Rivet analyses
Mass and angular distributions in B0 → K+π−(J/ψ, ψ(2S)) and B+ → KS0π+(J/ψ, ψ(2S))
Experiment: BABAR (PEP-II)
Inspire ID: 801589
Status: VALIDATED NOHEPDATA
Authors: - Peter Richardson
References: - Phys.Rev.D 79 (2009) 112001
Beams: * *
Beam energies: ANY
Run details: - Any process producing B+ and B0 mesons, originally Upsilon(4S) decays
Mass and angular distributions in B0 → K+π−(J/ψ, ψ(2S)) and B+ → KS0π+(J/ψ, ψ(2S)). The corrected, background subtracted data was read from the figures in the paper.
Source
code:BABAR_2009_I801589.cc
// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/DecayedParticles.hh"
#include "Rivet/Projections/UnstableParticles.hh"
namespace Rivet {
/// @brief B -> J/psi / psi(2S) K pi
class BABAR_2009_I801589 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BABAR_2009_I801589);
/// @name Analysis methods
/// @{
/// Book histograms and initialise projections before the run
void init() {
// Initialise and register projections
UnstableParticles ufs = UnstableParticles(Cuts::abspid == 511 || Cuts::abspid == 521);
declare(ufs, "UFS");
DecayedParticles BB(ufs);
BB.addStable(310);
BB.addStable(443);
BB.addStable(100443);
declare(BB, "BB");
// histos
for (unsigned int ix = 0; ix < 2; ++ix) {
book(_h_Kpi2[ix], 2, 1, 1 + ix);
book(_h_angle[ix], 4, 1, 1 + ix);
book(_c[ix], "TMP/c_" + toString(ix));
for (unsigned int iy = 0; iy < 2; ++iy) {
book(_h_Kpi[ix][iy], 1, 1 + ix, 1 + iy);
}
book(_b[ix], {0., .795, .995, 1.332, 1.532, 10.});
for (unsigned int iy = 0; iy < 5; ++iy) book(_b[ix]->bin(iy + 1), 3, 1 + ix, 1 + iy);
for (unsigned int iy = 0; iy < 3; ++iy) {
book(_h_PsiPi[ix][iy], 5, 1 + ix, 1 + iy);
}
}
}
/// Perform the per-event analysis
void analyze(const Event& event) {
static const map<PdgId, unsigned int>& mode1 = {{321, 1}, {-211, 1}, {443, 1}};
static const map<PdgId, unsigned int>& mode1CC = {{-321, 1}, {211, 1}, {443, 1}};
static const map<PdgId, unsigned int>& mode2 = {{321, 1}, {-211, 1}, {100443, 1}};
static const map<PdgId, unsigned int>& mode2CC = {{-321, 1}, {211, 1}, {100443, 1}};
static const map<PdgId, unsigned int>& mode3 = {{310, 1}, {-211, 1}, {443, 1}};
static const map<PdgId, unsigned int>& mode3CC = {{310, 1}, {211, 1}, {443, 1}};
static const map<PdgId, unsigned int>& mode4 = {{310, 1}, {-211, 1}, {100443, 1}};
static const map<PdgId, unsigned int>& mode4CC = {{310, 1}, {211, 1}, {100443, 1}};
DecayedParticles BB = apply<DecayedParticles>(event, "BB");
// loop over particles
for (unsigned int ix = 0; ix < BB.decaying().size(); ++ix) {
int sign = 1, iK(0), iPsi(0);
if (BB.decaying()[ix].pid() > 0 && BB.modeMatches(ix, 3, mode1)) {
sign = 1;
iK = 321;
iPsi = 443;
}
else if (BB.decaying()[ix].pid() < 0 && BB.modeMatches(ix, 3, mode1CC)) {
sign = -1;
iK = -321;
iPsi = 443;
}
else if (BB.decaying()[ix].pid() > 0 && BB.modeMatches(ix, 3, mode2)) {
sign = 1;
iK = 321;
iPsi = 100443;
}
else if (BB.decaying()[ix].pid() < 0 && BB.modeMatches(ix, 3, mode2CC)) {
sign = -1;
iK = -321;
iPsi = 100443;
}
else if (BB.decaying()[ix].pid() < 0 && BB.modeMatches(ix, 3, mode3)) {
sign = 1;
iK = 310;
iPsi = 443;
}
else if (BB.decaying()[ix].pid() > 0 && BB.modeMatches(ix, 3, mode3CC)) {
sign = -1;
iK = 310;
iPsi = 443;
}
else if (BB.decaying()[ix].pid() < 0 && BB.modeMatches(ix, 3, mode4)) {
sign = 1;
iK = 310;
iPsi = 100443;
}
else if (BB.decaying()[ix].pid() > 0 && BB.modeMatches(ix, 3, mode4CC)) {
sign = -1;
iK = 310;
iPsi = 100443;
}
else
continue;
_c[iPsi / 100000]->fill();
const Particle& Kp = BB.decayProducts()[ix].at(iK)[0];
const Particle& pim = BB.decayProducts()[ix].at(-211 * sign)[0];
const Particle& psi = BB.decayProducts()[ix].at(iPsi)[0];
FourMomentum pKpi = Kp.momentum() + pim.momentum();
double mKpi = pKpi.mass();
_h_Kpi[BB.decaying()[ix].abspid() % 100 / 10 - 1][iPsi / 100000]->fill(mKpi);
_h_Kpi2[iPsi / 100000]->fill(mKpi);
double mPsiPi = (psi.momentum() + pim.momentum()).mass();
_b[iPsi / 100000]->fill(mKpi, mPsiPi);
_h_PsiPi[iPsi / 100000][0]->fill(mPsiPi);
// helicity angle
if (mKpi < 0.795 || (mKpi > 0.995 && mKpi < 1.332) || mKpi > 1.532) {
_h_PsiPi[iPsi / 100000][2]->fill(mPsiPi);
LorentzTransform boost1 = LorentzTransform::mkFrameTransformFromBeta(
BB.decaying()[ix].momentum().betaVec());
pKpi = boost1.transform(pKpi);
Vector3 axis1 = pKpi.p3().unit();
LorentzTransform boost3 = LorentzTransform::mkFrameTransformFromBeta(pKpi.betaVec());
FourMomentum ppi = boost3.transform(boost1.transform(pim.momentum()));
double cPi = ppi.p3().unit().dot(axis1);
_h_angle[iPsi / 100000]->fill(cPi);
}
else {
_h_PsiPi[iPsi / 100000][1]->fill(mPsiPi);
}
}
}
/// Normalise histograms etc., after the run
void finalize() {
for (unsigned int ix = 0; ix < 2; ++ix) {
normalize(_h_Kpi2[ix], 1., false);
normalize(_h_angle[ix], 1., false);
for (unsigned int iy = 0; iy < 2; ++iy) {
normalize(_h_Kpi[ix][iy], 1., false);
}
for (unsigned int iy = 0; iy < 3; ++iy) {
scale(_h_PsiPi[ix][iy], 1. / *_c[ix]);
}
scale(_b[ix], 1. / *_c[ix]);
}
}
/// @}
/// @name Histograms
/// @{
Histo1DPtr _h_Kpi[2][2], _h_Kpi2[2], _h_angle[2], _h_PsiPi[2][3];
Histo1DGroupPtr _b[2];
CounterPtr _c[2];
/// @}
};
RIVET_DECLARE_PLUGIN(BABAR_2009_I801589);
}