diff --git a/FixedOrderGen/include/PhaseSpacePoint.hh b/FixedOrderGen/include/PhaseSpacePoint.hh
index f1d122b..f89ab03 100644
--- a/FixedOrderGen/include/PhaseSpacePoint.hh
+++ b/FixedOrderGen/include/PhaseSpacePoint.hh
@@ -1,296 +1,298 @@
 /** \file      PhaseSpacePoint.hh
  *  \brief     Contains the PhaseSpacePoint Class
  *
  *  \authors   The HEJ collaboration (see AUTHORS for details)
  *  \date      2019-2020
  *  \copyright GPLv2 or later
  */
 #pragma once
 
 #include <array>
 #include <bitset>
 #include <cstddef>
 #include <unordered_map>
 #include <vector>
 
 #include "boost/iterator/filter_iterator.hpp"
 
 #include "HEJ/Event.hh"
 #include "HEJ/PDG_codes.hh"
 #include "HEJ/Particle.hh"
 
 #include "fastjet/PseudoJet.hh"
 
 #include "Decay.hh"
 #include "Status.hh"
 #include "Subleading.hh"
 
 namespace HEJ {
   class EWConstants;
   class PDF;
   class RNG;
 }
 
 namespace HEJFOG {
   struct JetParameters;
   struct Process;
 
   //! A point in resummation phase space
   class PhaseSpacePoint{
   public:
 
     //! Iterator over partons
     using ConstPartonIterator = boost::filter_iterator<
       bool (*)(HEJ::Particle const &),
       std::vector<HEJ::Particle>::const_iterator
       >;
     //! Reverse Iterator over partons
     using ConstReversePartonIterator = std::reverse_iterator<
                                                 ConstPartonIterator>;
 
     //! Default PhaseSpacePoint Constructor
     PhaseSpacePoint() = delete;
 
     //! PhaseSpacePoint Constructor
     /**
      * @param proc                  The process to generate
      * @param jet_param             Jet defintion & cuts
      * @param pdf                   The pdf set (used for sampling)
      * @param E_beam                Energie of the beam
      * @param subl_chance           Chance to turn a potentially unordered
      *                              emission into an actual one
      * @param subl_channels         Possible subleading channels.
      *                              see HEJFOG::Subleading
      * @param particle_properties   Properties of producted boson
      *
      * Initially, only FKL phase space points are generated. subl_chance gives
      * the chance of turning one emissions into a subleading configuration,
      * i.e. either unordered or central quark/anti-quark pair. Unordered
      * emissions require that the most extremal emission in any direction is
      * a quark or anti-quark and the next emission is a gluon. Quark/anti-quark
      * pairs are only generated for W processes. At most one subleading
      * emission will be generated in this way.
      */
     PhaseSpacePoint(
       Process const & proc,
       JetParameters const & jet_param,
       HEJ::PDF & pdf, double E_beam,
       double subl_chance,
       Subleading subl_channels,
       ParticlesDecayMap const & particle_decays,
       HEJ::EWConstants const & ew_parameters,
       HEJ::RNG & ran
     );
 
     //! Get Weight Function
     /**
      * @returns        Weight of Event
      */
     double weight() const{
       return weight_;
     }
 
     Status status() const{
       return status_;
     }
 
     //! Get Incoming Function
     /**
      * @returns        Incoming Particles
      */
     std::array<HEJ::Particle, 2> const & incoming() const{
       return incoming_;
     }
 
     //! Get Outgoing Function
     /**
      * @returns        Outgoing Particles
      */
     std::vector<HEJ::Particle> const & outgoing() const{
       return outgoing_;
     }
 
     std::unordered_map<std::size_t, std::vector<HEJ::Particle>> const & decays() const{
       return decays_;
     }
 
     //! Iterator to the first outgoing parton
     ConstPartonIterator begin_partons() const;
     //! Iterator to the first outgoing parton
     ConstPartonIterator cbegin_partons() const;
 
     //! Iterator to the end of the outgoing partons
     ConstPartonIterator end_partons() const;
     //! Iterator to the end of the outgoing partons
     ConstPartonIterator cend_partons() const;
 
     //! Reverse Iterator to the first outgoing parton
     ConstReversePartonIterator rbegin_partons() const;
     //! Reverse Iterator to the first outgoing parton
     ConstReversePartonIterator crbegin_partons() const;
     //! Reverse Iterator to the first outgoing parton
     ConstReversePartonIterator rend_partons() const;
     //! Reverse Iterator to the first outgoing parton
     ConstReversePartonIterator crend_partons() const;
 
   private:
     static constexpr std::size_t NUM_PARTONS = 11; //!< Number of partons
   public:
     using part_mask = std::bitset<NUM_PARTONS>; //!< Selection mask for partons
   private:
     friend HEJ::Event::EventData to_EventData(PhaseSpacePoint psp);
     /**
      * @internal
      * @brief Generate LO parton momentum
      *
      * @param np                Number of partons to generate
      * @param is_pure_jets      If true ensures momentum conservation in x and y
      * @param jet_param         Jet properties to fulfil
      * @param max_pt            max allowed pt for a parton (typically E_CMS)
      * @param ran               Random Number Generator
      *
      * @returns                 Momentum of partons
      *
      * Ensures that each parton is in its own jet.
      * Generation is independent of parton flavour. Output is sorted in rapidity.
      */
     std::vector<fastjet::PseudoJet> gen_LO_partons(
         int np, bool is_pure_jets,
         JetParameters const & jet_param,
         double max_pt,
         HEJ::RNG & ran
     );
     HEJ::Particle gen_boson(
         HEJ::ParticleID bosonid, double mass, double width,
         HEJ::RNG & ran
     );
+    double gen_V_boson_rapidity(HEJ::RNG & ran);
+    double gen_Higgs_rapidity(HEJ::RNG & ran);
     template<class ParticleMomenta>
     fastjet::PseudoJet gen_last_momentum(
         ParticleMomenta const & other_momenta,
         double mass_square, double y
     ) const;
 
     bool jets_ok(
         std::vector<fastjet::PseudoJet> const & Born_jets,
         std::vector<fastjet::PseudoJet> const & partons
     ) const;
     /**
      * @internal
      * @brief Generate incoming partons according to the PDF
      *
      * @param uf                Scale used in the PDF
      */
     void reconstruct_incoming(
         Process const & proc,
         double subl_chance, Subleading subl_channels,
         HEJ::PDF & pdf, double E_beam,
         double uf,
         HEJ::RNG & ran
     );
     HEJ::ParticleID generate_incoming_id(
         std::size_t beam_idx, double x, double uf, HEJ::PDF & pdf,
         part_mask allowed_partons, HEJ::RNG & ran
     );
     //! @brief Returns list of all allowed initial states partons
     std::array<part_mask,2> allowed_incoming(
         Process const & proc,
         double subl_chance, Subleading subl_channels,
         HEJ::RNG & ran
     );
 
