// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"
#include "Rivet/Projections/DecayedParticles.hh"
namespace Rivet {
/// @brief B0 -> p Lambdabar0 pi- and Bs0 -> p Lambdabar0 K-
class LHCB_2017_I1596893 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(LHCB_2017_I1596893);
/// @name Analysis methods
/// @{
/// Book histograms and initialise projections before the run
void init() {
// Initialise and register projections
UnstableParticles ufs = UnstableParticles(Cuts::abspid==511 or
Cuts::abspid==531);
declare(ufs, "UFS");
DecayedParticles B0(ufs);
B0.addStable( 3122);
B0.addStable(-3122);
declare(B0, "B0");
// book histograms
for(unsigned int ix=0;ix<2;++ix)
for(unsigned int iy=0;iy<3;++iy)
book(_h[ix][iy],1+ix,1,1+iy);
}
/// Perform the per-event analysis
void analyze(const Event& event) {
static const map<PdgId,unsigned int> & mode1 = { { 2212,1},{-3122,1}, {-211,1}};
static const map<PdgId,unsigned int> & mode1CC = { {-2212,1},{ 3122,1}, { 211,1}};
static const map<PdgId,unsigned int> & mode2 = { { 2212,1},{-3122,1}, {-321,1}};
static const map<PdgId,unsigned int> & mode2CC = { {-2212,1},{ 3122,1}, { 321,1}};
DecayedParticles B0 = apply<DecayedParticles>(event, "B0");
// loop over particles
for(unsigned int ix=0;ix<B0.decaying().size();++ix) {
int sign = 1, imode = 0;
if(B0.decaying()[ix].abspid()==511) {
if (B0.decaying()[ix].pid()>0 && B0.modeMatches(ix,3,mode1)) {
sign=1;
}
else if (B0.decaying()[ix].pid()<0 && B0.modeMatches(ix,3,mode1CC)) {
sign=-1;
}
else
continue;
imode=0;
}
else {
if (B0.decaying()[ix].pid()>0 && B0.modeMatches(ix,3,mode2)) {
sign=1;
}
else if (B0.decaying()[ix].pid()<0 && B0.modeMatches(ix,3,mode2CC)) {
sign=-1;
}
else
continue;
imode=1;
}
const Particle & pp = B0.decayProducts()[ix].at( sign*2212)[0];
const Particle & LamBar = B0.decayProducts()[ix].at(-sign*3122)[0];
const Particle & pim = B0.decayProducts()[ix].at(-sign*(imode==0 ? 211 : 321))[0];
_h[imode][0]->fill((pp .momentum()+LamBar.momentum()).mass());
_h[imode][1]->fill((pp .momentum()+pim .momentum()).mass());
_h[imode][2]->fill((pim.momentum()+LamBar.momentum()).mass());
}
}
/// Normalise histograms etc., after the run
void finalize() {
for(unsigned int ix=0;ix<2;++ix)
for(unsigned int iy=0;iy<3;++iy)
normalize(_h[ix][iy],1.,false);
}
/// @}
/// @name Histograms
/// @{
Histo1DPtr _h[2][3];
/// @}
};
RIVET_DECLARE_PLUGIN(LHCB_2017_I1596893);
}