Rivet analyses
Cross sections for e+e−→ exclusive hadronic states between 0.5 and 1.4 GeV.
Experiment: ND (VEPP-2M)
Inspire ID: 321108
Status: VALIDATED
Authors: - Peter Richardson
References: - PRep 202,99
Beams: e+ e-
Beam energies: (0.3, 0.3); (0.3, 0.3); (0.3, 0.3); (0.3, 0.3); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.4, 0.4); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.6, 0.6); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.8, 0.8); (0.8, 0.8)GeV
Run details: - e+ e- to hadrons
Measurement of the cross section for e+e− → π+π−, K+K−, KS0KL0, π+π−π0, 2π+2π−, π+π−2π0, ωπ0, ηπ+π− and 2π+2π−π0 by ND for energies between 0.5 and 1.4 GeV.
Source
code:ND_1991_I321108.cc
// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/FinalState.hh"
#include "Rivet/Projections/UnstableParticles.hh"
namespace Rivet {
/// @brief ND measurement of exclusive hadronic final states
class ND_1991_I321108 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(ND_1991_I321108);
/// @name Analysis methods
/// @{
/// Book histograms and initialise projections before the run
void init() {
// Initialise and register projections
declare(FinalState(), "FS");
declare(UnstableParticles(), "UFS");
// book hists
vector<string> energies(
{"0.661", "0.671", "0.681", "0.691", "0.701", "0.711", "0.725", "0.735", "0.745", "0.755", "0.765",
"0.805", "0.81", "0.815", "0.825", "0.83", "0.831", "0.841", "0.85", "0.851", "0.861", "0.87",
"0.871", "0.881", "0.89", "0.891", "0.901", "0.91", "0.911", "0.921", "0.93", "0.943", "0.95",
"0.955", "0.956", "0.963", "0.97", "0.973", "0.98", "0.983", "0.99", "0.993", "1.0", "1.003",
"1.005", "1.02", "1.036", "1.04", "1.05", "1.059", "1.06", "1.07", "1.075", "1.08", "1.09",
"1.099", "1.1", "1.11", "1.12", "1.13", "1.139", "1.14", "1.15", "1.16", "1.17", "1.179",
"1.18", "1.19", "1.2", "1.21", "1.219", "1.22", "1.23", "1.24", "1.25", "1.259", "1.26",
"1.27", "1.28", "1.29", "1.299", "1.3", "1.31", "1.32", "1.325", "1.33", "1.339", "1.34",
"1.35", "1.36", "1.37", "1.375", "1.379", "1.38", "1.39", "1.395", "1.4", "1.5", "1.6"});
for (const string& en : energies) {
if (isCompatibleWithSqrtS(stod(en) * GeV)) {
_sqs = en;
break;
}
}
raiseBeamErrorIf(_sqs.empty());
book(_h["nOmegaPi0"], 1, 1, 1);
book(_h["nOmegaPi1"], 2, 1, 1);
book(_h["nOmegaPi2"], 3, 1, 1);
book(_h["nOmegaPi3"], 4, 1, 1);
book(_h["nOmegaPi4"], 10, 1, 3);
book(_h["n2Pi"], 11, 1, 1);
book(_h["n3Pi0"], 5, 1, 1);
book(_h["n3Pi1"], 10, 1, 4);
book(_h["n4PiC0"], 7, 1, 1);
book(_h["n4PiC1"], 10, 1, 1);
book(_h["n4PiN0"], 8, 1, 1);
book(_h["n4PiN1"], 10, 1, 2);
book(_h["nEtaPiPi"], 6, 1, 1);
book(_h["nKC"], 12, 1, 1);
book(_h["nKN"], 13, 1, 1);
book(_h["n5Pi"], 14, 1, 1);
}
void findChildren(const Particle& p, map<long, int>& nRes, int& ncount) const {
for (const Particle& child : p.children()) {
if (child.children().empty()) {
--nRes[child.pid()];
--ncount;
}
else
findChildren(child, nRes, ncount);
}
}
/// 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;
}
if (ntotal == 2) {
if (nCount[211] == 1 && nCount[-211] == 1) _h["n2Pi"]->fill(_sqs);
if (nCount[321] == 1 && nCount[-321] == 1) _h["nKC"]->fill(_sqs);
if (nCount[310] == 1 && nCount[130] == 1) _h["nKN"]->fill(_sqs);
}
else if (ntotal == 3) {
if (nCount[211] == 1 && nCount[-211] == 1 && nCount[111] == 1) {
_h["n3Pi0"]->fill(_sqs);
_h["n3Pi1"]->fill(_sqs);
}
}
else if (ntotal == 4) {
if (nCount[211] == 2 && nCount[-211] == 2) {
_h["n4PiC0"]->fill(_sqs);
_h["n4PiC1"]->fill(_sqs);
}
else if (nCount[211] == 1 && nCount[-211] == 1 && nCount[111] == 2) {
_h["n4PiN0"]->fill(_sqs);
_h["n4PiN1"]->fill(_sqs);
}
}
else if (ntotal == 5) {
if (nCount[211] == 2 && nCount[-211] == 2 && nCount[111] == 1) _h["n5Pi"]->fill(_sqs);
}
const FinalState& ufs = apply<FinalState>(event, "UFS");
for (const Particle& p : ufs.particles()) {
if (p.children().empty()) continue;
// find the eta
if (p.pid() == 221) {
map<long, int> nRes = nCount;
int ncount = ntotal;
findChildren(p, nRes, ncount);
// eta pi+pi-
if (ncount != 2) continue;
bool matched = true;
for (const auto& val : nRes) {
if (abs(val.first) == 211) {
if (val.second != 1) {
matched = false;
break;
}
}
else if (val.second != 0) {
matched = false;
break;
}
}
if (matched) _h["nEtaPiPi"]->fill(_sqs);
}
else if (p.pid() == 223) {
map<long, int> nRes = nCount;
int ncount = ntotal;
findChildren(p, nRes, ncount);
// eta pi+pi-
if (ncount != 1) continue;
bool matched = true;
for (const auto& val : nRes) {
if (abs(val.first) == 111) {
if (val.second != 1) {
matched = false;
break;
}
}
else if (val.second != 0) {
matched = false;
break;
}
}
if (matched) {
_h["nOmegaPi0"]->fill(_sqs);
_h["nOmegaPi1"]->fill(_sqs);
_h["nOmegaPi2"]->fill(_sqs);
_h["nOmegaPi3"]->fill(_sqs);
_h["nOmegaPi4"]->fill(_sqs);
}
}
}
}
/// Normalise histograms etc., after the run
void finalize() {
scale(_h, crossSection() / sumOfWeights() / nanobarn);
}
/// @}
/// @name Histograms
/// @{
map<string, BinnedHistoPtr<string>> _h;
string _sqs = "";
/// @}
};
RIVET_DECLARE_PLUGIN(ND_1991_I321108);
}