     //! Ensure that incoming state compatible with A/W/Z production
     std::array<part_mask,2> incoming_AWZ(
         Process const & proc, Subleading subl_channels,
         std::array<part_mask,2> allowed_partons,
         HEJ::RNG & ran
     );
     //! Ensure that incoming state compatible with extremal qqbar
     std::array<part_mask,2> incoming_eqqbar(
         std::array<part_mask,2> allowed_partons, HEJ::RNG & ran);
     //! Ensure that incoming state compatible with unordered
     std::array<part_mask,2> incoming_uno(
         std::array<part_mask,2> allowed_partons, HEJ::RNG & ran);
 
     bool momentum_conserved(double ep) const;
 
     bool extremal_FKL_ok(
         std::vector<fastjet::PseudoJet> const & partons
     ) const;
     double random_normal(double stddev, HEJ::RNG & ran);
     /**
      * @internal
      * @brief Turns a FKL configuration into a subleading one
      *
      * @param chance            Chance to switch to subleading configuration
      * @param channels          Allowed channels for subleading process
      * @param proc              Process to decide which subleading
      *                          configurations are allowed
      *
      * With a chance of "chance" the FKL configuration is either turned into
      * a unordered configuration or, for A/W/Z bosons, a configuration with
      * a central quark/anti-quark pair.
      */
     void maybe_turn_to_subl(double chance, Subleading channels,
         Process const & proc, HEJ::RNG & ran);
     void turn_to_subl(
         Subleading channels,
         bool can_be_uno_backward, bool can_be_uno_forward, bool allow_strange,
         HEJ::RNG & ran);
     void turn_to_uno(bool can_be_uno_backward, bool can_be_uno_forward,
                      HEJ::RNG & ran);
     HEJ::ParticleID select_qqbar_flavour(bool allow_strange, HEJ::RNG & ran);
     void turn_to_cqqbar(bool allow_strange, HEJ::RNG & ran);
     void turn_to_eqqbar(bool allow_strange, HEJ::RNG & ran);
     //! decay where we select the decay channel
     std::vector<HEJ::Particle> decay_channel(
         HEJ::Particle const & parent,
         std::vector<Decay> const & decays,
         HEJ::RNG & ran
     );
     /// @brief setup outgoing partons to ensure correct coupling to boson
     void couple_boson(HEJ::ParticleID boson, HEJ::RNG & ran);
     Decay select_decay_channel(
         std::vector<Decay> const & decays,
         HEJ::RNG & ran
     );
     double gen_hard_pt(
         int np, double ptmin, double ptmax, double y,
         HEJ::RNG & ran
     );
     double gen_soft_pt(int np, double max_pt, HEJ::RNG & ran);
     double gen_parton_pt(
         int count, JetParameters const & jet_param, double max_pt, double y,
         HEJ::RNG & ran
     );
 
     //! Iterator over partons (non-const)
     using PartonIterator = boost::filter_iterator<
       bool (*)(HEJ::Particle const &),
       std::vector<HEJ::Particle>::iterator
       >;
     //! Reverse Iterator over partons (non-const)
     using ReversePartonIterator = std::reverse_iterator<PartonIterator>;
 
     //! Iterator to the first outgoing parton (non-const)
     PartonIterator begin_partons();
     //! Iterator to the end of the outgoing partons (non-const)
     PartonIterator end_partons();
 
     //! Reverse Iterator to the first outgoing parton (non-const)
     ReversePartonIterator rbegin_partons();
     //! Reverse Iterator to the first outgoing parton (non-const)
     ReversePartonIterator rend_partons();
 
     double weight_;
 
     Status status_;
 
     std::array<HEJ::Particle, 2> incoming_;
     std::vector<HEJ::Particle> outgoing_;
     //! Particle decays in the format {outgoing index, decay products}
     std::unordered_map<std::size_t, std::vector<HEJ::Particle>> decays_;
   };
 
   //! Extract HEJ::Event::EventData from PhaseSpacePoint
   HEJ::Event::EventData to_EventData(PhaseSpacePoint psp);
 } // namespace HEJFOG
diff --git a/FixedOrderGen/src/PhaseSpacePoint.cc b/FixedOrderGen/src/PhaseSpacePoint.cc
index f42523f..459fb1f 100644
--- a/FixedOrderGen/src/PhaseSpacePoint.cc
+++ b/FixedOrderGen/src/PhaseSpacePoint.cc
@@ -1,982 +1,1003 @@
 /**
  *  \authors   The HEJ collaboration (see AUTHORS for details)
  *  \date      2019-2020
  *  \copyright GPLv2 or later
  */
 #include "PhaseSpacePoint.hh"
 
 #include <algorithm>
 #include <cassert>
 #include <cmath>
 #include <cstdlib>
 #include <iostream>
 #include <iterator>
 #include <limits>
 #include <tuple>
 #include <type_traits>
 #include <utility>
 
 #include "fastjet/ClusterSequence.hh"
 
 #include "HEJ/Constants.hh"
 #include "HEJ/EWConstants.hh"
 #include "HEJ/PDF.hh"
+#include "HEJ/PDG_codes.hh"
 #include "HEJ/Particle.hh"
 #include "HEJ/RNG.hh"
 #include "HEJ/exceptions.hh"
 #include "HEJ/kinematics.hh"
 #include "HEJ/utility.hh"
 
 #include "JetParameters.hh"
 #include "Process.hh"
 
 namespace HEJFOG {
   HEJ::Event::EventData to_EventData(PhaseSpacePoint psp){
   //! @TODO Same function already in HEJ
     HEJ::Event::EventData result;
     result.incoming = std::move(psp).incoming_; // NOLINT(bugprone-use-after-move)
     result.outgoing = std::move(psp).outgoing_; // NOLINT(bugprone-use-after-move)
     // technically Event::EventData doesn't have to be sorted,
     // but PhaseSpacePoint should be anyway
     assert(
         std::is_sorted(
             begin(result.outgoing), end(result.outgoing),
             HEJ::rapidity_less{}
         )
     );
     assert(result.outgoing.size() >= 2);
     result.decays = std::move(psp).decays_; // NOLINT(bugprone-use-after-move)
     static_assert(
         std::numeric_limits<double>::has_quiet_NaN,
         "no quiet NaN for double"
     );
     constexpr double nan = std::numeric_limits<double>::quiet_NaN();
     result.parameters.central = {nan, nan, psp.weight()}; // NOLINT(bugprone-use-after-move)
     return result;
   }
 
