diff --git a/src/Event.cc b/src/Event.cc
index be795e0..0cb4ca0 100644
--- a/src/Event.cc
+++ b/src/Event.cc
@@ -1,927 +1,870 @@
/**
* \authors The HEJ collaboration (see AUTHORS for details)
* \date 2019
* \copyright GPLv2 or later
*/
#include "HEJ/Event.hh"
#include <algorithm>
#include <assert.h>
#include <numeric>
#include <utility>
#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<Particle> 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<class Iterator>
Iterator remove_AWZH(Iterator begin, Iterator end){
return std::remove_if(
begin, end, [](Particle const & p){return is_AWZH_boson(p);}
);
}
template<class Iterator>
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;
}
/**
* \brief function which determines if type change is consistent with W emission.
* @param in incoming Particle
* @param out outgoing Particle
*
* Ensures that change type of quark line is possible by a flavour changing
* W emission.
*/
bool is_W_Current(ParticleID in, ParticleID out){
if((in==1 && out==2)||(in==2 && out==1)){
return true;
}
else if((in==-1 && out==-2)||(in==-2 && out==-1)){
return true;
}
else if((in==3 && out==4)||(in==4 && out==3)){
return true;
}
else if((in==-3 && out==-4)||(in==-4 && out==-3)){
return true;
}
else{
return false;
}
}
/**
* \brief checks if particle type remains same from incoming to outgoing
* @param in incoming Particle
* @param out outgoing Particle
*/
bool is_Pure_Current(ParticleID in, ParticleID out){
if(abs(in)<=6 || in==21) return (in==out);
else return false;
}
// @note that this changes the outgoing range!
template<class ConstIterator, class Iterator>
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);
if(std::all_of(
begin_outgoing + 1, end_outgoing - 1,
[](Particle const & p){ return p.type == pid::gluon; })
){
// Test if this is a standard FKL configuration.
if (is_Pure_Current(begin_incoming->type, begin_outgoing->type)
&& is_Pure_Current((end_incoming-1)->type, (end_outgoing-1)->type)){
return true;
}
}
return false;
}
template<class ConstIterator, class Iterator>
bool is_W_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);
if(std::all_of(
begin_outgoing + 1, end_outgoing - 1,
[](Particle const & p){ return p.type == pid::gluon; })
){
// Test if this is a standard FKL configuration.
if(is_W_Current(begin_incoming->type, begin_outgoing->type)
&& is_Pure_Current((end_incoming-1)->type, (end_outgoing-1)->type)){
return true;
}
else if(is_Pure_Current(begin_incoming->type, begin_outgoing->type)
&& is_W_Current((end_incoming-1)->type, (end_outgoing-1)->type)){
return true;
}
}
return false;
}
bool is_FKL(
std::array<Particle, 2> const & incoming,
std::vector<Particle> outgoing
){
assert(std::is_sorted(begin(incoming), end(incoming), pz_less{}));
assert(valid_outgoing(begin(outgoing), end(outgoing)));
const auto WEmit = std::find_if(
begin(outgoing), end(outgoing),
[](Particle const & s){ return abs(s.type) == pid::Wp; }
);
if (WEmit != end(outgoing) && abs(WEmit->type) == pid::Wp){
return is_W_FKL(
begin(incoming), end(incoming),
begin(outgoing), end(outgoing)
);
}
else{
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 = 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 = ev.jets();
const auto indices = ev.particle_jet_indices({jets.back()});
return indices.back() >= 0 && indices[indices.size()-2] == -1;
}
-
/**
- * \brief Checks for a forward extremal qqx
+ * \brief Checks for an extremal qqx (forwards, reverse input for back)
* @param ev Event
* @returns Is the event a forward extremal qqx event
*
* Checks there is 3 or more than 3 constituents in the final state
* Checks there is 3 or more than 3 jets
* Checks most forwards incoming is gluon
* Checks most extremal particle is not a Higgs (either direction)
* Checks the second most forwards particle is not Higgs boson
* Checks remaining chain is pure gluon
* Checks the most forwards parton is a either quark or anti-quark.
* Checks the second most forwards parton is anti-quark or quark.
* Checks the qqbar pair form 2 separate jets.
+ * Checks other current logically consistent (with/out W emission.)
