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| // -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Event.hh"
#include "Rivet/Math/LorentzTrans.hh"
#include "Rivet/Particle.hh"
#include "Rivet/Projections/ChargedLeptons.hh"
#include "Rivet/Projections/DressedLeptons.hh"
#include "Rivet/Projections/FastJets.hh"
#include "Rivet/Projections/FinalState.hh"
#include "Rivet/Projections/IdentifiedFinalState.hh"
#include "Rivet/Projections/MissingMomentum.hh"
#include "Rivet/Projections/PromptFinalState.hh"
#include "Rivet/Projections/VetoedFinalState.hh"
#include "Rivet/Projections/InvisibleFinalState.hh"
namespace Rivet {
/// @brief Measurement of Wgamma differential cross sections in proton-proton collisions at sqrt(s) = 13 TeV and effective field theory constraints
class CMS_2021_I1978840 : public Analysis {
public:
struct WGammaRivetVariables {
bool is_wg_gen;
double l0_pt;
double l0_eta;
double l0_phi;
double l0_M;
int l0_q;
unsigned l0_abs_pdgid;
double p0_pt;
double p0_eta;
double p0_phi;
double p0_M;
bool p0_frixione;
double p0_frixione_sum;
double l0p0_dr;
double mt_cluster;
double n0_pt;
double n0_eta;
double n0_phi;
double n0_M;
double met_pt;
double met_phi;
double true_phi;
double true_phi_f;
int n_jets;
WGammaRivetVariables() { resetVars(); }
void resetVars() {
is_wg_gen = false;
l0_pt = 0.;
l0_eta = 0.;
l0_phi = 0.;
l0_M = 0.;
l0_q = 0;
l0_abs_pdgid = 0;
p0_pt = 0.;
p0_eta = 0.;
p0_phi = 0.;
p0_M = 0.;
p0_frixione = false;
n0_pt = 0.;
n0_eta = 0.;
n0_phi = 0.;
n0_M = 0.;
met_pt = 0.;
met_phi = 0.;
true_phi = 0.;
true_phi_f = 0.;
l0p0_dr = 0.;
mt_cluster = 0.;
n_jets = 0;
}
};
struct WGSystem {
int lepton_charge;
FourMomentum wg_system;
FourMomentum c_w_boson;
FourMomentum c_charged_lepton;
FourMomentum c_neutrino;
FourMomentum c_photon;
FourMomentum r_w_boson;
FourMomentum r_charged_lepton;
FourMomentum r_neutrino;
FourMomentum r_photon;
WGSystem(Particle const& lep, FourMomentum const& neu, Particle const& pho, bool verbose);
double Phi();
double SymPhi();
};
double photon_iso_dr_ = 0.4;
double lepton_pt_cut_ = 30.;
double lepton_abs_eta_cut_ = 2.5;
double photon_pt_cut_ = 30.;
double photon_abs_eta_cut_ = 2.5;
double missing_pt_cut_ = 40.;
double lepton_photon_dr_cut_ = 0.7;
double dressed_lepton_cone_ = 0.1;
double eft_lepton_pt_cut_ = 80.;
double eft_photon_pt_cut_ = 150.;
double jet_pt_cut_ = 30.;
double jet_abs_eta_cut_ = 2.5;
double jet_dr_cut_ = 0.4;
WGammaRivetVariables vars_;
map<string, Histo1DPtr> _h;
RIVET_DEFAULT_ANALYSIS_CTOR(CMS_2021_I1978840);
void init() {
vars_.resetVars();
FinalState fs;
declare(fs, "FinalState");
// Jets - all final state particles excluding neutrinos
VetoedFinalState vfs;
vfs.vetoNeutrinos();
FastJets fastjets(vfs, FastJets::ANTIKT, 0.4);
declare(fastjets, "Jets");
// Dressed leptons
ChargedLeptons charged_leptons(fs);
PromptFinalState prompt_leptons(charged_leptons);
declare(prompt_leptons, "PromptLeptons");
IdentifiedFinalState photons(fs);
photons.acceptIdPair(PID::PHOTON);
PromptFinalState prompt_photons(photons);
prompt_photons.acceptMuonDecays(true);
prompt_photons.acceptTauDecays(true);