   PhaseSpacePoint::ConstPartonIterator PhaseSpacePoint::begin_partons() const {
     return cbegin_partons();
   }
   PhaseSpacePoint::ConstPartonIterator PhaseSpacePoint::cbegin_partons() const {
     return {HEJ::is_parton, cbegin(outgoing()), cend(outgoing())};
   }
 
   PhaseSpacePoint::ConstPartonIterator PhaseSpacePoint::end_partons() const {
     return cend_partons();
   }
   PhaseSpacePoint::ConstPartonIterator PhaseSpacePoint::cend_partons() const {
     return {HEJ::is_parton, cend(outgoing()), cend(outgoing())};
   }
 
   PhaseSpacePoint::ConstReversePartonIterator PhaseSpacePoint::rbegin_partons() const {
     return crbegin_partons();
   }
   PhaseSpacePoint::ConstReversePartonIterator PhaseSpacePoint::crbegin_partons() const {
     return std::reverse_iterator<ConstPartonIterator>( cend_partons() );
   }
 
   PhaseSpacePoint::ConstReversePartonIterator PhaseSpacePoint::rend_partons() const {
     return crend_partons();
   }
   PhaseSpacePoint::ConstReversePartonIterator PhaseSpacePoint::crend_partons() const {
     return std::reverse_iterator<ConstPartonIterator>( cbegin_partons() );
   }
 
   PhaseSpacePoint::PartonIterator PhaseSpacePoint::begin_partons() {
     return {HEJ::is_parton, begin(outgoing_), end(outgoing_)};
   }
 
   PhaseSpacePoint::PartonIterator PhaseSpacePoint::end_partons() {
     return {HEJ::is_parton, end(outgoing_), end(outgoing_)};
   }
 
   PhaseSpacePoint::ReversePartonIterator PhaseSpacePoint::rbegin_partons() {
     return std::reverse_iterator<PartonIterator>( end_partons() );
   }
 
   PhaseSpacePoint::ReversePartonIterator PhaseSpacePoint::rend_partons() {
     return std::reverse_iterator<PartonIterator>( begin_partons() );
   }
 
   namespace {
     bool can_swap_to_uno(
         HEJ::Particle const & p1, HEJ::Particle const & p2
     ){
       assert(is_parton(p1) && is_parton(p2));
       return p1.type != HEJ::pid::gluon
           && p2.type == HEJ::pid::gluon;
     }
 
     size_t count_gluons(PhaseSpacePoint::ConstPartonIterator first,
                         PhaseSpacePoint::ConstPartonIterator last
     ){
       return std::count_if(first, last, [](HEJ::Particle const & p)
         {return p.type == HEJ::pid::gluon;});
     }
 
     /** assumes FKL configurations between first and last,
      * else there can be a quark in a non-extreme position
      * e.g. uno configuration gqg would pass
      */
     Subleading possible_qqbar(
       PhaseSpacePoint::ConstPartonIterator first,
       PhaseSpacePoint::ConstReversePartonIterator const & last
     ){
       using namespace subleading;
       assert( std::distance( first,last.base() )>2 );
       Subleading channels = ALL;
       channels.reset(eqqbar);
       channels.reset(cqqbar);
       auto const ngluon = count_gluons(first,last.base());
       if(ngluon < 2) return channels;
       if(first->type==HEJ::pid::gluon || last->type==HEJ::pid::gluon){
         channels.set(eqqbar);
       }
       if(std::distance(first,last.base())>=4){
         channels.set(cqqbar);
       }
       return channels;
     }
 
     template<class PartonIt, class OutIt>
     bool uno_possible(
       PartonIt first_parton, OutIt first_out
     ){
       using namespace HEJ;
       // Special case: Higgs can not be outside of uno
       if(first_out->type == pid::Higgs
           || std::next(first_out)->type==pid::Higgs){
         return false;
       }
       // decide what kind of subleading process is allowed
       return can_swap_to_uno( *first_parton, *std::next(first_parton) );
     }
 
     bool is_AWZ_proccess(Process const & proc){
       return proc.boson && HEJ::is_AWZ_boson(*proc.boson);
     }
 
     bool is_up_type(HEJ::Particle const & part){
       return is_anyquark(part) && ((std::abs(part.type)%2) == 0);
     }
     bool is_down_type(HEJ::Particle const & part){
       return is_anyquark(part) && ((std::abs(part.type)%2) != 0);
     }
     bool can_couple_to_W(
         HEJ::Particle const & part, HEJ::pid::ParticleID const W_id
     ){
       const int W_charge = W_id>0?1:-1;
       return std::abs(part.type)<HEJ::pid::b
         && ( (W_charge*part.type > 0 && is_up_type(part))
           || (W_charge*part.type < 0 && is_down_type(part)) );
     }
 
     Subleading ensure_AWZ(
         double & subl_chance, bool & allow_strange,
         HEJ::ParticleID const boson,
         PhaseSpacePoint::ConstPartonIterator first_parton,
         PhaseSpacePoint::ConstPartonIterator last_parton
     ){
       auto channels = subleading::ALL;
       if(std::none_of(first_parton, last_parton,
           [&boson](HEJ::Particle const & p){
             return can_couple_to_W(p, boson);})) {
         // enforce qqbar if A/W/Z can't couple somewhere else
         // this is ensured to work through filter_partons in reconstruct_incoming
         channels.reset(subleading::uno);
         assert(channels.any());
         subl_chance = 1.;
         // strange not allowed for W
         if(std::abs(boson)== HEJ::pid::Wp) allow_strange = false;
       }
       return channels;
     }
   } // namespace
 
