Rivet analyses
Measurement of R between 7.4 and 9.4 GeV
Experiment: LENA (DORIS)
Inspire ID: 179431
Status: VALIDATED
Authors: - Peter Richardson
References: - Z.Phys. C15 (1982) 299, 1982
Beams: e- e+
Beam energies: (3.7, 3.7); (3.7, 3.7); (3.7, 3.7); (3.7, 3.7); (3.7, 3.7); (3.7, 3.7); (3.7, 3.7); (3.7, 3.7); (3.7, 3.7); (3.7, 3.7); (3.7, 3.7); (3.7, 3.7); (3.7, 3.7); (3.7, 3.7); (4.3, 4.3); (4.3, 4.3); (4.3, 4.3); (4.3, 4.3); (4.4, 4.4); (4.4, 4.4); (4.4, 4.4); (4.4, 4.4); (4.4, 4.4); (4.4, 4.4); (4.4, 4.4); (4.4, 4.4); (4.4, 4.4); (4.4, 4.4); (4.4, 4.4); (4.4, 4.4); (4.4, 4.4); (4.4, 4.4); (4.4, 4.4); (4.4, 4.4); (4.4, 4.4); (4.4, 4.4); (4.4, 4.4); (4.4, 4.4); (4.4, 4.4); (4.4, 4.4); (4.4, 4.4); (4.4, 4.4); (4.5, 4.5); (4.5, 4.5); (4.5, 4.5); (4.5, 4.5); (4.5, 4.5); (4.5, 4.5); (4.5, 4.5); (4.5, 4.5); (4.5, 4.5); (4.5, 4.5); (4.5, 4.5); (4.5, 4.5); (4.5, 4.5); (4.5, 4.5); (4.5, 4.5); (4.5, 4.5); (4.5, 4.5); (4.6, 4.6); (4.6, 4.6); (4.6, 4.6); (4.6, 4.6); (4.6, 4.6); (4.6, 4.6); (4.6, 4.6); (4.6, 4.6); (4.6, 4.6); (4.6, 4.6); (4.6, 4.6); (4.6, 4.6); (4.6, 4.6); (4.6, 4.6); (4.6, 4.6); (4.6, 4.6); (4.6, 4.6); (4.6, 4.6); (4.6, 4.6); (4.6, 4.6); (4.7, 4.7); (4.7, 4.7); (4.7, 4.7); (4.7, 4.7); (4.7, 4.7); (4.7, 4.7); (4.7, 4.7); (4.7, 4.7); (4.7, 4.7); (4.7, 4.7); (4.7, 4.7); (4.7, 4.7)GeV
Run details: - e+ e- to hadrons and e+ e- to mu+ mu- (for normalization)
Measurement of R in e+e− collisions by LENA for energies between .4 and 9.4 GeV. The individual hadronic and muonic cross sections are also outputted to the yoda file so that ratio R can be recalculated if runs are combined.
Source
code:LENA_1982_I179431.cc
// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/FinalState.hh"
namespace Rivet {
/// @brief R measurement
class LENA_1982_I179431 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(LENA_1982_I179431);
/// @name Analysis methods
/// @{
/// Book histograms and initialise projections before the run
void init() {
// Initialise and register projections
declare(FinalState(), "FS");
// Book histograms
for (size_t i=0; i<2; ++i) {
const auto& ref = refData(i+1, 1, 1);
book(_h_hadrons[i], "d0"+to_string(i+1)+"_sigma_hadrons", ref);
book(_h_muons[i], "d0"+to_string(i+1)+"_sigma_muons", ref);
}
const auto& ref = refData<YODA::BinnedEstimate<string>>(3,1,1);
book(_c_hadrons, "d03_sigma_hadrons", ref);
book(_c_muons, "d03_sigma_muons", ref);
for (const string& en : _c_hadrons.binning().edges<0>()) {
double eval = stod(en);
if (isCompatibleWithSqrtS(eval)) {
_sqs = en; break;
}
}
raiseBeamErrorIf(_sqs.empty() && !inRange(sqrtS()/GeV, 7.4, 9.43));
}
/// Perform the per-event analysis
void analyze(const Event& event) {
const FinalState& fs = apply<FinalState>(event, "FS");
map<long,int> nCount;
int ntotal(0);
for (const Particle& p : fs.particles()) {
nCount[p.pid()] += 1;
++ntotal;
}
// mu+mu- + photons
if (nCount[-13]==1 and nCount[13]==1 && ntotal==2+nCount[22]) {
_h_muons[0]->fill(sqrtS()/GeV);
_h_muons[1]->fill(sqrtS()/GeV);
_c_muons->fill(_sqs);
}
// everything else
else {
_h_hadrons[0]->fill(sqrtS()/GeV);
_h_hadrons[1]->fill(sqrtS()/GeV);
_c_hadrons->fill(_sqs);
}
}
/// Normalise histograms etc., after the run
void finalize() {
scale({_c_hadrons, _c_muons}, crossSectionPerEvent());
scale(_h_hadrons, crossSectionPerEvent());
scale(_h_muons, crossSectionPerEvent());
for (size_t ix=0; ix<2; ++ix) {
Estimate1DPtr mult;
book(mult, ix+1, 1, 1);
divide(_h_hadrons[ix], _h_muons[ix], mult);
}
BinnedEstimatePtr<string> mult;
book(mult, 3, 1, 1);
divide(_c_hadrons,_c_muons,mult);
}
/// @}
/// @name Histograms
/// @{
BinnedHistoPtr<string> _c_hadrons, _c_muons;
Histo1DPtr _h_hadrons[2], _h_muons[2];
string _sqs = "";
/// @}
};
RIVET_DECLARE_PLUGIN(LENA_1982_I179431);
}