Rivet analyses
γγ → K*0K̄*0 and K*+K*− between 1.5 and 3.0 GeV
Experiment: ARGUS (DORIS)
Inspire ID: 511512
Status: VALIDATED
Authors: - Peter Richardson
References: - Eur.Phys.J.C 16 (2000) 435-444
Beams: 22 22
Beam energies: ANY
Run details: - gamma gamma to hadrons, K0S and pi0 mesons must be set stable
Measurement of the differential cross section for γγ → K*0K̄*0 andK*+K*− for 1.5GeV < W < 3.0GeV. The cross section is measured as a function of the centre-of-mass energy of the photonic collision using a range of final states.
Source
code:ARGUS_2000_I511512.cc
// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/FinalState.hh"
#include "Rivet/Projections/UnstableParticles.hh"
namespace Rivet {
/// @brief gamma gamma -> K*K*
class ARGUS_2000_I511512 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(ARGUS_2000_I511512);
/// @name Analysis methods
/// @{
/// Book histograms and initialise projections before the run
void init() {
// Initialise and register projections
declare(FinalState(), "FS");
declare(UnstableParticles(), "UFS");
// book histos
raiseBeamErrorIf(!inRange(sqrtS() / GeV, 1.5, 3.0));
// loop over tables in paper
book(_h["K0K0_5"], 3, 1, 1);
book(_h["K0K0_3"], 4, 1, 1);
book(_h["K0K0_1"], 5, 1, 1);
book(_h["K0K0_KSKSpp"], 9, 1, 1);
book(_h["K0K0_KSK+pp"], 6, 1, 2);
book(_h["K0K0"], 10, 1, 1);
book(_h["KpKm_KSK+pp"], 6, 1, 1);
book(_h["KpKm_KSKSpp"], 8, 1, 1);
book(_h["KpKm_K+K-pp"], 9, 1, 2);
book(_h["K+K-"], 10, 1, 2);
book(_h["rhoPi_5"], 3, 1, 3);
book(_h["rhoPi_3"], 4, 1, 3);
book(_h["rhoPi_1"], 5, 1, 3);
book(_h["K0K+-_5"], 3, 1, 2);
book(_h["K0K+-_3"], 4, 1, 2);
book(_h["K0K+-_1"], 5, 1, 2);
book(_h["K+KS-l-"], 7, 1, 1);
book(_h["K+KS-p-"], 8, 1, 2);
book(_h["K+K-p0"], 7, 1, 2);
book(_h["KSKSp-p0"], 7, 1, 3);
book(_h["KSKSp+p-"], 8, 1, 3);
book(_h["K+K-p+p-_5"], 3, 1, 4);
book(_h["K+K-p+p-_3"], 4, 1, 4);
book(_h["K+K-p+p-_1"], 5, 1, 4);
book(_h["num"], "TMP/nMeson_num", refData(11, 1, 1));
book(_h["den"], "TMP/nMeson_den", refData(11, 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()] -= 1;
--ncount;
}
else {
findChildren(child, nRes, ncount);
}
}
}
/// Perform the per-event analysis
void analyze(const Event& event) {
const FinalState& fs = apply<FinalState>(event, "FS");
// find the final-state particles
map<long, int> nCount;
int ntotal(0);
for (const Particle& p : fs.particles()) {
nCount[p.pid()] += 1;
++ntotal;
}
if (ntotal == 4) {
if (nCount[PID::KPLUS] == 1 && nCount[PID::KMINUS] == 1 && nCount[PID::PIPLUS] == 1
&& nCount[PID::PIMINUS] == 1) {
_h["K+K-p+p-_5"]->fill(sqrtS() / GeV);
_h["K+K-p+p-_3"]->fill(sqrtS() / GeV);
_h["K+K-p+p-_1"]->fill(sqrtS() / GeV);
}
else if (nCount[PID::K0S] == 2 && nCount[PID::PIPLUS] == 1 && nCount[PID::PIMINUS] == 1) {
_h["KSKSp+p-"]->fill(sqrtS() / GeV);
}
else if (nCount[PID::K0S] == 1 && nCount[PID::PI0] == 1
&& ((nCount[PID::KPLUS] == 1 && nCount[PID::PIMINUS] == 1)
|| (nCount[PID::KMINUS] == 1 && nCount[PID::PIPLUS] == 1))) {
_h["KSKSp-p0"]->fill(sqrtS() / GeV);
}
}
const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
// find any K* mesons
Particles Kstar = ufs.particles(Cuts::abspid == 313 or Cuts::abspid == 323);
for (size_t ix = 0; ix < Kstar.size(); ++ix) {