   void PhaseSpacePoint::turn_to_subl(
       Subleading const channels,
       bool const can_be_uno_backward, bool const can_be_uno_forward,
       bool const allow_strange,
       HEJ::RNG & ran
   ){
     double const nchannels = channels.count();
     double const step = 1./nchannels;
     weight_*=nchannels;
     unsigned selected = subleading::first;
     double rnd = nchannels>1?ran.flat():0.;
     // @TODO optimise this sampling
     for(; selected<=subleading::last; ++selected){
       assert(rnd>=0);
       if(channels[selected]){
         if(rnd<step) break;
         rnd-=step;
       }
     }
     switch(selected){
       case subleading::uno:
         return turn_to_uno(can_be_uno_backward, can_be_uno_forward, ran);
       case subleading::cqqbar:
         return turn_to_cqqbar(allow_strange, ran);
       case subleading::eqqbar:
         return turn_to_eqqbar(allow_strange, ran);
       default:
         throw std::logic_error{"unreachable"};
     }
   }
 
   void PhaseSpacePoint::maybe_turn_to_subl(
       double chance, Subleading channels, Process const & proc, HEJ::RNG & ran
   ){
     using namespace HEJ;
     if(proc.njets <= 2) return;
     assert(outgoing_.size() >= 2);
 
     // decide what kind of subleading process is allowed
     bool const can_be_uno_backward = uno_possible(cbegin_partons(),
                                                   outgoing_.cbegin());
     bool const can_be_uno_forward  = uno_possible(crbegin_partons(),
                                                   outgoing_.crbegin());
     if(channels[subleading::uno]){
       channels.set(subleading::uno, can_be_uno_backward || can_be_uno_forward);
     }
     channels &= possible_qqbar(cbegin_partons(), crbegin_partons());
 
     bool allow_strange = true;
     if(is_AWZ_proccess(proc)) {
       channels &= ensure_AWZ(chance, allow_strange, *proc.boson,
                              cbegin_partons(), cend_partons());
     }
 
     std::size_t const nchannels = channels.count();
     // no subleading
     if(nchannels==0) return;
     if(ran.flat() >= chance){
       weight_ /= 1 - chance;
       return;
     }
     weight_ /= chance;
 
     // select channel
     return turn_to_subl( channels, can_be_uno_backward, can_be_uno_forward,
       allow_strange, ran);
   }
 
   void PhaseSpacePoint::turn_to_uno(
       const bool can_be_uno_backward, const bool can_be_uno_forward,
       HEJ::RNG & ran
   ){
     if(!can_be_uno_backward && !can_be_uno_forward) return;
     if(can_be_uno_backward && can_be_uno_forward){
       weight_ *= 2.;
       if(ran.flat() < 0.5){
         return std::swap(begin_partons()->type, std::next(begin_partons())->type);
       }
       return std::swap(rbegin_partons()->type, std::next(rbegin_partons())->type);
     }
     if(can_be_uno_backward){
       return std::swap(begin_partons()->type, std::next(begin_partons())->type);
     }
     assert(can_be_uno_forward);
     std::swap(rbegin_partons()->type, std::next(rbegin_partons())->type);
   }
 
   //! select flavour of quark
   HEJ::ParticleID PhaseSpacePoint::select_qqbar_flavour(
       const bool allow_strange, HEJ::RNG & ran
   ){
     const double r1 = 2.*ran.flat()-1.;
     const double max_flavour = allow_strange?HEJ::N_F:HEJ::N_F-1;
     weight_ *= max_flavour*2;
     double const flavour = HEJ::pid::down + std::floor(std::abs(r1)*max_flavour);
     return static_cast<HEJ::ParticleID>(flavour*(r1<0.?-1:1));
   }
 
   void PhaseSpacePoint::turn_to_cqqbar(const bool allow_strange, HEJ::RNG & ran){
     // we assume all FKL partons to be gluons
     auto first = std::next(begin_partons());
     auto last  = std::next(rbegin_partons());
     auto const ng = std::distance(first, last.base());
     if(ng < 2)
       throw std::logic_error("not enough gluons to create qqbar");
     auto flavour = select_qqbar_flavour(allow_strange, ran);
     // select gluon for switch
     if(ng!=2){
       const double steps = 1./(ng-1.);
       weight_ /= steps;
       for(auto rnd = ran.flat(); rnd>steps; ++first){
         rnd-=steps;
       }
     }
     first->type = flavour;
     std::next(first)->type = anti(flavour);
   }
 
   void PhaseSpacePoint::turn_to_eqqbar(const bool allow_strange, HEJ::RNG & ran){
     /// find first and last gluon in FKL chain
     auto first  = begin_partons();
     const bool can_forward = !is_anyquark(*first);
     auto last = rbegin_partons();
     const bool can_backward = !is_anyquark(*last);
     if(std::distance(first, last.base()) < 2)
       throw std::logic_error("not enough gluons to create qqbar");
     auto flavour = select_qqbar_flavour(allow_strange, ran);
     // select gluon for switch
     if(can_forward && !can_backward){
       first->type = flavour;
       std::next(first)->type = anti(flavour);
       return;
     }
     if(!can_forward && can_backward){
       last->type = flavour;
       std::next(last)->type = anti(flavour);
       return;
     }
     assert(can_forward && can_backward);
     weight_*=2.;
     if(ran.flat()>0.5){
       first->type = flavour;
       std::next(first)->type = anti(flavour);
       return;
     }
     last->type = flavour;
     std::next(last)->type = anti(flavour);
   }
 
   template<class ParticleMomenta>
   fastjet::PseudoJet PhaseSpacePoint::gen_last_momentum(
       ParticleMomenta const & other_momenta,
       const double mass_square, const double y
   ) const {
     std::array<double,2> pt{0.,0.};
     for (auto const & p: other_momenta) {
       pt[0]-= p.px();
       pt[1]-= p.py();
     }
 
     const double mperp = std::sqrt(pt[0]*pt[0]+pt[1]*pt[1]+mass_square);
     const double pz=mperp*std::sinh(y);
     const double E=mperp*std::cosh(y);
 
