diff --git a/src/Event.cc b/src/Event.cc index c17e540..7df221a 100644 --- a/src/Event.cc +++ b/src/Event.cc @@ -1,488 +1,486 @@ /** * \authors Jeppe Andersen, Tuomas Hapola, Marian Heil, Andreas Maier, Jennifer Smillie * \date 2019 * \copyright GPLv2 or later */ #include "HEJ/Event.hh" #include #include #include #include #include "LHEF/LHEF.h" #include "fastjet/JetDefinition.hh" #include "HEJ/Constants.hh" #include "HEJ/exceptions.hh" #include "HEJ/PDG_codes.hh" namespace HEJ{ namespace{ constexpr int status_in = -1; constexpr int status_decayed = 2; constexpr int status_out = 1; /// @name helper functions to determine event type //@{ /** * \brief check if final state valid for HEJ * * check if there is at most one photon, W, H, Z in the final state * and all the rest are quarks or gluons */ bool final_state_ok(std::vector const & outgoing){ bool has_AWZH_boson = false; for(auto const & out: outgoing){ if(is_AWZH_boson(out.type)){ if(has_AWZH_boson) return false; has_AWZH_boson = true; } else if(! is_parton(out.type)) return false; } return true; } template Iterator remove_AWZH(Iterator begin, Iterator end){ return std::remove_if( begin, end, [](Particle const & p){return is_AWZH_boson(p);} ); } template bool valid_outgoing(Iterator begin, Iterator end){ return std::distance(begin, end) >= 2 && std::is_sorted(begin, end, rapidity_less{}) && std::count_if( begin, end, [](Particle const & s){return is_AWZH_boson(s);} ) < 2; } /// @note that this changes the outgoing range! template bool is_FKL( ConstIterator begin_incoming, ConstIterator end_incoming, Iterator begin_outgoing, Iterator end_outgoing ){ assert(std::distance(begin_incoming, end_incoming) == 2); assert(std::distance(begin_outgoing, end_outgoing) >= 2); // One photon, W, H, Z in the final state is allowed. // Remove it for remaining tests, end_outgoing = remove_AWZH(begin_outgoing, end_outgoing); // Test if this is a standard FKL configuration. return (begin_incoming->type == begin_outgoing->type) && ((end_incoming-1)->type == (end_outgoing-1)->type) && std::all_of( begin_outgoing + 1, end_outgoing - 1, [](Particle const & p){ return p.type == pid::gluon; } ); } bool is_FKL( std::array const & incoming, std::vector outgoing ){ assert(std::is_sorted(begin(incoming), end(incoming), pz_less{})); assert(valid_outgoing(begin(outgoing), end(outgoing))); return is_FKL( begin(incoming), end(incoming), begin(outgoing), end(outgoing) ); } bool has_2_jets(Event const & event){ return event.jets().size() >= 2; } /** * \brief Checks whether event is unordered backwards * @param ev Event * @returns Is Event Unordered Backwards * * - Checks there is more than 3 constuents in the final state * - Checks there is more than 3 jets * - Checks the most backwards parton is a gluon * - Checks the most forwards jet is not a gluon * - Checks the rest of the event is FKL * - Checks the second most backwards is not a different boson * - Checks the unordered gluon actually forms a jet */ bool is_unordered_backward(Event const & ev){ auto const & in = ev.incoming(); auto const & out = ev.outgoing(); assert(std::is_sorted(begin(in), end(in), pz_less{})); assert(valid_outgoing(begin(out), end(out))); if(out.size() < 3) return false; if(ev.jets().size() < 3) return false; if(in.front().type == pid::gluon) return false; if(out.front().type != pid::gluon) return false; // When skipping the unordered emission // the remainder should be a regular FKL event, // except that the (new) first outgoing particle must not be a A,W,Z,H. const auto FKL_begin = next(begin(out)); if(is_AWZH_boson(*FKL_begin)) return false; if(!is_FKL(in, {FKL_begin, end(out)})) return false; // check that the unordered gluon forms an extra jet const auto jets = sorted_by_rapidity(ev.jets()); const auto indices = ev.particle_jet_indices({jets.front()}); return indices[0] >= 0 && indices[1] == -1; } /** * \brief Checks for a forward unordered gluon emission * @param ev Event * @returns Is the event a forward unordered emission * * \see is_unordered_backward */ bool is_unordered_forward(Event const & ev){ auto const & in = ev.incoming(); auto const & out = ev.outgoing(); assert(std::is_sorted(begin(in), end(in), pz_less{})); assert(valid_outgoing(begin(out), end(out))); if(out.size() < 3) return false; if(ev.jets().size() < 3) return false; if(in.back().type == pid::gluon) return false; if(out.back().type != pid::gluon) return false; // When skipping the unordered emission // the remainder should be a regular FKL event, // except that