*/
- bool is_Ex_qqxf(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)));
-
- int fkl_start=is_AWZ_boson(out.front());
+ template<class InIterator, class OutIterator, class JetIterator, class IndIterator>
+ bool is_Ex_qqx(
+ InIterator begin_in, InIterator end_in,
+ OutIterator begin_out, OutIterator end_out,
+ JetIterator begin_jets, JetIterator end_jets,
+ IndIterator end_indices
+ ){
+ int fkl_start=is_AWZ_boson(begin_out->type);
int fkl_end=2;
- 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::Higgs || out.front().type == pid::Higgs
- || out.rbegin()[1].type == pid::Higgs) return false;
+ if(std::distance(begin_out, (end_out)) < 3) return false;
+ if(std::distance(begin_jets, (end_jets)) < 3) return false;
+ if((end_in-1)->type != pid::gluon) return false;
+ if((end_out-1)->type == pid::Higgs || begin_out->type == pid::Higgs
+ || (end_out-2)->type == pid::Higgs) return false;
- // if extremal AWZ
- if(is_AWZ_boson(out.back())){ // if extremal AWZ
+ if(is_AWZ_boson((end_out-1)->type)){ // if extremal AWZ
++fkl_end;
- if (is_quark(out.rbegin()[1])){ //if second quark
- if (!(is_antiquark(out.rbegin()[2]))) return false;// third must be anti-quark
+ if (is_quark((end_out-2)->type)){ //if second quark
+ if (!(is_antiquark((end_out-3)->type))) return false;// third must be anti-quark
}
- else if (is_antiquark(out.rbegin()[1])){ //if second anti-quark
- if (!(is_quark(out.rbegin()[2]))) return false;// third must be quark
+ else if (is_antiquark((end_out-2)->type)){ //if second anti-quark
+ if (!(is_quark((end_out-3)->type))) return false;// third must be quark
}
else return false;
}
- else if (is_quark(out.rbegin()[0])){ //if extremal quark
- if(is_AWZ_boson(out.rbegin()[1])){ // if second AWZ
+ else if (is_quark((end_out-1)->type)){ //if extremal quark
+ if(is_AWZ_boson((end_out-2)->type)){ // if second AWZ
++fkl_end;
- if (!(is_antiquark(out.rbegin()[2]))) return false;// third must be anti-quark
+ if (!(is_antiquark((end_out-3)->type))) return false;// third must be anti-quark
}
- else if (!(is_antiquark(out.rbegin()[1]))) return false;// second must be anti-quark
+ else if (!(is_antiquark((end_out-2)->type))) return false;// second must be anti-quark
}
- else if (is_antiquark(out.rbegin()[0])){ //if extremal anti-quark
- if(is_AWZ_boson(out.rbegin()[1])){ // if second AWZ
+ else if (is_antiquark((end_out-1)->type)){ //if extremal anti-quark
+ if(is_AWZ_boson((end_out-2)->type)){ // if second AWZ
++fkl_end;
- if (!(is_quark(out.rbegin()[2]))) return false;// third must be quark
+ if (!(is_quark((end_out-3)->type))) return false;// third must be quark
}
- else if (!(is_quark(out.rbegin()[1]))) return false;// second must be quark
+ else if (!(is_quark((end_out-2)->type))) return false;// second must be quark
}
else return false;
- // When skipping the qqbar
- // New last outgoing particle must not be a Higgs
- if (out.rbegin()[fkl_end].type == pid::Higgs) return false;
-
// no other quark emission (first doesn't matter)
if(std::any_of(
- out.begin()+1+fkl_start, out.end()-fkl_end,
+ begin_out+1+fkl_start, end_out-1-fkl_end,
[](Particle const & p){ return is_anyquark(p); })
) return false;
- const auto & jets = ev.jets();
- const auto indices = ev.particle_jet_indices({jets});
-
- // Ensure qqbar pair are in separate jets
- if(indices[indices.size()-2] != indices[indices.size()-1]-1) return false;
+ // // Ensure qqbar pair are in separate jets
+ if((end_indices-3)[0] != (end_indices-2)[0]-1) return false;
// Opposite current should be logical to process
- if (is_AWZ_boson(out.front().type)){
- return (is_Pure_Current(in.front().type, out[1].type)