     return {pt[0], pt[1], pz, E};
   }
 
   Decay PhaseSpacePoint::select_decay_channel(
       std::vector<Decay> const & decays,
       HEJ::RNG & ran
   ){
     double br_total = 0.;
     for(auto const & decay: decays) br_total += decay.branching_ratio;
     // adjust weight
     // this is given by (channel branching ratio)/(chance to pick channel)
     // where (chance to pick channel) =
     //       (channel branching ratio)/(total branching ratio)
     weight_ *= br_total;
     if(decays.size()==1) return decays.front();
     const double r1 = br_total*ran.flat();
     double br_sum = 0.;
     for(auto const & decay: decays){
       br_sum += decay.branching_ratio;
       if(r1 < br_sum) return decay;
     }
     throw std::logic_error{"unreachable"};
   }
   namespace {
     //! generate decay products of a boson
     std::vector<HEJ::Particle> decay_boson(
         HEJ::Particle const & parent,
         std::vector<HEJ::ParticleID> const & decays,
         HEJ::RNG & ran
     ){
       if(decays.size() != 2){
         throw HEJ::not_implemented{
           "only decays into two particles are implemented"
         };
       }
       std::vector<HEJ::Particle> decay_products(decays.size());
       for(size_t i = 0; i < decays.size(); ++i){
         decay_products[i].type = decays[i];
       }
       // choose polar and azimuth angle in parent rest frame
       const double E = parent.m()/2;
       const double theta = 2.*M_PI*ran.flat();
       const double cos_phi = 2.*ran.flat()-1.;   // Jacobian Factors for W in line 418
       const double sin_phi = std::sqrt(1. - cos_phi*cos_phi);  // Know 0 < phi < pi
       const double px = E*std::cos(theta)*sin_phi;
       const double py = E*std::sin(theta)*sin_phi;
       const double pz = E*cos_phi;
       decay_products[0].p.reset(px, py, pz, E);
       decay_products[1].p.reset(-px, -py, -pz, E);
       for(auto & particle: decay_products) particle.p.boost(parent.p);
       return decay_products;
     }
   } // namespace
 
   std::vector<HEJ::Particle> PhaseSpacePoint::decay_channel(
       HEJ::Particle const & parent,
       std::vector<Decay> const & decays,
       HEJ::RNG & ran
   ){
     const auto channel = select_decay_channel(decays, ran);
     return decay_boson(parent, channel.products, ran);
   }
 
   namespace {
     //! adds a particle to target (in correct rapidity ordering)
     //! @returns    positon of insertion
     auto insert_particle(std::vector<HEJ::Particle> & target,
       HEJ::Particle && particle
     ){
       const auto pos = std::upper_bound(
           begin(target),end(target),particle,HEJ::rapidity_less{}
       );
       target.insert(pos, std::move(particle));
       return pos;
     }
   } // namespace
 
   PhaseSpacePoint::PhaseSpacePoint(
     Process const & proc,
     JetParameters const & jet_param,
     HEJ::PDF & pdf, double E_beam,
     double const subl_chance,
     Subleading subl_channels,
     ParticlesDecayMap const & particle_decays,
     HEJ::EWConstants const & ew_parameters,
     HEJ::RNG & ran
   ){
     assert(proc.njets >= 2);
     status_ = Status::good;
     weight_ = 1;
 
     // ensure that all setting are consistent
     if(subl_chance == 0.)
       subl_channels.reset();
 
     const std::size_t nout = proc.njets + (proc.boson?1:0)
                               + proc.boson_decay.size();
     outgoing_.reserve(nout);
 
     // generate parton momenta
     const bool is_pure_jets = (nout == proc.njets);
     auto partons = gen_LO_partons(
         proc.njets, is_pure_jets, jet_param, E_beam, ran
     );
     // pre fill flavour with gluons
     for( auto it = std::make_move_iterator(partons.begin());
               it != std::make_move_iterator(partons.end());
             ++it
     ){
       outgoing_.emplace_back(HEJ::Particle{HEJ::pid::gluon, *it, {}});
     }
     if(status_ != Status::good) return;
 
     if(proc.boson){ // decay boson
       auto const & boson_prop = (*proc.boson == HEJ::pid::Z_photon_mix
                                  ? ew_parameters.prop(HEJ::pid::Z)
                                  : ew_parameters.prop(*proc.boson));
       auto boson{ gen_boson(*proc.boson, boson_prop.mass, boson_prop.width, ran) };
       const auto pos{insert_particle(outgoing_, std::move(boson))};
       const size_t boson_idx = std::distance(begin(outgoing_), pos);
       auto const & boson_decay = particle_decays.find(*proc.boson);
       if( !proc.boson_decay.empty() ){ // decay given in proc
         decays_.emplace(
             boson_idx,
             decay_boson(outgoing_[boson_idx], proc.boson_decay, ran)
         );
       } else if( boson_decay != particle_decays.end()
                 && !boson_decay->second.empty() ){ // decay given explicitly
         decays_.emplace(
             boson_idx,
             decay_channel(outgoing_[boson_idx], boson_decay->second, ran)
         );
       }
     }
     // normalisation of momentum-conserving delta function
     weight_ *= std::pow(2*M_PI, 4);
 
     /** @TODO
      *  uf (jet_param.min_pt) doesn't correspond to our final scale choice.
      *  The HEJ scale generators currently expect a full event as input,
      *  so fixing this is not completely trivial
      */
     reconstruct_incoming(proc, subl_chance, subl_channels, pdf, E_beam, jet_param.min_pt, ran);
     if(status_ != Status::good) return;
     // set outgoing states
     begin_partons()->type = incoming_[0].type;
     rbegin_partons()->type = incoming_[1].type;
 
     maybe_turn_to_subl(subl_chance, subl_channels, proc, ran);
 
     if(proc.boson) couple_boson(*proc.boson, ran);
   }
 
   // pt generation, see eq:pt_sampling in developer manual
   double PhaseSpacePoint::gen_hard_pt(
     const int np , const double ptmin, const double ptmax, const double /* y */,
     HEJ::RNG & ran
   ){
     // heuristic parameter for pt sampling, see eq:pt_par in developer manual
     const double ptpar = ptmin + np/5.;
 
     const double arctan = std::atan((ptmax - ptmin)/ptpar);
     const double xpt = ran.flat();
     const double pt = ptmin + ptpar*std::tan(xpt*arctan);
     const double cosine = std::cos(xpt*arctan);
     weight_ *= pt*ptpar*arctan/(cosine*cosine);
     return pt;
   }
 
   double PhaseSpacePoint::gen_soft_pt(int np, double max_pt, HEJ::RNG & ran) {
     constexpr double ptpar = 4.;
 
     const double r = ran.flat();
     const double pt = max_pt + ptpar/np*std::log(r);
     weight_ *= pt*ptpar/(np*r);
     return pt;
   }
 
   double PhaseSpacePoint::gen_parton_pt(
       int count, JetParameters const & jet_param, double max_pt, double y,
       HEJ::RNG & ran
   ) {
     constexpr double p_small_pt = 0.02;
 
