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	diff --git a/include/RHEJ/JetSplitter.hh b/include/RHEJ/JetSplitter.hh
	new file mode 100644
	index 0000000..385870c
	--- /dev/null
	+++ b/include/RHEJ/JetSplitter.hh
	@@ -0,0 +1,57 @@
	+/**
	+ * \file
	+ * \brief Declaration of the JetSplitter class
	+ */
	+
	+#pragma once
	+
	+#include "RHEJ/utility.hh"
	+#include "RHEJ/RNG.hh"
	+
	+namespace RHEJ {
	+ //! Class to split jets into their constituents
	+ class JetSplitter {
	+
	+ public:
	+ struct SplitResult {
	+ std::vector<fastjet::PseudoJet> constituents;
	+ double weight;
	+ };
	+
	+ //! Constructor
	+ /**
	+ * @param jet_def Jet definition
	+ * @param min_pt Minimum jet transverse momentum
	+ * @param ran Random number generator
	+ */
	+ JetSplitter(
	+ fastjet::JetDefinition jet_def, double min_pt,
	+ RHEJ::RNG & ran
	+ ):
	+ R_{jet_def.R()},
	+ min_jet_pt_{min_pt},
	+ jet_def_{jet_def},
	+ ran_{ran}
	+ {}
	+
	+ //! Split a get into constituents
	+ /**
	+ * @param j2split Jet to be split
	+ * @param ncons Number of constituents
	+ * @returns The constituent momenta
	+ * together with the associated weight
	+ */
	+ SplitResult split(fastjet::PseudoJet const & j2split, int ncons) const;
	+
	+ //! Maximum distance of constituents to jet axis
	+ static constexpr double R_factor = 5./3.;
	+ private:
	+ SplitResult Split2(fastjet::PseudoJet const & j2split) const;
	+ double sample_distance_2p(double & wt) const;
	+
	+ double R_;
	+ double min_jet_pt_;
	+ fastjet::JetDefinition jet_def_;
	+ std::reference_wrapper<RHEJ::RNG> ran_;
	+ };
	+}
	diff --git a/include/RHEJ/PhaseSpacePoint.hh b/include/RHEJ/PhaseSpacePoint.hh
	index 7df62aa..03f3917 100644
	--- a/include/RHEJ/PhaseSpacePoint.hh
	+++ b/include/RHEJ/PhaseSpacePoint.hh
	@@ -1,149 +1,148 @@
	/** \file
	* \brief Contains the PhaseSpacePoint Class
	*/

	#pragma once

	#include <vector>

	#include "RHEJ/utility.hh"
	#include "RHEJ/config.hh"
	#include "RHEJ/Event.hh"
	-#include "RHEJ/Splitter.hh"
	+#include "RHEJ/JetSplitter.hh"
	#include "RHEJ/RNG.hh"

	namespace RHEJ{

	//! A point in resummation phase space
	class PhaseSpacePoint{
	public:
	//! Default PhaseSpacePoint Constructor
	PhaseSpacePoint() = default;

	//! PhaseSpacePoint Constructor
	/**
	* @param ev Clustered Jet Event
	* @param conf Configuration parameters
	* @param ran Random number generator
	*/
	PhaseSpacePoint(
	Event const & ev,
	PhaseSpacePointConfig conf,
	RHEJ::RNG & ran
	);

	//! Get phase space point weight
	double weight() const{
	return weight_;
	}

	//! Access incoming particles
	std::array<Particle, 2> const & incoming() const{
	return incoming_;
	}

	//! Access outgoing particles
	std::vector<Particle> const & outgoing() const{
	return outgoing_;
	}


	//! Particle decays
	/**
	* The key in the returned map corresponds to the index in the
	* vector returned by outgoing()
	*/
	std::unordered_map<int, std::vector<Particle>> const & decays() const{
	return decays_;
	}

	static constexpr int ng_max = 1000; //< maximum number of extra gluons

	private:

	std::vector<fastjet::PseudoJet> cluster_jets(
	std::vector<fastjet::PseudoJet> const & partons
	) const;
	bool pass_resummation_cuts(
	std::vector<fastjet::PseudoJet> const & jets
	) const;
	bool pass_extremal_cuts(
	fastjet::PseudoJet const & ext_parton,
	fastjet::PseudoJet const & jet
	) const;
	int sample_ng(std::vector<fastjet::PseudoJet> const & Born_jets);
	int sample_ng_jets(int ng, std::vector<fastjet::PseudoJet> const & Born_jets);
	double probability_in_jet(
	std::vector<fastjet::PseudoJet> const & Born_jets
	) const;
	std::vector<fastjet::PseudoJet> gen_non_jet(
	int ng_non_jet,
	double ptmin, double ptmax
	);
	void rescale_rapidities(
	std::vector<fastjet::PseudoJet> & partons,
	double ymin, double ymax
	);
	std::vector<fastjet::PseudoJet> reshuffle(
	std::vector<fastjet::PseudoJet> const & Born_jets,
	fastjet::PseudoJet const & q
	);
	bool jets_ok(
	std::vector<fastjet::PseudoJet> const & Born_jets,
	std::vector<fastjet::PseudoJet> const & partons
	) const;
	void reconstruct_incoming(std::array<Particle, 2> const & Born_incoming);
	double phase_space_normalisation(
	int num_Born_jets,
	int num_res_partons
	) const;
	std::vector<fastjet::PseudoJet> split(
	std::vector<fastjet::PseudoJet> const & jets, int ng_jets
	);
	std::vector<int> distribute_jet_partons(
	int ng_jets, std::vector<fastjet::PseudoJet> const & jets
	);
	std::vector<fastjet::PseudoJet> split(
	std::vector<fastjet::PseudoJet> const & jets,
	std::vector<int> const & np_in_jet
	);
	bool split_preserved_jets(
	std::vector<fastjet::PseudoJet> const & jets,
	std::vector<fastjet::PseudoJet> const & jet_partons
	) const;
	template<class Particle>
	Particle const & most_backward_FKL(
	std::vector<Particle> const & partons
	) const;
	template<class Particle>
	Particle const & most_forward_FKL(
	std::vector<Particle> const & partons
	) const;
	template<class Particle>
	Particle & most_backward_FKL(std::vector<Particle> & partons) const;
	template<class Particle>
	Particle & most_forward_FKL(std::vector<Particle> & partons) const;
	bool extremal_ok(
	std::vector<fastjet::PseudoJet> const & partons
	) const;
	void copy_AWZH_boson_from(Event const & event);

	bool momentum_conserved() const;

	bool unob_, unof_;

	double weight_;

	PhaseSpacePointConfig param_;


	std::array<Particle, 2> incoming_;
	std::vector<Particle> outgoing_;
	//! \internal Particle decays in the format {outgoing index, decay products}
	std::unordered_map<int, std::vector<Particle>> decays_;

	std::reference_wrapper<RHEJ::RNG> ran_;
	- HejSplit splitter_;
	};

