Rivet analyses
Ratio of strange to non-strange B meson production at 7,8 and 13 TeV
Experiment: LHCB (LHC)
Inspire ID: 1760257
Status: VALIDATED NOHEPDATA
Authors: - Peter Richardson
References: - Phys.Rev.Lett. 124 (2020) 12, 122002
Beams: p+ p+
Beam energies: (3500.0, 3500.0); (4000.0, 4000.0); (6500.0, 6500.0)GeV
Run details: - b hadron production
Ratio of strange to non-strange B meson production at 7,8 and 13 TeV.
Source
code:LHCB_2019_I1760257.cc
// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"
namespace Rivet {
/// @brief strange fraction at 7,8,13 TeV
class LHCB_2019_I1760257 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(LHCB_2019_I1760257);
/// @name Analysis methods
/// @{
/// Book histograms and initialise projections before the run
void init() {
// projection
declare(UnstableParticles(), "UFS");
for (double eVal : allowedEnergies()) {
const int en(eVal+0.5);
if (isCompatibleWithSqrtS(eVal)) {
if (en == 7000) _sqs = 0;
else if (en == 8000) _sqs = 1;
else _sqs = 2;
}
}
raiseBeamErrorIf(_sqs < 0);
//histograms
for (size_t ix=0; ix<2; ++ix) {
book(_c_B[ix], "TMP/c_B_"+toString(ix+1), refData<YODA::BinnedEstimate<string> >(1,1,1));
for (size_t iy=0; iy<3; ++iy) {
book(_h_pT[ix][iy],"TMP/h_pT_"+toString(ix+1)+"_"+toString(iy+1), refData(5,1,1+iy));
book(_h_pL[ix][iy], "TMP/h_pL_"+toString(ix+1)+"_"+toString(iy+1), refData(3,1,1+iy));
}
for (size_t iy=0; iy<5; ++iy) {
book(_h_kin[ix][iy], "TMP/h_kin_"+toString(ix+1)+"_"+toString(iy+1), refData(4,1,1+iy));
}
}
}
/// Perform the per-event analysis
void analyze(const Event& event) {
if (_edges.empty()) _edges = _c_B[0]->xEdges();
for (const Particle& p : apply<UnstableParticles>(event, "UFS").particles(Cuts::abspid==521 or Cuts::abspid==531)) {
// kinematic region
// rapidity cuts
double y = p.rapidity(), eta = p.eta();
if (y<2. || y> 4.5 || eta<2. || eta>6.5) continue;
// momentum cuts
double pT = p.perp()/GeV, pL = p.momentum().z()/GeV, pTot=p.momentum().p3().mod()/GeV;
if (pT<0.5 || pT>40. || pTot<20. || pTot>700. || pL<20. || pL>700.) continue;
// type of meson
unsigned int imeson = (p.abspid()%100)/10 - 2;
_c_B [imeson]->fill(_edges[_sqs]);
if (_sqs==2) _c_B [imeson]->fill(_edges[3]);
_h_pT[imeson][_sqs]->fill(pT);
if (pL<75.) _h_pL[imeson][0]->fill(pT);
else if (pL<125.) _h_pL[imeson][1]->fill(pT);
else if (pL<700.) _h_pL[imeson][2]->fill(pT);
_h_kin[imeson][0]->fill(pTot);
_h_kin[imeson][1]->fill(pL );
_h_kin[imeson][2]->fill(pT );
_h_kin[imeson][3]->fill(eta );
_h_kin[imeson][4]->fill(y );
}
}
/// Normalise histograms etc., after the run
void finalize() {
// ratio of branching ratios from PDSG 2020
const double brRatio = 1.08e-3/1.02e-3;
for (size_t iy=0; iy<5; ++iy) {
Estimate1DPtr tmp;
book(tmp, 4, 1, iy+1);
divide(_h_kin[1][iy], _h_kin[0][iy], tmp);
tmp->scale(brRatio);
if (iy>=3) continue;
book(tmp, 3, 1, iy+1);
divide(_h_pL[1][iy], _h_pL[0][iy], tmp);
tmp->scale(brRatio);
book(tmp, 5, 1, 1+iy);
divide(_h_pT[1][iy], _h_pT[0][iy], tmp);
tmp->scale(brRatio);
}
// ratio
BinnedEstimatePtr<string> ratio;
book(ratio, 1, 1, 1);
divide(_c_B[1], _c_B[0], ratio);
ratio->scale(brRatio);
}
/// @}
/// @name Histograms
/// @{
int _sqs = -1;
vector<string> _edges;
BinnedHistoPtr<string> _c_B[2];
Histo1DPtr _h_pL[2][3],_h_kin[2][5], _h_pT[2][3];
/// @}
};
RIVET_DECLARE_PLUGIN(LHCB_2019_I1760257);
}