     if(! jet_param.peak_pt) {
        return gen_hard_pt(count, jet_param.min_pt, max_pt, y, ran);
     }
     const double r = ran.flat();
     if(r > p_small_pt) {
       weight_ /= 1. - p_small_pt;
       return gen_hard_pt(count, *jet_param.peak_pt, max_pt, y, ran);
     }
     weight_ /= p_small_pt;
     const double pt =  gen_soft_pt(count, *jet_param.peak_pt, ran);
     if(pt < jet_param.min_pt) {
       weight_=0.0;
       status_ = Status::not_enough_jets;
       return jet_param.min_pt;
     }
     return pt;
   }
 
   std::vector<fastjet::PseudoJet> PhaseSpacePoint::gen_LO_partons(
       int np, bool is_pure_jets,
       JetParameters const & jet_param,
       double max_pt,
       HEJ::RNG & ran
   ){
     if (np<2) throw std::invalid_argument{"Not enough partons in gen_LO_partons"};
 
     weight_ /= std::pow(16.*std::pow(M_PI,3),np);
     weight_ /= std::tgamma(np+1); //remove rapidity ordering
     std::vector<fastjet::PseudoJet> partons;
     partons.reserve(np);
     for(int i = 0; i < np; ++i){
       const double y = -jet_param.max_y + 2*jet_param.max_y*ran.flat();
       weight_ *= 2*jet_param.max_y;
 
       const bool is_last_parton = i+1 == np;
       if(is_pure_jets && is_last_parton) {
         constexpr double parton_mass_sq = 0.;
         partons.emplace_back(gen_last_momentum(partons, parton_mass_sq, y));
         break;
       }
 
       const double phi = 2*M_PI*ran.flat();
       weight_ *= 2.0*M_PI;
 
       const double pt = gen_parton_pt(np, jet_param, max_pt, y, ran);
       if(weight_ == 0.0) return {};
 
       partons.emplace_back(fastjet::PtYPhiM(pt, y, phi));
       assert(jet_param.min_pt <= partons[i].pt());
       assert(partons[i].pt() <= max_pt+1e-5);
     }
     // Need to check that at LO, the number of jets = number of partons;
     fastjet::ClusterSequence cs(partons, jet_param.def);
     auto cluster_jets=cs.inclusive_jets(jet_param.min_pt);
     if (cluster_jets.size()!=unsigned(np)){
       weight_=0.0;
       status_ = Status::not_enough_jets;
       return {};
     }
 
     std::sort(begin(partons), end(partons), HEJ::rapidity_less{});
 
     return partons;
   }
 
   HEJ::Particle PhaseSpacePoint::gen_boson(
       HEJ::ParticleID bosonid, double mass, double width,
       HEJ::RNG & ran
   ){
-    // Usual phase space measure
+    // Usual phase space measure for single particle,
+    // see eq:single_particle_phase_space in developer manual
     weight_ /= 16.*std::pow(M_PI, 3);
 
-    // two Gaussians around (+/-)2.6 of std width ~1.8
-    const int backward = int (2*ran.flat()); //0:forward 1:backward
-    // This is not an integral over two distributions, but a random choice of
-    // which option to take, each one representing the full integral.
-    // So the weight of the integral should not be multiplied by 2
-    const double stddev_y = 1.8;
-    double y = random_normal(stddev_y, ran);
-    y+=(1.-2.*backward)*2.6; // add or subtract 2.5
+    const double y = (bosonid == HEJ::pid::Higgs)?
+      gen_Higgs_rapidity(ran):
+      gen_V_boson_rapidity(ran);
 
+    // off-shell sampling, see eq:breit-wigner-sampling in developer manual
     const double r1 = ran.flat();
     const double s_boson = mass*(
         mass + width*std::tan(M_PI/2.*r1 + (r1-1.)*std::atan(mass/width))
     );
-    // off-shell s_boson sampling, compensates for Breit-Wigner
-    /// @TODO use a flag instead
-    if(std::abs(bosonid) == HEJ::pid::Wp || bosonid == HEJ::pid::Z_photon_mix){
-      weight_/=M_PI*M_PI*16.;  //Corrects B-W factors, see git issue 132
+    if(bosonid != HEJ::pid::Higgs){
+      // two-particle phase space,
+      // compare eq:two_particle_phase_space and eq:one_particle_phase_space
+      // in developer manual
+      weight_/=M_PI*M_PI*16.;
+      // Jacobian, see eq:breit-wigner-sampling_jacobian in developer manual
       weight_*= mass*width*( M_PI+2.*std::atan(mass/width) )
               / ( 1. + std::cos( M_PI*r1 + 2.*(r1-1.)*std::atan(mass/width) ) );
     }
 
-    return {  bosonid,
-              gen_last_momentum(outgoing_, s_boson, y),
-              {}
-            };
+    return {
+      bosonid,
+      gen_last_momentum(outgoing_, s_boson, y),
+      {}
+    };
+  }
+
+  double PhaseSpacePoint::gen_Higgs_rapidity(
+    HEJ::RNG & ran
+  ) {
+    constexpr double STDDEV_Y_H = 1.6;
+    return random_normal(STDDEV_Y_H, ran);
+  }
+
+  double PhaseSpacePoint::gen_V_boson_rapidity(
+      HEJ::RNG & ran
+  ){
+    // two Gaussians around (+/-)2.6 of std width ~1.8
+    const int backward = int (2*ran.flat()); //0:forward 1:backward
+    // This is not an integral over two distributions, but a random choice of
+    // which option to take, each one representing the full integral.
+    // So the weight of the integral should not be multiplied by 2
+    constexpr double STDDEV_Y_V = 1.8;
+    const double y = random_normal(STDDEV_Y_V, ran);
+    return y + (1.-2.*backward)*2.6; // add or subtract 2.6
   }
 
   namespace {
     /// partons are ordered: even = anti, 0 = gluon
     HEJ::ParticleID index_to_pid(size_t i){
       if(!i) return HEJ::pid::gluon;
       return static_cast<HEJ::ParticleID>( i%2 ? (i+1)/2 : -i/2 );
     }
 
     /// partons are ordered: even = anti, 0 = gluon
     size_t pid_to_index(HEJ::ParticleID id){
       if(id==HEJ::pid::gluon) return 0;
       return id>0 ? id*2-1 : std::abs(id)*2;
     }
 