- || is_W_Current(in.front().type,out[1].type));
+ if (is_AWZ_boson(begin_out->type)){
+ return (is_Pure_Current(begin_in->type, (begin_out+1)->type)
+ || is_W_Current(begin_in->type,(begin_out+1)->type));
}
- return (is_Pure_Current(in.front().type, out[0].type)
- || is_W_Current(in.front().type,out[0].type));
+ return (is_Pure_Current(begin_in->type, begin_out->type)
+ || is_W_Current(begin_in->type,begin_out->type));
+ }
+
+ /**
+ * \brief Checks for a forward extremal qqx
+ * @param ev Event
+ * @returns Is the event a forward extremal qqx event
+ *
+ * \see is_Ex_qqx()
+ */
+ bool is_Ex_qqxf(Event const & ev){
+ // const auto & indices = ev.particle_jet_indices({ev.jets()});
+ assert(std::is_sorted(begin(in), end(in), pz_less{}));
+ assert(valid_outgoing(begin(out), end(out)));
+ return is_Ex_qqx(cbegin(ev.incoming()), cend(ev.incoming()),
+ cbegin(ev.outgoing()), cend(ev.outgoing()),
+ cbegin(ev.jets()), cend(ev.jets()),
+ cend(ev.particle_jet_indices({ev.jets()})));
}
/**
* \brief Checks for a backward extremal qqx
* @param ev Event
* @returns Is the event a backward extremal qqx event
*
- * Checks there is 3 or more than 3 constituents in the final state
- * Checks there is 3 or more than 3 jets
- * Checks most backwards incoming is gluon
- * Checks most extremal particle is not a Higgs (either direction) y
- * Checks the second most backwards particle is not Higgs boson y
- * Checks remaining chain is pure gluon
- * Checks the most backwards parton is a either quark or anti-quark. y
- * Checks the second most backwards parton is anti-quark or quark. y
- * Checks the qqbar pair form 2 separate jets.
+ * \see is_Ex_qqx()
*/
bool is_Ex_qqxb(Event const & ev){
- auto const & in = ev.incoming();
- auto const & out = ev.outgoing();
+ // const auto & indices = ev.particle_jet_indices({ev.jets()});
assert(std::is_sorted(begin(in), end(in), pz_less{}));
assert(valid_outgoing(begin(out), end(out)));
-
- int fkl_start=2;
- int fkl_end=is_AWZ_boson(out.back());
-
- if(out.size() < 3) return false;
- if(ev.jets().size() < 3) return false;
- if(in.front().type != pid::gluon) return false;
- if(out.back().type == pid::Higgs || out.front().type == pid::Higgs
- || out[1].type == pid::Higgs) return false;
-
- // @TODO why don't we test to the Higgs as well? i.e. is_AWZH_boson
- if(is_AWZ_boson(out.front())){ // if extremal AWZ
- ++fkl_start;
- if (is_quark(out[1])){ //if second quark
- if (!(is_antiquark(out[2]))) return false;// third must be anti-quark
- }
- else if (is_antiquark(out[1])){ //if second anti-quark
- if (!(is_quark(out[2]))) return false;// third must be quark
- }
- else return false;
- }
- else if (is_quark(out[0])){ // if extremal quark
- if(is_AWZ_boson(out[1])){ // if second AWZ
- ++fkl_start;
- if (!(is_antiquark(out[2]))) return false;// third must be anti-quark
- }
- else if (!(is_antiquark(out[1]))) return false;// second must be anti-quark
- }
- else if (is_antiquark(out[0])){ //if extremal anti-quark
- if(is_AWZ_boson(out[1])){ // if second AWZ
- ++fkl_start;
- if (!(is_quark(out[2]))) return false;// third must be quark
- }
- else if (!(is_quark(out[1]))) return false;// second must be quark
- }
- else return false;
-
- // When skipping the qqbar
- // New last outgoing particle must not be a Higgs.
- if (out[fkl_start].type == pid::Higgs) return false;
-
- // no other quark emission (last doesn't matter)
- if(std::any_of(
- out.cbegin()+fkl_start, out.cend()-1-fkl_end,
- [](Particle const & p){ return is_anyquark(p); })
- ) return false;
-
- const auto & jets = ev.jets();
- const auto indices = ev.particle_jet_indices({jets});
-
- // Ensure qqbar pair form separate jets.