	}
	diff --git a/include/RHEJ/Splitter.hh b/include/RHEJ/Splitter.hh
	deleted file mode 100644
	index 8e838b2..0000000
	--- a/include/RHEJ/Splitter.hh
	+++ /dev/null
	@@ -1,67 +0,0 @@
	-/**
	- * \file
	- * \brief Declaration of the HejSplit class
	- */
	-
	-#pragma once
	-
	-#include "RHEJ/utility.hh"
	-#include "RHEJ/RNG.hh"
	-
	-//! Class to split jets into their constituents
	-class HejSplit {
	-
	- public:
	- //! Constructor
	- /**
	- * @param rpin Jet radius parameter
	- * @param jetdefin Jet definition
	- * @param ptmin Minimum jet transverse momentum
	- * @param ran Random number generator
	- */
	- HejSplit(
	- double rpin, fastjet::JetDefinition jetdefin, double ptmin,
	- RHEJ::RNG & ran
	- ):
	- ran_{ran},
	- rp{rpin},
	- jetptmin{ptmin},
	- jet_def{jetdefin}
	- {}
	-
	- //! Split a get into constituents
	- /**
	- * @param j2split Jet to be split
	- * @param ncons Number of constituents
	- * @returns The weight factor associated with the split
	- */
	- double Split(fastjet::PseudoJet const & j2split, int ncons);
	- void PrintConstituentInfo(std::vector<fastjet::PseudoJet> jets);
	-
	- double getweight();
	- int gettrials();
	-
	- double get_qwt(){return qwt;}
	- double get_swt(){return swt;}
	-
	- //! Get constituents of the last split jet
	- std::vector<fastjet::PseudoJet> const & get_jcons() const{return jcons;}
	-
	- void clear_jcons(){jcons.clear();}
	- void reset_qwt(){qwt=1.;}
	- void reset_swt(){qwt=1.;}
	-
	- //! Maximum distance of constituents to jet axis
	- static constexpr double R_factor = 5./3.;
	- private:
	- double Split2(fastjet::PseudoJet const & j2split);
	- double sample_distance_2p(double & wt);
	-
	- std::reference_wrapper<RHEJ::RNG> ran_;
	- double rp;
	- double jetptmin;
	- fastjet::JetDefinition jet_def;
	- double qwt,swt;
	- std::vector<fastjet::PseudoJet> jcons;
	-
	-};
	diff --git a/src/JetSplitter.cc b/src/JetSplitter.cc
	new file mode 100644
	index 0000000..5ddc229
	--- /dev/null
	+++ b/src/JetSplitter.cc
	@@ -0,0 +1,174 @@
	+#include "RHEJ/JetSplitter.hh"
	+
	+#include <numeric>
	+
	+#include "RHEJ/Constants.hh"
	+#include "RHEJ/PhaseSpacePoint.hh"
	+
	+namespace RHEJ {
	+ namespace{
	+ constexpr double ccut=RHEJ::CMINPT; // min parton pt
	+
	+ template<class Iterator>
	+ bool same_pt_and_rapidity(
	+ Iterator begin, Iterator end,
	+ fastjet::PseudoJet const & jet
	+ ){
	+ static constexpr double ep = 1e-2;
	+ const fastjet::PseudoJet reconstructed_jet = std::accumulate(
	+ begin, end, fastjet::PseudoJet{}
	+ );
	+ return
	+ (std::abs(reconstructed_jet.pt() - jet.pt()) < ep)
	+ && (std::abs(reconstructed_jet.rapidity() - jet.rapidity()) < ep)
	+ ;
	+ }
	+
	+ bool all_in_one_jet(
	+ std::vector<fastjet::PseudoJet> const & partons,
	+ fastjet::JetDefinition jet_def, double min_jet_pt
	+ ){
	+ fastjet::ClusterSequence ev(partons, jet_def);
	+ const std::vector<fastjet::PseudoJet> testjet = ev.inclusive_jets(min_jet_pt);
	+ return testjet.size() == 1u
	+ && testjet[0].constituents().size() == partons.size();
	+ }
	+ }
	+
	+ using SplitResult = JetSplitter::SplitResult;
	+
	+ SplitResult JetSplitter::split(
	+ fastjet::PseudoJet const & j2split, int ncons
	+ ) const{
	+ if(ncons <= 0) {
	+ throw std::invalid_argument{
	+ "number of requested jet constituents less than 1"
	+ };
	+ }
	+ double swt = 1.;
	+
	+ std::vector<fastjet::PseudoJet> jcons;
	+ if(ncons == 1){
	+ jcons.emplace_back(j2split);
	+ jcons.back().set_user_index(0);
	+ return {jcons, swt};
	+ }
	+ if(ncons == 2){
	+ return Split2(j2split);
	+ }
	+ const double R_max = R_factor*R_;
	+ assert(R_max < M_PI);
	+
	+ double pt_remaining = j2split.pt();
	+ const double phi_jet = j2split.phi();
	+ const double y_jet = j2split.rapidity();
	+ for(int i = 0; i < ncons - 1; ++i){
	+ /**
	+ * Generate rapidity and azimuthal angle with a distance
	+ * R = sqrt(delta_y^2 + delta_phi^2) < R_max
	+ * from the jet centre
	+ */
	+ const double R = R_max*ran_.get().flat();
	+ const double theta = 2M_PIran_.get().flat();
	+ const double delta_phi = R*cos(theta);
	+ const double delta_y = R*sin(theta);
