Rivet analyses referenceBELLE_2015_I1392799Mass and angular distributions in $B^0\to p\bar{\Lambda}^0D^{(*)-}$Experiment: BELLE (KEKB) Inspire ID: 1392799 Status: VALIDATED NOHEPDATA Authors:
Beam energies: ANY Run details:
Measurement of the mass and angular distributions in $B^0\to p\bar{\Lambda}^0D^{(*)-}$. Data read from plots but is corrected for efficiency. Source code: BELLE_2015_I1392799.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 B -> p Lambda D
10 class BELLE_2015_I1392799 : public Analysis {
11 public:
12
13 /// Constructor
14 RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2015_I1392799);
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 B0(ufs);
26 B0.addStable( 411);
27 B0.addStable(-411);
28 B0.addStable( 413);
29 B0.addStable(-413);
30 B0.addStable(PID::LAMBDA);
31 B0.addStable(-PID::LAMBDA);
32 declare(B0, "B0");
33 //histograms
34 for(unsigned int ix=0;ix<2;++ix) {
35 for(unsigned int iy=0;iy<2;++iy) {
36 book(_h[ix][iy],1+ix,1,1+iy);
37 }
38 }
39 book(_nB,"/TMP/nb");
40 }
41
42
43 /// Perform the per-event analysis
44 void analyze(const Event& event) {
45 static const map<PdgId,unsigned int> & mode1 = { { 2212,1},{-3122,1}, {-411,1}};
46 static const map<PdgId,unsigned int> & mode1CC = { {-2212,1},{ 3122,1}, { 411,1}};
47 static const map<PdgId,unsigned int> & mode2 = { { 2212,1},{-3122,1}, {-413,1}};
48 static const map<PdgId,unsigned int> & mode2CC = { {-2212,1},{ 3122,1}, { 413,1}};
49 DecayedParticles B0 = apply<DecayedParticles>(event, "B0");
50 // loop over particles
51 for(unsigned int ix=0;ix<B0.decaying().size();++ix) {
52 _nB->fill();
53 int sign = 1, imode = 0;
54 if (B0.decaying()[ix].pid()>0 && B0.modeMatches(ix,3,mode1)) {
55 imode=0;
56 sign=1;
57 }
58 else if (B0.decaying()[ix].pid()<0 && B0.modeMatches(ix,3,mode1CC)) {
59 imode=0;
60 sign=-1;
61 }
62 else if (B0.decaying()[ix].pid()>0 && B0.modeMatches(ix,3,mode2)) {
63 imode=1;
64 sign=1;
65 }
66 else if (B0.decaying()[ix].pid()<0 && B0.modeMatches(ix,3,mode2CC)) {
67 imode=1;
68 sign=-1;
69 }
70 else
71 continue;
72 int iD = imode==0 ? 411 : 413;
73 const Particle & pp = B0.decayProducts()[ix].at( sign*2212)[0];
74 const Particle & lam = B0.decayProducts()[ix].at(-sign*3122)[0];
75 const Particle & Dm = B0.decayProducts()[ix].at(-sign*iD )[0];
76 _h[0][imode]->fill((lam.momentum()+pp.momentum()).mass());
77 // first boost to B rest frame
78 LorentzTransform boostB = LorentzTransform::mkFrameTransformFromBeta(B0.decaying()[ix].momentum().betaVec());
79 FourMomentum ppp = boostB.transform(pp .momentum());
80 FourMomentum plam = boostB.transform(lam.momentum());
81 FourMomentum pDm = boostB.transform(Dm .momentum());
82 LorentzTransform boostpLam = LorentzTransform::mkFrameTransformFromBeta((ppp+plam).betaVec());
83 ppp = boostpLam.transform(ppp);
84 pDm = boostpLam.transform(pDm);
85 _h[1][imode]->fill(ppp.p3().unit().dot(pDm.p3().unit()));
86 }
87 }
88
89
90 /// Normalise histograms etc., after the run
91 void finalize() {
92 for(unsigned int ix=0;ix<2;++ix) {
93 double fact = ix==0 ? 1e3 : 1e6;
94 for(unsigned int iy=0;iy<2;++iy) {
95 scale(_h[ix][iy], fact/ *_nB);
96 }
97 }
98 }
99
100 /// @}
101
102
103 /// @name Histograms
104 /// @{
105 Histo1DPtr _h[2][2];
106 CounterPtr _nB;
107 /// @}
108
109
110 };
111
112
113 RIVET_DECLARE_PLUGIN(BELLE_2015_I1392799);
114
115}
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