- if(indices[0] != indices[1]-1) return false;
-
- // Other current should be logical to process
- if (is_AWZ_boson(out.back())){
- return (is_Pure_Current(in.back().type, out.rbegin()[1].type)
- || is_W_Current(in.back().type,out.rbegin()[1].type));
- }
- else
- return (is_Pure_Current(in.back().type, out.rbegin()[0].type)
- || is_W_Current(in.back().type, out.rbegin()[0].type));
+ return is_Ex_qqx(crbegin(ev.incoming()), crend(ev.incoming()),
+ crbegin(ev.outgoing()), crend(ev.outgoing()),
+ crbegin(ev.jets()), crend(ev.jets()),
+ cend(ev.particle_jet_indices({ev.jets()})));
}
-
/**
* \brief Checks for a central qqx
* @param ev Event
* @returns Is the event a central extremal qqx event
*
* Checks there is 4 or more than 4 constuents in the final state
* Checks there is 4 or more than 4 jets
* Checks most extremal particle is not a Higgs (either direction) y
* Checks for a central quark in the outgoing states
* Checks for adjacent anti-quark parton. (allowing for AWZ boson emission between)
* Check that other partons are only gluons in chain
* Checks external currents are logically sound.
*/
bool is_Mid_qqx(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() < 4) return false;
if(ev.jets().size() < 4) return false;
if(out.back().type == pid::Higgs || out.front().type == pid::Higgs)
return false;
size_t start_FKL=0;
size_t end_FKL=0;
if (is_AWZ_boson(out.back())){
++end_FKL;
}
if (is_AWZ_boson(out.front())){
++start_FKL;
}
if ((is_Pure_Current(in.back().type,out.rbegin()[end_FKL].type)
&& is_Pure_Current(in.front().type,out[start_FKL].type))){
//nothing to do
}
else if (is_W_Current(in.back().type,out.rbegin()[end_FKL].type)
&& is_Pure_Current(in.front().type,out[start_FKL].type)){
//nothing to do
}
else if (!(is_Pure_Current(in.back().type,out.rbegin()[end_FKL].type)
&& is_W_Current(in.front().type,out[start_FKL].type))){
return false;
}
const auto & jets = ev.jets();
const auto indices = ev.particle_jet_indices({jets});
auto const out_partons = filter_partons(out);
// search for qqx pair
for (size_t i = 1; i<out_partons.size()-2; ++i){
if ((is_quark(out_partons[i]) && (is_antiquark(out_partons[i+1])))
|| (is_antiquark(out_partons[i]) && (is_quark(out_partons[i+1])))
){
// no quarks before qqx (beside first)
if(std::any_of(
out_partons.cbegin()+1, out_partons.cbegin()+i,
[](Particle const & p){ return is_anyquark(p); })
) return false;
// no quarks after qqx (beside last)
if(std::any_of(
out_partons.cbegin()+i+2, out_partons.cend()-1,
[](Particle const & p){ return is_anyquark(p); })
) return false;
// should be in seperate jets
return (indices[i+1] == indices[i]+1 && indices[i] != -1);
}
}
return false;
}
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;
if(is_Ex_qqxb(ev))
return EventType::extremal_qqxb;
if(is_Ex_qqxf(ev))
return EventType::extremal_qqxf;
if(is_Mid_qqx(ev))
return EventType::central_qqx;
return EventType::nonHEJ;
}
//@}
Particle extract_particle(LHEF::HEPEUP const & hepeup, int i){
const ParticleID id = static_cast<ParticleID>(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<int, int> const & mothers){
if(mothers.first == 0) return false;
return mothers.second == 0 || mothers.first == mothers.second;
}
} // namespace anonymous
Event::EventData::EventData(LHEF::HEPEUP const & hepeup){
parameters.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));
}
}
Event::Event(
UnclusteredEvent const & ev,
fastjet::JetDefinition const & jet_def, double const min_jet_pt
):
Event( Event::EventData{
ev.incoming, ev.outgoing, ev.decays,
Parameters<EventParameters>{ev.central, ev.variations}
}.cluster(jet_def, min_jet_pt) )
{}
//! @TODO remove in HEJ 2.2.0
UnclusteredEvent::UnclusteredEvent(LHEF::HEPEUP const & hepeup){