DressedLeptons dressed_leptons(prompt_photons, prompt_leptons, dressed_lepton_cone_,
Cuts::open(),
/*useDecayPhotons*/ false);
declare(dressed_leptons, "DressedLeptons");
// Photons
VetoedFinalState vetoed_prompt_photons(prompt_photons);
vetoed_prompt_photons.addVetoOnThisFinalState(dressed_leptons);
declare(vetoed_prompt_photons, "Photons");
// Invisibles
InvisibleFinalState invisibles(true, true, true);
declare(invisibles, "Invisibles");
// MET
declare(MissingMomentum(fs), "MET");
// Booking of histograms
book(_h["baseline_photon_pt"], 1, 1, 1);
book(_h["baseline_photon_eta"], 8, 1, 1);
book(_h["baseline_leppho_dr"], 15, 1, 1);
book(_h["baseline_leppho_deta"], 22, 1, 1);
book(_h["baseline_mt_cluster"], 29, 1, 1);
book(_h["baseline_njet"], 36, 1, 1);
book(_h["raz_leppho_deta"], 40, 1, 1);
book(_h["eft_photon_pt_phi_0"], 54, 1, 1);
book(_h["eft_photon_pt_phi_1"], 55, 1, 1);
book(_h["eft_photon_pt_phi_2"], 56, 1, 1);
}
/// Perform the per-event analysis
void analyze(const Event& event) {
vars_.resetVars();
const Particles leptons = apply<FinalState>(event, "DressedLeptons").particlesByPt();
if (leptons.size() == 0) {
vetoEvent;
}
auto l0 = leptons.at(0);
const Particles photons = apply<FinalState>(event, "Photons")
.particlesByPt(DeltaRGtr(l0, lepton_photon_dr_cut_));
if (photons.size() == 0) {
vetoEvent;
}
auto p0 = photons.at(0);
const Particles invisibles = apply<FinalState>(event, "Invisibles").particlesByPt();
FourMomentum n0;
for (auto const& inv : invisibles) {
n0 += inv.momentum();
}
if (invisibles.size() == 0) {
vetoEvent;
}
FourMomentum met = apply<MissingMomentum>(event, "MET").missingMomentum();
// Redefine the MET
met = FourMomentum(met.pt(), met.px(), met.py(), 0.);
// Filter jets on pT, eta and DR with lepton and photon
const Jets jets = apply<FastJets>(event, "Jets").jetsByPt([&](Jet const& j) {
return j.pt() > jet_pt_cut_ && std::abs(j.eta()) < jet_abs_eta_cut_ &&
deltaR(j, l0) > jet_dr_cut_ && deltaR(j, p0) > jet_dr_cut_;
});
if (leptons.size() >= 1 && photons.size() >= 1 && invisibles.size() >= 1) {
// Populate variables
vars_.is_wg_gen = true;
vars_.l0_pt = l0.pt();
vars_.l0_eta = l0.eta();
vars_.l0_phi = l0.phi(PhiMapping::MINUSPI_PLUSPI);
vars_.l0_M = l0.mass();
vars_.l0_q = l0.charge3() / 3;
vars_.l0_abs_pdgid = std::abs(l0.pid());
vars_.p0_pt = p0.pt();
vars_.p0_eta = p0.eta();
vars_.p0_phi = p0.phi(PhiMapping::MINUSPI_PLUSPI);
vars_.p0_M = p0.mass();
vars_.n_jets = jets.size();
vars_.l0p0_dr = deltaR(l0, p0);
vars_.n0_pt = n0.pt();
vars_.n0_eta = n0.eta();
vars_.n0_phi = n0.phi(PhiMapping::MINUSPI_PLUSPI);
vars_.n0_M = n0.mass();
vars_.met_pt = met.pt();
vars_.met_phi = met.phi(PhiMapping::MINUSPI_PLUSPI);
// Here we build a list of particles to cluster jets, to be used in the photon isolation.
// The selection of particles that we want to veto from this isolation sum is non-trivial:
// the leading pT lepton, the leading pT photon that has DeltaR > 0.7 from the leading pT
// lepton, the invisibles and any tau decay products. Therefore, the selection is done
// here instead of in the initialise method.
