Rivet analyses

title: CLEOC_2005_I654529

Cross sections for exclusive hadronic processes in $e^+e^-$ collisions at $\sqrt{s}=3.67$

Experiment: CLEOC (CESR)

Inspire ID: 654529

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev.Lett. 94 (2005) 012005

Beams: e+ e-

Beam energies: (1.8, 1.8)GeV

Run details: - e+ e- > hadrons, pi0 and KS) set stable

Cross sections for $e^+e^-\to\pi^+\pi^-\pi^0$, $\rho\pi$, $\omega\pi$, $\phi\pi$, $\rho\eta$, $\omega\eta$, $K^{0}\bar{K}^0$ and $K^{+}K^-$ at $\sqrt{s}=3.67$

Source code:CLEOC_2005_I654529.cc

```c++ // -- C++ --

include "Rivet/Analysis.hh"

include "Rivet/Projections/FinalState.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief e+e- > hadrons at 3.67 class CLEOC_2005_I654529 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(CLEOC_2005_I654529);


/// @name Analysis methods
/// @{

/// Book histograms and initialise projections before the run
void init() {
  // projection
  declare(FinalState(), "FS");
  declare(UnstableParticles(), "UFS");
  // histos
  for (unsigned int ix = 0; ix < 14; ++ix) {
    book(_h[ix], 1, 1, 1 + ix);
  }
}

void findChildren(const Particle& p, map<long, int>& nRes, int& ncount) {
  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) {
  // final state particles
  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 == 3 && nCount[111] == 1 && nCount[211] == 1 && nCount[-211] == 1) {
    _h[0]->fill("3.67"s);
  }
  // unstable particles
  const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
  // first the omega, rho, phi  and b_10 pi0 final state
  bool matched = false;
  for (const Particle& p :
       ufs.particles(Cuts::pid == 113 || Cuts::pid == 223 || Cuts::pid == 333 || Cuts::pid == 10113)) {
    if (p.children().empty()) continue;
    map<long, int> nRes = nCount;
    int ncount = ntotal;
    findChildren(p, nRes, ncount);
    if (ncount == 1) {
      matched = true;
      for (const auto& val : nRes) {
        if (val.first == 111) {
          if (val.second != 1) {
            matched = false;
            break;
          }
        }
        else if (val.second != 0) {
          matched = false;
          break;
        }
      }
      if (matched) {
        if (p.pid() == 113) {
          _h[1]->fill("3.67"s);
          _h[2]->fill("3.67"s);
        }
        else if (p.pid() == 223)
          _h[4]->fill("3.67"s);
        else if (p.pid() == 333)
          _h[5]->fill("3.67"s);
        else if (p.pid() == 10113) {
          _h[11]->fill("3.67"s);
          _h[12]->fill("3.67"s);
        }
        break;
      }
    }
    else if (p.pid() != 10113) {
      // check for eta
      for (const Particle& p2 : ufs.particles(Cuts::pid == 221)) {
        map<long, int> nResB = nRes;
        int ncountB = ncount;
        findChildren(p2, nResB, ncountB);
        if (ncountB != 0) continue;
        matched = true;
        for (const auto& val : nResB) {
          if (val.second != 0) {
            matched = false;
            break;
          }
        }
        if (matched) {
          if (p.pid() == 113)
            _h[6]->fill("3.67"s);
          else if (p.pid() == 223)
            _h[7]->fill("3.67"s);
          else if (p.pid() == 333)
            _h[8]->fill("3.67"s);
          break;
        }
      }
    }
  }
  if (matched) return;
  // rho+- b1+- pi-+
  for (const Particle& p : ufs.particles(Cuts::abspid == 213 || Cuts::abspid == 10213)) {
    if (p.children().empty()) continue;
    map<long, int> nRes = nCount;
    int ncount = ntotal;
    findChildren(p, nRes, ncount);
    if (ncount != 1) continue;
    int sign = -p.pid() / p.abspid();
    matched = true;
    for (const auto& val : nRes) {
      if (val.first == sign * 211) {
        if (val.second != 1) {
          matched = false;
          break;
        }
      }
      else if (val.second != 0) {
        matched = false;
        break;
      }
    }
    if (matched) {
      if (p.abspid() == 213) {
        _h[1]->fill("3.67"s);
        _h[3]->fill("3.67"s);
      }
      else {
        _h[11]->fill("3.67"s);
        _h[13]->fill("3.67"s);
      }
      break;
    }
  }
  if (matched) return;
  // K* K
  for (const Particle& p : ufs.particles(Cuts::abspid == 313 || Cuts::abspid == 323)) {
    if (p.children().empty()) continue;
    map<long, int> nRes = nCount;
    int ncount = ntotal;
    findChildren(p, nRes, ncount);
    if (ncount != 1) continue;
    int iMeson = 0;
    int iStable = 0;
    for (const auto& val : nRes) {
      if (val.second == 1) {
        iStable += 1;
        iMeson = val.first;
      }
      else if (val.second != 0) {
        matched = false;
        break;
      }
    }
    if (iStable == 1) {
      if (p.abspid() == 313 || (iMeson == 310 || iMeson == 130)) {
        _h[9]->fill("3.67"s);
        break;
      }
      else if (p.abspid() == 323 and abs(iMeson) == 321 && p.pid() * iMeson < 0) {
        _h[10]->fill("3.67"s);
        break;
      }
      matched = false;
    }
    else {
      matched = false;
    }
  }
}


/// Normalise histograms etc., after the run
void finalize() {
  scale(_h, crossSection() / picobarn / sumOfWeights());
}

/// @}


/// @name Histograms
/// @{
BinnedHistoPtr<string> _h[14];
/// @}

};

RIVET_DECLARE_PLUGIN(CLEOC_2005_I654529); } ```