the (new) last outgoing particle must not be a A,W,Z,H. const auto FKL_end = prev(end(out)); if(is_AWZH_boson(*prev(FKL_end))) return false; if(!is_FKL(in, {begin(out), FKL_end})) return false; // check that the unordered gluon forms an extra jet const auto jets = sorted_by_rapidity(ev.jets()); const auto indices = ev.particle_jet_indices({jets.back()}); return indices.back() >= 0 && indices[indices.size()-2] == -1; } using event_type::EventType; EventType classify(Event const & ev){ if(! final_state_ok(ev.outgoing())) return EventType::bad_final_state; if(! has_2_jets(ev)) return EventType::no_2_jets; if(is_FKL(ev.incoming(), ev.outgoing())) return EventType::FKL; if(is_unordered_backward(ev)){ return EventType::unordered_backward; } if(is_unordered_forward(ev)){ return EventType::unordered_forward; } return EventType::nonHEJ; } //@} Particle extract_particle(LHEF::HEPEUP const & hepeup, int i){ const ParticleID id = static_cast(hepeup.IDUP[i]); const fastjet::PseudoJet momentum{ hepeup.PUP[i][0], hepeup.PUP[i][1], hepeup.PUP[i][2], hepeup.PUP[i][3] }; if(is_parton(id)) return Particle{ id, std::move(momentum), hepeup.ICOLUP[i] }; return Particle{ id, std::move(momentum), {} }; } bool is_decay_product(std::pair const & mothers){ if(mothers.first == 0) return false; return mothers.second == 0 || mothers.first == mothers.second; } } // namespace anonymous UnclusteredEvent::UnclusteredEvent(LHEF::HEPEUP const & hepeup): central(EventParameters{ hepeup.scales.mur, hepeup.scales.muf, hepeup.weight() }) { size_t in_idx = 0; for (int i = 0; i < hepeup.NUP; ++i) { // skip decay products // we will add them later on, but we have to ensure that // the decayed particle is added before if(is_decay_product(hepeup.MOTHUP[i])) continue; auto particle = extract_particle(hepeup, i); // needed to identify mother particles for decay products particle.p.set_user_index(i+1); if(hepeup.ISTUP[i] == status_in){ if(in_idx > incoming.size()) { throw std::invalid_argument{ "Event has too many incoming particles" }; } incoming[in_idx++] = std::move(particle); } else outgoing.emplace_back(std::move(particle)); } // add decay products for (int i = 0; i < hepeup.NUP; ++i) { if(!is_decay_product(hepeup.MOTHUP[i])) continue; const int mother_id = hepeup.MOTHUP[i].first; const auto mother = std::find_if( begin(outgoing), end(outgoing), [mother_id](Particle const & particle){ return particle.p.user_index() == mother_id; } ); if(mother == end(outgoing)){ throw std::invalid_argument{"invalid decay product parent"}; } const int mother_idx = std::distance(begin(outgoing), mother); assert(mother_idx >= 0); decays[mother_idx].emplace_back(extract_particle(hepeup, i)); } } namespace { int connect_incoming(Particle & part, int & colour, int & anti_colour){ // TODO something is wrong here part.colour = std::make_pair(anti_colour, colour); // gluon if(part.type == pid::gluon) { return 0; } // q if(part.type > 0){ part.colour->second = 0; colour*=-1; return -1; } // qx part.colour->first = 0; anti_colour*=-1; return +1; } } void UnclusteredEvent::generate_colour_flow(RNG & ran){ sort(); // initialise first int colour = COLOUR_OFFSET; int anti_colour = colour+1; // -1 anti, 0 no, +1 colour int is_quark_line = connect_incoming(incoming[0], colour, anti_colour); for(auto & part: outgoing){ - std::cout << part.type << " " << part.rapidity() << " " << colour - << " " << anti_colour << " " << is_quark_line << std::endl; if(part.type == ParticleID::gluon){ // gluon if(is_quark_line == 0){ // on g line => connect to colour OR anti-colour (random) if(ran.flat() < 0.5){ part.colour = std::make_pair(colour+2,colour); colour+=2; } else { part.colour = std::make_pair(anti_colour, anti_colour+2); anti_colour+=2; } } else if(is_quark_line > 0){ // on q line => connect to available colour part.colour = std::make_pair(colour+2, colour); colour+=2; } else { // on qx line => connect to available anti-colour part.colour = std::make_pair(anti_colour, anti_colour+2); anti_colour+=2; } } else if(is_quark(part)) { // quark if(is_quark_line == 0){ // on g line => connect and remove colour is_quark_line = 1; part.colour = std::make_pair(anti_colour, 0); anti_colour+=2; anti_colour*=-1; } else if(is_quark_line < 0){ // on qx line => new colour is_quark_line = 0; colour*=-1; part.colour = std::make_pair(colour,0); } else { throw std::logic_error("Colour connection impossible: Expected anti-quark but found quark."); } } else if(is_antiquark(part)) { // anti-quark if(is_quark_line == 0){ // on g line => connect and remove anti-colour is_quark_line = -1; part.colour = std::make_pair(0, colour); colour+=2; colour*=-1; } else if(is_quark_line > 0){ // on q line => new anti-colour is_quark_line = 0; anti_colour*=-1; part.colour = std::make_pair(0,anti_colour); } else { throw std::logic_error("Colour connection impossible: Expected quark but found anti-quark."); } } } // Connect last connect_incoming(incoming[1], anti_colour, colour); } void UnclusteredEvent::sort(){ // sort incoming std::sort( begin(incoming), end(incoming), [](Particle o1, Particle o2){return o1.p.pz() idx(old_outgoing.size()); std::iota(idx.begin(), idx.end(), 0); std::sort(idx.begin(), idx.end(), [&old_outgoing](size_t i, size_t j){ return old_outgoing[i].rapidity() < old_outgoing[j].rapidity(); }); outgoing.clear(); outgoing.reserve(old_outgoing.size()); for(size_t i: idx) { outgoing.emplace_back(std::move(old_outgoing[i])); } // find decays again if(!decays.empty()){ auto old_decays = std::move(decays); decays.clear(); for(size_t i=0; isecond)); } assert(old_decays.size() == decays.size()); } } Event::Event( UnclusteredEvent ev, fastjet::JetDefinition const & jet_def, double min_jet_pt ): ev_{std::move(ev)}, cs_{to_PseudoJet(filter_partons(ev_.outgoing)), jet_def}, min_jet_pt_{min_jet_pt} { // sort particles ev_.sort(); // classify event type_ = classify(*this); assert(std::is_sorted(begin(outgoing()), end(outgoing()), rapidity_less{})); } std::vector Event::jets() const{ return cs_.inclusive_jets(min_jet_pt_); } double shat(Event const & ev){ return (ev.incoming()[0].p + ev.incoming()[1].p).m2(); } namespace{ // colour flow according to Les Houches standard // TODO: stub std::vector> colour_flow( std::array const & incoming, std::vector const & outgoing ){ std::vector> result( incoming.size() + outgoing.size() ); for(auto & col: result){ col = std::make_pair(-1, -1); } return result; } } LHEF::HEPEUP to_HEPEUP(Event const & event, LHEF::HEPRUP * heprup){ LHEF::HEPEUP result; result.heprup = heprup; result.weights = {{event.central().weight, nullptr}}; for(auto const & var: event.variations()){ result.weights.emplace_back(var.weight, nullptr); } size_t num_particles = event.incoming().size() + event.outgoing().size(); for(auto const & decay: event.decays()) num_particles += decay.second.size(); result.NUP = num_particles; // the following entries are pretty much meaningless result.IDPRUP = event.type()+1; // event ID result.AQEDUP = 1./128.; // alpha_EW //result.AQCDUP = 0.118 // alpha_QCD // end meaningless part result.XWGTUP = event.central().weight; result.SCALUP = event.central().muf; result.scales.muf = event.central().muf; result.scales.mur = event.central().mur; result.scales.SCALUP = event.central().muf; result.pdfinfo.p1 = event.incoming().front().type; result.pdfinfo.p2 = event.incoming().back().type; result.pdfinfo.scale = event.central().muf; for(Particle const & in: event.incoming()){ result.IDUP.emplace_back(in.type); result.ISTUP.emplace_back(status_in); result.PUP.push_back({in.p[0], in.p[1], in.p[2], in.p[3], in.p.m()}); result.MOTHUP.emplace_back(0, 0); } for(size_t i = 0; i < event.outgoing().size(); ++i){ Particle const & out = event.outgoing()[i]; result.IDUP.emplace_back(out.type); const int status = event.decays().count(i)?status_decayed:status_out; result.ISTUP.emplace_back(status); result.PUP.push_back({out.p[0], out.p[1], out.p[2], out.p[3], out.p.m()}); result.MOTHUP.emplace_back(1, 2); } result.ICOLUP = colour_flow( event.incoming(), filter_partons(event.outgoing()) ); if(result.ICOLUP.size() < num_particles){ const size_t AWZH_boson_idx = std::find_if( begin(event.outgoing()), end(event.outgoing()), [](Particle const & s){ return is_AWZH_boson(s); } ) - begin(event.outgoing()) + event.incoming().size(); assert(AWZH_boson_idx <= result.ICOLUP.size()); result.ICOLUP.insert( begin(result.ICOLUP) + AWZH_boson_idx, std::make_pair(0,0) ); } for(auto const & decay: event.decays()){ for(auto const out: decay.second){ result.IDUP.emplace_back(out.type); result.ISTUP.emplace_back(status_out); result.PUP.push_back({out.p[0], out.p[1], out.p[2], out.p[3], out.p.m()}); const size_t mother_idx = 1 + event.incoming().size() + decay.first; result.MOTHUP.emplace_back(mother_idx, mother_idx); result.ICOLUP.emplace_back(0,0); } } assert(result.ICOLUP.size() == num_particles); static constexpr double unknown_spin = 9.; //per Les Houches accord result.VTIMUP = std::vector(num_particles, unknown_spin); result.SPINUP = result.VTIMUP; return result; } }