Rivet analyses
Measurements of Semi-Leptonic Tau Decays into Three Charged Hadrons
Experiment: BaBar (PEP-II)
Inspire ID: 756323
Status: VALIDATED
Authors: - Peter Richardson
References: - Phys.Rev.Lett.100:011801,2008 - arXiv: 0707.2981 - SLAC-R-936
Beams: * *
Beam energies: ANY
Run details: - Tau production, can be any process but original data was in e+e− at the Υ(4S) resonance, with CoM boosts of 8.0 GeV~(e−) and 3.5GeV(e+)
Measurement of tau decays to three charged hadrons using a data sample corresponding to an integrated luminosity of 342 fb−1 collected with the BABAR detector at the SLAC PEP-II electron-positron storage ring operating at a center-of-mass energy near 10.58 GeV. Can be run with any process producing tau leptons.’
Source
code:BABAR_2007_I756323.cc
// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"
namespace Rivet {
/// @brief BABAR tau lepton to three charged hadrons
///
/// @author Peter Richardson
class BABAR_2007_I756323 : public Analysis {
public:
RIVET_DEFAULT_ANALYSIS_CTOR(BABAR_2007_I756323);
void init() {
declare(UnstableParticles(), "UFS");
book(_hist_pipipi_pipipi , 1, 1, 1);
book(_hist_pipipi_pipi , 2, 1, 1);
book(_hist_Kpipi_Kpipi , 3, 1, 1);
book(_hist_Kpipi_Kpi , 4, 1, 1);
book(_hist_Kpipi_pipi , 5, 1, 1);
book(_hist_KpiK_KpiK , 6, 1, 1);
book(_hist_KpiK_KK , 7, 1, 1);
book(_hist_KpiK_piK , 8, 1, 1);
book(_hist_KKK_KKK , 9, 1, 1);
book(_hist_KKK_KK ,10, 1, 1);
book(_weight_total, "/TMP/weight_total");
book(_weight_pipipi, "/TMP/weight_pipipi");
book(_weight_Kpipi, "/TMP/weight_Kpipi");
book(_weight_KpiK, "/TMP/weight_KpiK");
book(_weight_KKK, "/TMP/weight_KKK");
}
void analyze(const Event& e) {
// Find the taus
Particles taus;
for(const Particle& p : apply<UnstableParticles>(e, "UFS").particles(Cuts::pid==PID::TAU)) {
_weight_total->fill();
Particles pip, pim, Kp, Km;
unsigned int nstable = 0;
// Find the decay products we want
findDecayProducts(p, nstable, pip, pim, Kp, Km);
if (p.pid() < 0) {
swap(pip, pim);
swap(Kp, Km );
}
if (nstable != 4) continue;
// pipipi
if (pim.size() == 2 && pip.size() == 1) {
_weight_pipipi->fill();
_hist_pipipi_pipipi->
fill((pip[0].momentum()+pim[0].momentum()+pim[1].momentum()).mass());
_hist_pipipi_pipi->
fill((pip[0].momentum()+pim[0].momentum()).mass());
_hist_pipipi_pipi->
fill((pip[0].momentum()+pim[1].momentum()).mass());
}
else if (pim.size() == 1 && pip.size() == 1 && Km.size() == 1) {
_weight_Kpipi->fill();
_hist_Kpipi_Kpipi->
fill((pim[0].momentum()+pip[0].momentum()+Km[0].momentum()).mass());
_hist_Kpipi_Kpi->
fill((pip[0].momentum()+Km[0].momentum()).mass());
_hist_Kpipi_pipi->
fill((pim[0].momentum()+pip[0].momentum()).mass());
}
else if (Kp.size() == 1 && Km.size() == 1 && pim.size() == 1) {
_weight_KpiK->fill();
_hist_KpiK_KpiK->
fill((Kp[0].momentum()+Km[0].momentum()+pim[0].momentum()).mass());
_hist_KpiK_KK->
fill((Kp[0].momentum()+Km[0].momentum()).mass());
_hist_KpiK_piK->
fill((Kp[0].momentum()+pim[0].momentum()).mass());
}
else if (Kp.size() == 1 && Km.size() == 2) {
_weight_KKK->fill();
_hist_KKK_KKK->
fill((Kp[0].momentum()+Km[0].momentum()+Km[1].momentum()).mass());
_hist_KKK_KK->
fill((Kp[0].momentum()+Km[0].momentum()).mass());
_hist_KKK_KK->
fill((Kp[0].momentum()+Km[1].momentum()).mass());
}
}
}
void finalize() {
normalize(_hist_pipipi_pipipi);
normalize(_hist_pipipi_pipi);
normalize(_hist_Kpipi_Kpipi);
normalize(_hist_Kpipi_Kpi );
normalize(_hist_Kpipi_pipi );
normalize(_hist_KpiK_KpiK );
normalize(_hist_KpiK_KK );
normalize(_hist_KpiK_piK );
normalize(_hist_KKK_KKK );
normalize(_hist_KKK_KK );
Estimate0DPtr tmp;
book(tmp,11,1,1);
divide(*_weight_pipipi, *_weight_total, tmp);
scale(tmp,100.);
book(tmp,12,1,1);
divide(*_weight_Kpipi, *_weight_total, tmp);
scale(tmp,100.);
book(tmp,13,1,1);
divide(*_weight_KpiK, *_weight_total, tmp);
scale(tmp,100.);
book(tmp,14,1,1);
divide(*_weight_KKK, *_weight_total, tmp);
scale(tmp,100.);
}
private:
// Histograms
Histo1DPtr _hist_pipipi_pipipi, _hist_pipipi_pipi;
Histo1DPtr _hist_Kpipi_Kpipi, _hist_Kpipi_Kpi, _hist_Kpipi_pipi;
Histo1DPtr _hist_KpiK_KpiK, _hist_KpiK_KK, _hist_KpiK_piK;
Histo1DPtr _hist_KKK_KKK, _hist_KKK_KK;
// Weights counters
CounterPtr _weight_total, _weight_pipipi, _weight_Kpipi, _weight_KpiK, _weight_KKK;
void findDecayProducts(const Particle &mother,
unsigned int & nstable,
Particles& pip, Particles& pim,
Particles& Kp, Particles& Km) {
for (const Particle &p : mother.children()) {
long id = p.pid();
if (id == PID::PI0 )
++nstable;
else if (id == PID::K0S)
++nstable;
else if (id == PID::PIPLUS) {
pip.push_back(p);
++nstable;
}
else if (id == PID::PIMINUS) {
pim.push_back(p);
++nstable;
}
else if (id == PID::KPLUS) {
Kp.push_back(p);
++nstable;
}
else if (id == PID::KMINUS) {
Km.push_back(p);
++nstable;
}
else if (!p.children().empty()) {
findDecayProducts(p, nstable, pip, pim, Kp, Km);
}
else ++nstable;
}
}
};
RIVET_DECLARE_ALIASED_PLUGIN(BABAR_2007_I756323, BABAR_2007_S7266081);
}Aliases: - BABAR_2007_S7266081