Event::EventData const evData{hepeup};
incoming = evData.incoming;
outgoing = evData.outgoing;
decays = evData.decays;
central = evData.parameters.central;
variations = evData.parameters.variations;
}
void Event::EventData::sort(){
// sort particles
std::sort(
begin(incoming), end(incoming),
[](Particle o1, Particle o2){return o1.p.pz()<o2.p.pz();}
);
auto old_outgoing = std::move(outgoing);
std::vector<size_t> 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; i<idx.size(); ++i) {
auto decay = old_decays.find(idx[i]);
if(decay != old_decays.end())
decays.emplace(i, std::move(decay->second));
}
assert(old_decays.size() == decays.size());
}
}
namespace {
Particle reconstruct_boson(std::vector<Particle> const & leptons) {
HEJ::Particle decayed_boson;
decayed_boson.p = leptons[0].p + leptons[1].p;
const int pidsum = leptons[0].type + leptons[1].type;
if(pidsum == +1) {
assert(is_antilepton(leptons[0]));
if(is_antineutrino(leptons[0])) {
throw HEJ::not_implemented{"lepton-flavour violating final state"};
}
assert(is_neutrino(leptons[1]));
// charged antilepton + neutrino means we had a W+
decayed_boson.type = HEJ::pid::Wp;
}
else if(pidsum == -1) {
assert(is_antilepton(leptons[0]));
if(is_neutrino(leptons[1])) {
throw HEJ::not_implemented{"lepton-flavour violating final state"};
}
assert(is_antineutrino(leptons[0]));
// charged lepton + antineutrino means we had a W-
decayed_boson.type = HEJ::pid::Wm;
}
else {
throw HEJ::not_implemented{
"final state with leptons "
+ HEJ::name(leptons[0].type)
+ " and "
+ HEJ::name(leptons[1].type)
};
}
return decayed_boson;
}
}
void HEJ::Event::EventData::reconstruct_intermediate() {
const auto begin_leptons = std::partition(
begin(outgoing), end(outgoing),
[](HEJ::Particle const & p) {return !HEJ::is_anylepton(p);}
);
if(begin_leptons == end(outgoing)) return;
assert(is_anylepton(*begin_leptons));
std::vector<HEJ::Particle> leptons(begin_leptons, end(outgoing));
outgoing.erase(begin_leptons, end(outgoing));
if(leptons.size() != 2) {
throw HEJ::not_implemented{"Final states with one or more than two leptons"};
}
std::sort(
begin(leptons), end(leptons),
[](HEJ::Particle const & p0, HEJ::Particle const & p1) {
return p0.type < p1.type;
}
);
outgoing.emplace_back(reconstruct_boson(leptons));
decays.emplace(outgoing.size()-1, std::move(leptons));
}
Event Event::EventData::cluster(
fastjet::JetDefinition const & jet_def, double const min_jet_pt
){
sort();
Event ev{ std::move(incoming), std::move(outgoing), std::move(decays),
std::move(parameters),
jet_def, min_jet_pt
};
assert(std::is_sorted(begin(ev.outgoing_), end(ev.outgoing_),
rapidity_less{}));
ev.type_ = classify(ev);
return ev;
}
Event::Event(
std::array<Particle, 2> && incoming,
std::vector<Particle> && outgoing,
std::unordered_map<size_t, std::vector<Particle>> && decays,
Parameters<EventParameters> && parameters,
fastjet::JetDefinition const & jet_def,
double const min_jet_pt
): incoming_{std::move(incoming)},
outgoing_{std::move(outgoing)},
decays_{std::move(decays)},
parameters_{std::move(parameters)},
cs_{ to_PseudoJet( filter_partons(outgoing_) ), jet_def },
min_jet_pt_{min_jet_pt}
{
jets_ = sorted_by_rapidity(cs_.inclusive_jets(min_jet_pt_));
}
namespace {
void connect_incoming(Particle & in, int & colour, int & anti_colour){
in.colour = std::make_pair(anti_colour, colour);
// gluon
if(in.type == pid::gluon)
return;
if(in.type > 0){
// quark
assert(is_quark(in));
in.colour->second = 0;
colour*=-1;
return;
}
// anti-quark
assert(is_antiquark(in));
in.colour->first = 0;
anti_colour*=-1;
return;
}
}
bool Event::generate_colours(RNG & ran){
// generate only for HEJ events
if(!event_type::is_HEJ(type()))
return false;
assert(std::is_sorted(