     PhaseSpacePoint::part_mask init_allowed(HEJ::ParticleID const id){
       if(std::abs(id) == HEJ::pid::proton)
         return ~0;
       PhaseSpacePoint::part_mask out{0};
       if(HEJ::is_parton(id))
         out[pid_to_index(id)] = true;
       return out;
     }
 
     /// decides which "index" (see index_to_pid) are allowed for process
     PhaseSpacePoint::part_mask allowed_quarks(HEJ::ParticleID const boson){
       if(std::abs(boson) != HEJ::pid::Wp){
         return ~1; // not a gluon
       }
       // special case W:
       // Wp: anti-down or up-type quark, no b/t
       // Wm: down or anti-up-type quark, no b/t
       return boson>0?0b00011001100  // NOLINT(readability-magic-numbers)
                     :0b00100110010; // NOLINT(readability-magic-numbers)
     }
   } // namespace
 
   std::array<PhaseSpacePoint::part_mask,2> PhaseSpacePoint::incoming_AWZ(
       Process const & proc, Subleading const subl_channels,
       std::array<part_mask,2> allowed_partons,
       HEJ::RNG & ran
   ){
     assert(proc.boson);
     auto couple_parton = allowed_quarks(*proc.boson);
     // eqqbar possible if one incoming is a gluon
     if(proc.njets >= 3 && subl_channels[subleading::eqqbar]){
       couple_parton.set(pid_to_index(HEJ::ParticleID::gluon));
     }
     if( // coupling possible through input
            allowed_partons[0] == (couple_parton&allowed_partons[0])
         || allowed_partons[1] == (couple_parton&allowed_partons[1])
         // cqqbar possible
         || (proc.njets >= 4 && subl_channels[subleading::cqqbar])
     ){
       return allowed_partons;
     }
     // only first can couple
     if( (allowed_partons[0]&couple_parton).any()
       &&(allowed_partons[1]&couple_parton).none()
     ){
       return {allowed_partons[0]&couple_parton, allowed_partons[1]};
     }
     // only second can couple
     if(  (allowed_partons[0]&couple_parton).none()
       && (allowed_partons[1]&couple_parton).any()
     ){
       return {allowed_partons[0], allowed_partons[1]&couple_parton};
     }
     // both can couple
     if(  (allowed_partons[0]&couple_parton).any()
       && (allowed_partons[1]&couple_parton).any()
     ){
       double rnd = ran.flat();
       weight_*=3.;
       if(rnd<1./3.){
         return {
           allowed_partons[0] & couple_parton,
           allowed_partons[1] & ~couple_parton
         };
       }
       if(rnd<2./3.){
         return {
           allowed_partons[0] & ~couple_parton,
           allowed_partons[1] & couple_parton
         };
       }
       return {
         allowed_partons[0] & couple_parton,
         allowed_partons[1] & couple_parton
       };
     }
     throw std::invalid_argument{"Incoming state not allowed."};
   }
 
   std::array<PhaseSpacePoint::part_mask,2> PhaseSpacePoint::incoming_eqqbar(
       std::array<part_mask,2> allowed_partons, HEJ::RNG & ran
   ){
     auto const gluon_idx = pid_to_index(HEJ::pid::gluon);
     auto & first_beam = allowed_partons[0];
     auto & second_beam = allowed_partons[1];
     if(first_beam[gluon_idx] && !second_beam[gluon_idx]){
       first_beam.reset();
       first_beam.set(gluon_idx);
       return allowed_partons;
     }
     if(!first_beam[gluon_idx] && second_beam[gluon_idx]) {
       second_beam.reset();
       second_beam.set(gluon_idx);
       return allowed_partons;
     }
     if(first_beam[gluon_idx] && second_beam[gluon_idx]) {
       // both beams can be gluons
       // if one can't be a quark everything is good
       auto first_quarks = first_beam;
       first_quarks.reset(gluon_idx);
       auto second_quarks = second_beam;
       second_quarks.reset(gluon_idx);
       if(first_quarks.none() || second_quarks.none()){
         return allowed_partons;
       }
       // else choose one to be a gluon
       double rnd = ran.flat();
       weight_*=3.;
       if(rnd<1./3.){
         allowed_partons[0].reset();
         allowed_partons[0].set(gluon_idx);
         allowed_partons[1].reset(gluon_idx);
       } else if(rnd<2./3.){
         allowed_partons[1].reset();
         allowed_partons[1].set(gluon_idx);
         allowed_partons[0].reset(gluon_idx);
       } else {
         allowed_partons[0].reset();
         allowed_partons[0].set(gluon_idx);
         allowed_partons[1].reset();
         allowed_partons[1].set(gluon_idx);
       }
       return allowed_partons;
     }
     throw std::invalid_argument{
       "Incoming state not allowed for pure extremal qqbar."};
   }
 
   std::array<PhaseSpacePoint::part_mask,2> PhaseSpacePoint::incoming_uno(
       std::array<part_mask,2> allowed_partons, HEJ::RNG & ran
   ){
     auto const gluon_idx = pid_to_index(HEJ::pid::gluon);
     auto & first_beam = allowed_partons[0];
     auto first_quarks = first_beam;
     first_quarks.reset(gluon_idx);
     auto & second_beam = allowed_partons[1];
     auto second_quarks = second_beam;
     second_quarks.reset(gluon_idx);
     if(first_quarks.any() && second_quarks.none()){
       first_beam.reset(gluon_idx);
       return allowed_partons;
     }
     if(first_quarks.none() && second_quarks.any()) {
       second_beam.reset(gluon_idx);
       return allowed_partons;
     }
      if(first_quarks.any() && second_quarks.any()) {
       // both beams can be quarks
       // if one can't be gluon everything is good
       if(!first_beam[gluon_idx] || !second_beam[gluon_idx]){
         return allowed_partons;
       }
       // else choose one to be a quark
       double rnd = ran.flat();
       weight_*=3.;
       if(rnd<1./3.){
         allowed_partons[0].reset(gluon_idx);
         allowed_partons[1].reset();
         allowed_partons[1].set(gluon_idx);
       } else if(rnd<2./3.){
         allowed_partons[1].reset(gluon_idx);
         allowed_partons[0].reset();
         allowed_partons[0].set(gluon_idx);
       } else {
         allowed_partons[0].reset(gluon_idx);
         allowed_partons[1].reset(gluon_idx);
       }
       return allowed_partons;
     }
     throw std::invalid_argument{
       "Incoming state not allowed for pure unordered."};
   }
 