Particles finalparts_iso = apply<FinalState>(event, "FinalState").particles();
Particles filtered_iso;
for (Particle const& p : finalparts_iso) {
bool veto_particle = false;
if (p.genParticle() == l0.genParticle() || p.genParticle() == p0.genParticle() || p.fromTau()) {
veto_particle = true;
}
for (auto const& inv : invisibles) {
if (p.genParticle() == inv.genParticle()) {
veto_particle = true;
}
}
if (!veto_particle) {
filtered_iso.push_back(p);
}
}
auto proj = getProjection<FastJets>("Jets");
proj.reset();
proj.calc(filtered_iso);
auto jets_iso = proj.jets();
vars_.p0_frixione = true;
double frixione_sum = 0.;
// Apply Frixione isolation to the photon:
auto jparts = sortBy(jets_iso, [&](Jet const& part1, Jet const& part2) {
return deltaR(part1, p0) < deltaR(part2, p0);
});
for (auto const& ip : jparts) {
double dr = deltaR(ip, p0);
if (dr >= photon_iso_dr_) {
break;
}
frixione_sum += ip.pt();
if (frixione_sum > (p0.pt() * ((1. - std::cos(dr)) / (1. - std::cos(photon_iso_dr_))))) {
vars_.p0_frixione = false;
}
}
// Now calculate EFT phi observables
auto wg_system = WGSystem(l0, n0, p0, false);
vars_.true_phi = wg_system.Phi();
vars_.true_phi_f = wg_system.SymPhi();
// Calculate mTcluster
auto cand1 = l0.momentum() + p0.momentum();
auto full_system = cand1 + met;
double mTcluster2 =
std::pow(std::sqrt(cand1.mass2() + cand1.pt2()) + met.pt(), 2) - full_system.pt2();
if (mTcluster2 > 0) {
vars_.mt_cluster = std::sqrt(mTcluster2);
} else {
vars_.mt_cluster = 0.;
}
if (vars_.l0_pt > lepton_pt_cut_ && std::abs(vars_.l0_eta) < lepton_abs_eta_cut_ &&
vars_.p0_pt > photon_pt_cut_ && std::abs(vars_.p0_eta) < photon_abs_eta_cut_ &&
vars_.p0_frixione && vars_.l0p0_dr > lepton_photon_dr_cut_ &&
vars_.met_pt > missing_pt_cut_) {
_h["baseline_photon_pt"]->fill(vars_.p0_pt / GeV);
_h["baseline_photon_eta"]->fill(vars_.p0_eta);
_h["baseline_leppho_dr"]->fill(vars_.l0p0_dr);
_h["baseline_leppho_deta"]->fill(vars_.l0_eta - vars_.p0_eta);
_h["baseline_mt_cluster"]->fill(vars_.mt_cluster / GeV);
double fill_n_jets = vars_.n_jets >= 2 ? 2. : double(vars_.n_jets);
_h["baseline_njet"]->fill(fill_n_jets);
if (vars_.n_jets == 0 && vars_.mt_cluster > 150.) {
_h["raz_leppho_deta"]->fill(vars_.l0_eta - vars_.p0_eta);
}
}
if (vars_.l0_pt > eft_lepton_pt_cut_ && std::abs(vars_.l0_eta) < lepton_abs_eta_cut_ &&
vars_.p0_pt > eft_photon_pt_cut_ && std::abs(vars_.p0_eta) < photon_abs_eta_cut_ &&
vars_.p0_frixione && vars_.l0p0_dr > lepton_photon_dr_cut_ &&
vars_.met_pt > missing_pt_cut_ && vars_.n_jets == 0) {
double absphi = std::abs(vars_.true_phi_f);
if (absphi > 0. && absphi <= (PI / 6.)) {
_h["eft_photon_pt_phi_0"]->fill(vars_.p0_pt / GeV);
} else if (absphi > (PI / 6.) && absphi <= (PI / 3.)) {
_h["eft_photon_pt_phi_1"]->fill(vars_.p0_pt / GeV);
} else if (absphi > (PI / 3.) && absphi <= (PI / 2.)) {
_h["eft_photon_pt_phi_2"]->fill(vars_.p0_pt / GeV);
}
}
}
}
void finalize() {
double flavor_factor = 3. / 2.; // account for the fact that tau events are vetoed
// Scale according to cross section
for (std::string const& x :
