\pi^0 e^+\nu_e$ and $D^+\to \pi^+\pi^- e^+\nu_e$ by CLEO. N.B. the plots where read from the paper and may not have been corrected for acceptance. Source code: CLEO_2013_I1081165.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 D -> rho e nu
10 class CLEO_2013_I1081165 : public Analysis {
11 public:
12
13 /// Constructor
14 RIVET_DEFAULT_ANALYSIS_CTOR(CLEO_2013_I1081165);
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::pid==411 ||Cuts::pid==421);
24 declare(ufs, "UFS");
25 DecayedParticles DD(ufs);
26 DD.addStable(PID::PI0);
27 DD.addStable(PID::K0S);
28 DD.addStable(PID::ETA);
29 DD.addStable(PID::ETAPRIME);
30 declare(DD, "DD");
31
32 // Book histograms
33 for(unsigned int ix=0;ix<4;++ix)
34 book(_h[ix],1,1,1+ix);
35 }
36
37
38 /// Perform the per-event analysis
39 void analyze(const Event& event) {
40 static const map<PdgId,unsigned int> & mode1 = { { 111,1}, {-211,1}, {-11,1}, { 12,1}};
41 static const map<PdgId,unsigned int> & mode2 = { { 211,1}, {-211,1}, {-11,1}, { 12,1}};
42 DecayedParticles DD = apply<DecayedParticles>(event, "DD");
43 // loop over particles
44 for(unsigned int ix=0;ix<DD.decaying().size();++ix) {
45 Particle pi2;
46 if (DD.decaying()[ix].pid()==421 && DD.modeMatches(ix,4,mode1)) {
47 pi2= DD.decayProducts()[ix].at(111)[0];
48 }
49 else if(DD.decaying()[ix].pid()==411 && DD.modeMatches(ix,4,mode2)) {
50 pi2= DD.decayProducts()[ix].at(211)[0];
51 }
52 else continue;
53 const Particle & pim= DD.decayProducts()[ix].at(-211)[0];
54 const Particle & ep = DD.decayProducts()[ix].at(-11)[0];
55 const Particle & nue= DD.decayProducts()[ix].at( 12)[0];
56 FourMomentum pRho = pi2.momentum()+pim.momentum();
57 if(abs(pRho.mass()-0.7753)>0.15) continue;
58 FourMomentum qq = DD.decaying()[ix].momentum()-pRho;
59 _h[0]->fill(qq.mass2());
60 // boost momenta to D rest frame
61 LorentzTransform boost = LorentzTransform::mkFrameTransformFromBeta(DD.decaying()[ix].momentum().betaVec());
62 FourMomentum pPP = boost.transform(pRho);
63 Matrix3 ptoz(-pPP.p3().unit(), Vector3(0,0,1));
64 boost.preMult(ptoz);
65 // the momenta in frane to W along z
66 FourMomentum pD = boost.transform(DD.decaying()[ix].momentum());
67 FourMomentum ppi2 = boost.transform(pi2.momentum());
68 FourMomentum ppim = boost.transform(pim.momentum());
69 FourMomentum pe = boost.transform(ep .momentum());
70 FourMomentum pnu = boost.transform(nue.momentum());
71 pRho = ppi2+ppim;
72 qq = pD-pRho;
73 LorentzTransform boostRho = LorentzTransform::mkFrameTransformFromBeta(pRho.betaVec());
74 Vector3 axisRho = boostRho.transform(ppim).p3().unit();
75 _h[1]->fill(axisRho.dot(pRho.p3().unit()));
76 LorentzTransform boostW = LorentzTransform::mkFrameTransformFromBeta( qq.betaVec());
77 Vector3 axisE = boostW.transform(pe).p3().unit();
78 _h[2]->fill(axisE.dot(qq.p3().unit()));
79 axisRho.setZ(0.);
80 axisE.setZ(0.);
81 double chi = atan2(axisE.cross(axisRho).dot(qq.p3().unit()), axisE.dot(axisRho));
82 _h[3]->fill(chi);
83 }
84 }
85
86
87 /// Normalise histograms etc., after the run
88 void finalize() {
89 for(unsigned int ix=0;ix<4;++ix)
90 normalize(_h[ix]);
91 }
92
93 /// @}
94
95
96 /// @name Histograms
97 /// @{
98 Histo1DPtr _h[4];
99 /// @}
100
101
102 };
103
104
105 RIVET_DECLARE_PLUGIN(CLEO_2013_I1081165);
106
107}
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