   /**
    * @brief Returns list of all allowed initial states partons
    *
    * checks which partons are allowed as initial state:
    * 1. only allow what is given in the Runcard (p -> all)
    * 2. A/W/Z require something to couple to
    *  a) no qqbar => no incoming gluon
    *  b) 2j     => no incoming gluon
    *  c) >3j    => can couple OR is gluon => 2 gluons become qqbar later
    * 3. pure eqqbar requires at least one gluon
    * 4. pure uno requires at least one quark
    */
   std::array<PhaseSpacePoint::part_mask,2> PhaseSpacePoint::allowed_incoming(
       Process const & proc,
       double const subl_chance, Subleading const subl_channels,
       HEJ::RNG & ran
   ){
     // all possible incoming states
     std::array<part_mask,2> allowed_partons{
         init_allowed(proc.incoming[0]),
         init_allowed(proc.incoming[1])
       };
     // special case A/W/Z
     if(proc.boson && is_AWZ_proccess(proc)){
       allowed_partons = incoming_AWZ(proc, subl_channels, allowed_partons, ran);
     }
     // special case: pure subleading
     if(subl_chance!=1.){
       return allowed_partons;
     }
     auto other_channels = subl_channels;
     // pure eqqbar
     other_channels.reset(subleading::eqqbar);
     if(other_channels.none()){
       return incoming_eqqbar(allowed_partons, ran);
     }
     other_channels = subl_channels;
     // pure uno
     other_channels.reset(subleading::uno);
     if(other_channels.none()){
       return incoming_uno(allowed_partons, ran);
     }
     return allowed_partons;
   }
 
 
   void PhaseSpacePoint::reconstruct_incoming(
       Process const & proc,
       double const subl_chance, Subleading const subl_channels,
       HEJ::PDF & pdf, double E_beam,
       double uf,
       HEJ::RNG & ran
   ){
     std::tie(incoming_[0].p, incoming_[1].p) = incoming_momenta(outgoing_);
     // calculate xa, xb
     const double sqrts=2*E_beam;
     const double xa=(incoming_[0].E()-incoming_[0].pz())/sqrts;
     const double xb=(incoming_[1].E()+incoming_[1].pz())/sqrts;
     // abort if phase space point is outside of collider energy reach
     if (xa>1. || xb>1.){
       weight_=0;
       status_ = Status::too_much_energy;
       return;
     }
     auto const & ids = proc.incoming;
     std::array<part_mask,2> allowed_partons
       = allowed_incoming(proc, subl_chance, subl_channels, ran);
     for(size_t i = 0; i < 2; ++i){
       if(ids[i] == HEJ::pid::proton || ids[i] == HEJ::pid::p_bar){
       // pick ids according to pdfs
         incoming_[i].type =
           generate_incoming_id(i, i?xb:xa, uf, pdf, allowed_partons[i], ran);
       } else {
         assert(allowed_partons[i][pid_to_index(ids[i])]);
         incoming_[i].type = ids[i];
       }
     }
     assert(momentum_conserved(1e-7));
   }
 
   HEJ::ParticleID PhaseSpacePoint::generate_incoming_id(
       size_t const beam_idx, double const x, double const uf,
       HEJ::PDF & pdf, part_mask allowed_partons, HEJ::RNG & ran
   ){
     std::array<double,NUM_PARTONS> pdf_wt{};
     pdf_wt[0] = allowed_partons[0]?
       std::fabs(pdf.pdfpt(beam_idx,x,uf,HEJ::pid::gluon)):0.;
     double pdftot = pdf_wt[0];
     for(size_t i = 1; i < pdf_wt.size(); ++i){
       pdf_wt[i] = allowed_partons[i]?
         4./9.*std::fabs(pdf.pdfpt(beam_idx,x,uf,index_to_pid(i))):0;
       pdftot += pdf_wt[i];
     }
     const double r1 = pdftot * ran.flat();
     double sum = 0;
     for(size_t i=0; i < pdf_wt.size(); ++i){
       if (r1 < (sum+=pdf_wt[i])){
         weight_*= pdftot/pdf_wt[i];
         return index_to_pid(i);
       }
     }
     std::cerr << "Error in choosing incoming parton: "<<x<<" "<<uf<<" "
       <<sum<<" "<<pdftot<<" "<<r1<<std::endl;
     throw std::logic_error{"Failed to choose parton flavour"};
   }
 
   void PhaseSpacePoint::couple_boson(
     HEJ::ParticleID const boson, HEJ::RNG & ran
   ){
     if(std::abs(boson) != HEJ::pid::Wp) return; // only matters for W
     /// @TODO this could be use to sanity check gamma and Z
 
     // find all possible quarks
     std::vector<PartonIterator> allowed_parts;
     for(auto part_it=begin_partons(); part_it!=end_partons(); ++part_it){
       // Wp -> up OR anti-down, Wm -> anti-up OR down, no bottom
       if ( can_couple_to_W(*part_it, boson) )
         allowed_parts.push_back(part_it);
     }
     if(allowed_parts.empty()){
       throw std::logic_error{"Found no parton for coupling with boson"};
     }
 
     // select one and flip it
     size_t idx = 0;
     if(allowed_parts.size() > 1){
       /// @TODO more efficient sampling
       ///       old code: probability[i] = exp(parton[i].y - W.y)
       idx = std::floor(ran.flat()*allowed_parts.size());
       weight_ *= allowed_parts.size();
     }
     const int W_charge = boson>0?1:-1;
     allowed_parts[idx]->type =
       static_cast<HEJ::ParticleID>( allowed_parts[idx]->type - W_charge );
   }
 
   double PhaseSpacePoint::random_normal( double stddev, HEJ::RNG & ran ){
     const double r1 = ran.flat();
     const double r2 = ran.flat();
     const double lninvr1 = -std::log(r1);
     const double result = stddev*std::sqrt(2.*lninvr1)*std::cos(2.*M_PI*r2);
     weight_ *= exp(result*result/(2*stddev*stddev))*std::sqrt(2.*M_PI)*stddev;
     return result;
   }
 
   bool PhaseSpacePoint::momentum_conserved(double ep) const{
     fastjet::PseudoJet diff;
     for(auto const & in: incoming()) diff += in.p;
     for(auto const & out: outgoing()) diff -= out.p;
     return HEJ::nearby_ep(diff, fastjet::PseudoJet{}, ep);
   }
 
 } // namespace HEJFOG