{"baseline_photon_pt", "baseline_photon_eta", "baseline_leppho_dr", "baseline_leppho_deta",
"baseline_mt_cluster", "baseline_njet", "raz_leppho_deta", "eft_photon_pt_phi_0",
"eft_photon_pt_phi_1", "eft_photon_pt_phi_2"}) {
scale(_h[x], flavor_factor * crossSection() / femtobarn / sumOfWeights());
}
// Since these are really 2D, we need to divide by the y bin width:
for (std::string const& x :
{"eft_photon_pt_phi_0", "eft_photon_pt_phi_1", "eft_photon_pt_phi_2"}) {
scale(_h[x], 1. / (PI / 6.));
}
}
};
CMS_2021_I1978840::WGSystem::WGSystem(Particle const& lep, FourMomentum const& neu,
Particle const& pho, bool verbose) {
lepton_charge = lep.charge3() / 3;
wg_system += lep.momentum();
wg_system += neu;
wg_system += pho.momentum();
if (verbose) {
std::cout << "> charge: " << lepton_charge << "\n";
std::cout << "> wg_system: " << wg_system << "\n";
std::cout << "> lepton : " << lep.momentum() << "\n";
std::cout << "> neutrino : " << neu << "\n";
std::cout << "> photon : " << pho.momentum() << "\n";
}
auto boost = LorentzTransform::mkFrameTransformFromBeta(wg_system.betaVec());
c_charged_lepton = boost.transform(lep);
c_neutrino = boost.transform(neu);
c_photon = boost.transform(pho);
if (verbose) {
std::cout << "> c_lepton : " << c_charged_lepton << "\n";
std::cout << "> c_neutrino : " << c_neutrino << "\n";
std::cout << "> c_photon : " << c_photon << "\n";
}
FourMomentum c_w_boson;
c_w_boson += c_charged_lepton;
c_w_boson += c_neutrino;
auto r_uvec = wg_system.vector3().unit();
if (verbose) {
std::cout << "> c_w_boson : " << c_w_boson << "\n";
std::cout << "> r_uvec : " << r_uvec << "\n";
}
auto z_uvec = c_w_boson.vector3().unit();
auto y_uvec = z_uvec.cross(r_uvec).unit();
auto x_uvec = y_uvec.cross(z_uvec).unit();
if (verbose) {
std::cout << "> x_uvec : " << x_uvec << "\n";
std::cout << "> y_uvec : " << y_uvec << "\n";
std::cout << "> z_uvec : " << z_uvec << "\n";
}
Matrix3 rot_matrix;
rot_matrix.setRow(0, x_uvec).setRow(1, y_uvec).setRow(2, z_uvec);
auto rotator = LorentzTransform();
rotator = rotator.postMult(rot_matrix);
if (verbose) {
std::cout << "> rotator : " << rotator << "\n";
}
r_w_boson = rotator.transform(c_w_boson);
r_charged_lepton = rotator.transform(c_charged_lepton);
r_neutrino = rotator.transform(c_neutrino);
r_photon = rotator.transform(c_photon);
if (verbose) {
std::cout << "> r_lepton : " << r_charged_lepton << "\n";
std::cout << "> r_neutrino : " << r_neutrino << "\n";
std::cout << "> r_photon : " << r_photon << "\n";
std::cout << "> r_w_boson : " << r_w_boson << "\n";
}
}
double CMS_2021_I1978840::WGSystem::Phi() {
double lep_phi = r_charged_lepton.phi(PhiMapping::MINUSPI_PLUSPI);
return mapAngleMPiToPi(lepton_charge > 0 ? (lep_phi) : (lep_phi + PI));
}
double CMS_2021_I1978840::WGSystem::SymPhi() {
double lep_phi = Phi();
if (lep_phi > PI / 2.) {
return PI - lep_phi;
} else if (lep_phi < -1. * (PI / 2.)) {
return -1. * (PI + lep_phi);
} else {
return lep_phi;
}
}
RIVET_DECLARE_PLUGIN(CMS_2021_I1978840);
} // namespace Rivet
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