begin(outgoing()), end(outgoing()), rapidity_less{}));
assert(incoming()[0].pz() < incoming()[1].pz());
// positive (anti-)colour -> can connect
// negative (anti-)colour -> not available/used up by (anti-)quark
int colour = COLOUR_OFFSET;
int anti_colour = colour+1;
// initialise first
connect_incoming(incoming_[0], colour, anti_colour);
for(auto & part: outgoing_){
assert(colour>0 || anti_colour>0);
if(part.type == ParticleID::gluon){
// gluon
if(colour>0 && anti_colour>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(colour > 0){
// on q line => connect to available colour
part.colour = std::make_pair(colour+2, colour);
colour+=2;
} else {
assert(colour<0 && anti_colour>0);
// 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
assert(anti_colour>0);
if(colour>0){
// on g line => connect and remove anti-colour
part.colour = std::make_pair(anti_colour, 0);
anti_colour+=2;
anti_colour*=-1;
} else {
// on qx line => new colour
colour*=-1;
part.colour = std::make_pair(colour, 0);
}
} else if(is_antiquark(part)) {
// anti-quark
assert(colour>0);
if(anti_colour>0){
// on g line => connect and remove colour
part.colour = std::make_pair(0, colour);
colour+=2;
colour*=-1;
} else {
// on q line => new anti-colour
anti_colour*=-1;
part.colour = std::make_pair(0, anti_colour);
}
}
// else not a parton
}
// Connect last
connect_incoming(incoming_[1], anti_colour, colour);
return true;
} // generate_colours
namespace {
void print_momentum(std::ostream & os, fastjet::PseudoJet const & part){
const std::streamsize orig_prec = os.precision();
os <<std::scientific<<std::setprecision(6) << "["
<<std::setw(13)<<std::right<< part.px() << ", "
<<std::setw(13)<<std::right<< part.py() << ", "
<<std::setw(13)<<std::right<< part.pz() << ", "
<<std::setw(13)<<std::right<< part.E() << "]"<< std::fixed;
os.precision(orig_prec);
}
}
std::ostream& operator<<(std::ostream & os, Event const & ev){
const std::streamsize orig_prec = os.precision();
os <<std::setprecision(4)<<std::fixed;
std::cout << "########## " << event_type::names[ev.type()] << " ##########" << std::endl;
std::cout << "Incoming particles:\n";
for(auto const & in: ev.incoming()){
std::cout <<std::setw(3)<< in.type << ": ";
print_momentum(os, in.p);
std::cout << std::endl;
}
std::cout << "\nOutgoing particles: " << ev.outgoing().size() << "\n";
for(auto const & out: ev.outgoing()){
std::cout <<std::setw(3)<< out.type << ": ";
print_momentum(os, out.p);
std::cout << " => rapidity="
<<std::setw(7)<<std::right<< out.rapidity() << std::endl;
}
std::cout << "\nForming Jets: " << ev.jets().size() << "\n";
for(auto const & jet: ev.jets()){
print_momentum(os, jet);
std::cout << " => rapidity="
<<std::setw(7)<<std::right<< jet.rapidity() << std::endl;
}
os << std::defaultfloat;
os.precision(orig_prec);
return os;
}
double shat(Event const & ev){
return (ev.incoming()[0].p + ev.incoming()[1].p).m2();
}
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;
result.IDUP.reserve(num_particles); // PID
result.ISTUP.reserve(num_particles); // status (in, out, decay)
result.PUP.reserve(num_particles); // momentum
result.MOTHUP.reserve(num_particles); // index mother particle
result.ICOLUP.reserve(num_particles); // colour
// incoming
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);
assert(in.colour);
result.ICOLUP.emplace_back(*in.colour);
}
// outgoing
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);
if(out.colour)
result.ICOLUP.emplace_back(*out.colour);
else{
assert(is_AWZH_boson(out));
result.ICOLUP.emplace_back(std::make_pair(0,0));
}
}
// decays
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<double>(num_particles, unknown_spin);
result.SPINUP = result.VTIMUP;
return result;
}
}