Rivet analyses referenceLHCB_2014_I1309880Mass distributions in $B_c^+\to J/\psi p\bar{p}\pi^+$Experiment: LHCB (LHC) Inspire ID: 1309880 Status: VALIDATED NOHEPDATA Authors:
Beam energies: ANY Run details:
Mass distributions in $B_c^+\to J/\psi p\bar{p}\pi^+$. The data were extracted from the plots in the paper and may not be corrected for efficiency and acceptance. Source code: LHCB_2014_I1309880.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_c -> J/psi p pbar pi+
10 class LHCB_2014_I1309880 : public Analysis {
11 public:
12
13 /// Constructor
14 RIVET_DEFAULT_ANALYSIS_CTOR(LHCB_2014_I1309880);
15
16
17 /// @name Analysis methods
18 /// @{
19
20 /// Book histograms and initialise projections before the run
21 void init() {
22 UnstableParticles ufs = UnstableParticles(Cuts::abspid==541);
23 declare(ufs, "UFS");
24 DecayedParticles BC(ufs);
25 BC.addStable( PID::PI0);
26 BC.addStable( PID::K0S);
27 BC.addStable( PID::JPSI);
28 declare(BC, "BC");
29 for(unsigned int ix=0;ix<2;++ix)
30 book(_h[ix],1,1,1+ix);
31 }
32
33
34 /// Perform the per-event analysis
35 void analyze(const Event& event) {
36 static const map<PdgId,unsigned int> & mode = { { 443,1}, { 2212,1}, { 2212,1}, { 211,1} };
37 static const map<PdgId,unsigned int> & modeCC = { { 443,1}, { 2212,1}, { 2212,1}, {-211,1} };
38 DecayedParticles BC = apply<DecayedParticles>(event, "BC");
39 // loop over particles
40 for(unsigned int ix=0;ix<BC.decaying().size();++ix) {
41 int sign = BC.decaying()[ix].pid()/BC.decaying()[ix].abspid();
42 if ((sign== 1 && BC.modeMatches(ix,4,mode )) ||
43 (sign==-1 && BC.modeMatches(ix,4,modeCC))) {
44 const Particle & prot = BC.decayProducts()[ix].at( sign*2212)[0];
45 const Particle & pbar = BC.decayProducts()[ix].at(-sign*2212)[0];
46 const Particle & pip = BC.decayProducts()[ix].at( sign*211 )[0];
47 _h[0]->fill((prot.momentum()+pbar.momentum()).mass());
48 _h[1]->fill((prot.momentum()+pip .momentum()).mass());
49 }
50 }
51 }
52
53
54 /// Normalise histograms etc., after the run
55 void finalize() {
56 for(unsigned int ix=0;ix<2;++ix)
57 normalize(_h[ix],1.,false);
58 }
59
60 /// @}
61
62
63 /// @name Histograms
64 /// @{
65 Histo1DPtr _h[2];
66 /// @}
67
68
69 };
70
71
72 RIVET_DECLARE_PLUGIN(LHCB_2014_I1309880);
73
74}
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