if (Kstar[ix].children().empty()) continue;
map<long, int> nRes = nCount;
int ncount = ntotal;
findChildren(Kstar[ix], nRes, ncount);
int sign = Kstar[ix].pid() / Kstar[ix].abspid();
// three body intermediate states
if (ncount == 2) {
// K*0 K- pi+ +ccd
if (Kstar[ix].abspid() == 313) {
bool matched = true;
for (const auto& val : nRes) {
if (val.first == sign * 211 || val.first == -sign * 321) {
if (val.second != 1) {
matched = false;
break;
}
}
else {
if (val.second != 0) {
matched = false;
break;
}
}
}
if (matched) {
_h["K0K+-_5"]->fill(sqrtS() / GeV);
_h["K0K+-_3"]->fill(sqrtS() / GeV);
_h["K0K+-_1"]->fill(sqrtS() / GeV);
}
}
else {
bool matched = false;
// K*+ K0S pi- + cc
for (const auto& val : nRes) {
if (val.first == -sign * 211 || val.first == PID::K0S) {
if (val.second != 1) {
matched = false;
break;
}
}
else {
if (val.second != 0) {
matched = false;
break;
}
}
}
if (matched) {
_h["K+KS-l-"]->fill(sqrtS() / GeV);
_h["K+KS-p-"]->fill(sqrtS() / GeV);
}
else {
// K*+ K- pi0 +cc
matched = false;
for (const auto& val : nRes) {
if (val.first == -sign * 321 || val.first == PID::PI0) {
if (val.second != 1) {
matched = false;
break;
}
}
else {
if (val.second != 0) {
matched = false;
break;
}
}
}
if (matched) _h["K+K-p0"]->fill(sqrtS() / GeV);
}
}
}
// K*K*
for (size_t iy = ix + 1; iy < Kstar.size(); ++iy) {
if (Kstar[iy].children().empty()) continue;
if (Kstar[ix].pid() != -Kstar[iy].pid()) continue;
map<long, int> nRes2 = nRes;
int ncount2 = ncount;
findChildren(Kstar[iy], nRes2, ncount2);
if (ncount2 != 0) continue;
bool matched2 = true;
for (const auto& val : nRes2) {
if (val.second != 0) {
matched2 = false;
break;
}
}
if (matched2) {
if (Kstar[ix].abspid() == 313) {
_h["K0K0_5"]->fill(sqrtS() / GeV);
_h["K0K0_3"]->fill(sqrtS() / GeV);
_h["K0K0_1"]->fill(sqrtS() / GeV);
_h["K0K0_KSKSpp"]->fill(sqrtS() / GeV);
_h["K0K0_KSK+pp"]->fill(sqrtS() / GeV);
_h["K0K0"]->fill(sqrtS() / GeV);
_h["den"]->fill(sqrtS() / GeV);
}
else {
_h["KpKm_KSK+pp"]->fill(sqrtS() / GeV);
_h["KpKm_KSKSpp"]->fill(sqrtS() / GeV);
_h["KpKm_K+K-pp"]->fill(sqrtS() / GeV);
_h["K+K-"]->fill(sqrtS() / GeV);
_h["num"]->fill(sqrtS() / GeV);
}
break;
}
}
}
// finally the rho phi intermediate states
for (const Particle& p1 : ufs.particles(Cuts::pid == PID::RHO0)) {
if (p1.children().empty()) continue;
map<long, int> nRes = nCount;
int ncount = ntotal;
findChildren(p1, nRes, ncount);
for (const Particle& p2 : ufs.particles(Cuts::pid == PID::PHI)) {
if (p2.children().empty()) continue;
map<long, int> nRes2 = nRes;
int ncount2 = ncount;
findChildren(p2, nRes2, ncount2);
if (ncount2 != 0) continue;
bool matched = true;
for (const auto& val : nRes2) {
if (val.second != 0) {
matched = false;
break;
}
}
if (matched) {
_h["rhoPi_5"]->fill(sqrtS() / GeV);
_h["rhoPi_3"]->fill(sqrtS() / GeV);
_h["rhoPi_1"]->fill(sqrtS() / GeV);
break;
}
}
}
}
/// Normalise histograms etc., after the run
void finalize() {
scale(_h, crossSection() / nanobarn / sumOfWeights());
// finally the ratio K*+/K*0
Estimate1DPtr mult;
book(mult, 11, 1, 1);
divide(_h["num"], _h["den"], mult);
}
/// @}
/// @name Histograms
/// @{
map<string, Histo1DPtr> _h;
/// @}
};
RIVET_DECLARE_PLUGIN(ARGUS_2000_I511512);
}