	+
	+ /**
	+ * Generate pt such that the total contribution of all partons
	+ * along the jet pt axis does not exceed the jet pt
	+ */
	+ const double pt_max = pt_remaining/cos(delta_phi);
	+ assert(pt_max > 0);
	+ if(pt_max < ccut) return {}; // no pt remaining for this parton
	+ const double pt = (pt_max - ccut)*ran_.get().flat() + ccut;
	+ pt_remaining -= pt*cos(delta_phi);
	+
	+ jcons.emplace_back(
	+ ptcos(phi_jet + delta_phi), ptsin(phi_jet + delta_phi),
	+ ptsinh(y_jet + delta_y), ptcosh(y_jet + delta_y)
	+ );
	+ jcons.back().set_user_index(i);
	+ swt = 2M_PIRR_maxpt(pt_max - ccut);
	+ }
	+
	+ const fastjet::PseudoJet p_total = std::accumulate(
	+ jcons.begin(), jcons.end(), fastjet::PseudoJet{}
	+ );
	+
	+ // Calculate the pt of the last parton
	+ const double last_px = j2split.px() - p_total.px();
	+ const double last_py = j2split.py() - p_total.py();
	+ const double last_pt = sqrt(last_pxlast_px + last_pylast_py);
	+ if(last_pt < ccut) return {};
	+
	+ // Calculate the rapidity of the last parton using the requirement that the
	+ // new jet must have the same rapidity as the LO jet.
	+ const double exp_2y_jet = (j2split.e() + j2split.pz())/(j2split.e() - j2split.pz());
	+ const double bb = (p_total.e()+p_total.pz()) - exp_2y_jet*(p_total.e()-p_total.pz());
	+ const double lasty = log((-bb+sqrt(bbbb+4.exp_2y_jetlast_ptlast_pt))/(2.*last_pt));
	+
	+ jcons.emplace_back(
	+ last_px, last_py, last_ptsinh(lasty), last_ptcosh(lasty)
	+ );
	+ jcons.back().set_user_index(ncons-1);
	+ assert(same_pt_and_rapidity(begin(jcons), end(jcons), j2split));
	+
	+ // Test that the last parton is not too far away from the jet centre.
	+ if (jcons.back().delta_R(j2split) > R_max) return {};
	+
	+ if(! all_in_one_jet(jcons, jet_def_, min_jet_pt_)) return {};
	+
	+ return {jcons, swt};
	+ }
	+
	+ //! sample y-phi distance to jet pt axis for a jet splitting into two partons
	+ /**
	+ * @param wt Multiplied by the weight of the sampling point
	+ * @returns The distance in units of the jet radius
	+ */
	+ double JetSplitter::sample_distance_2p(double & wt) const{
	+ static constexpr double x_small = 0.1;
	+ static constexpr double p_small = 0.4;
	+
	+ const double pR = ran_.get().flat();
	+ if(pR < p_small){
	+ wt *= x_small/p_small;
	+ return x_small/p_small*pR;
	+ }
	+ wt *= (1-x_small)/(1-p_small);
	+ return (1-x_small)/(1-p_small)*(pR-p_small) + x_small;
	+ }
	+
	+ // split jet into two partons
	+ SplitResult JetSplitter::Split2(fastjet::PseudoJet const & j2split) const{
	+ static constexpr size_t ncons = 2;
	+ std::vector<fastjet::PseudoJet> jcons(ncons);
	+ std::array<double, ncons> R, phi, y, pt;
	+ double wt = 1;
	+
	+ const double theta = 2M_PIran_.get().flat(); // angle in y-phi plane
	+ // empiric observation: we are always within the jet radius
	+ R[0] = sample_distance_2p(wt)*R_;
	+ R[1] = -sample_distance_2p(wt)*R_;
	+ for(size_t i = 0; i <= 1; ++i){
	+ phi[i] = j2split.phi() + R[i]*cos(theta);
	+ y[i] = j2split.rapidity() + R[i]*sin(theta);
	+ }
	+ for(size_t i = 0; i <= 1; ++i){
	+ pt[i] = (j2split.py() - tan(phi[1-i])*j2split.px())/
	+ (sin(phi[i]) - tan(phi[1-i])*cos(phi[i]));
	+ if(pt[i] < ccut) return {};
	+ jcons[i].reset_PtYPhiM(pt[i], y[i], phi[i]);
	+ jcons[i].set_user_index(i);
	+ }
	+ assert(same_pt_and_rapidity(begin(jcons), end(jcons), j2split));
	+
	+ if(! all_in_one_jet(jcons, jet_def_, min_jet_pt_)) return {};
	+ wt = 2M_PIpt[0]R[0]R_R_;
	+ // from transformation of delta(R[1] - ...) to delta(pt[0] - ...)
	+ const double dphi0 = phi[0] - j2split.phi();
	+ const double ptJ = j2split.pt();
	+ const double jacobian = cos(theta)pt[1]pt[1]/(ptJ*sin(dphi0));
	+ return {jcons, jacobian*wt};
	+ }
	+}
	diff --git a/src/PhaseSpacePoint.cc b/src/PhaseSpacePoint.cc
	index d63ed7c..3ac02ab 100644
	--- a/src/PhaseSpacePoint.cc
	+++ b/src/PhaseSpacePoint.cc
	@@ -1,535 +1,537 @@
	#include "RHEJ/PhaseSpacePoint.hh"

	#include <random>

	#include <CLHEP/Random/Randomize.h>
	#include <CLHEP/Random/RanluxEngine.h>

	#include "RHEJ/Constants.hh"
	#include "RHEJ/resummation_jet_momenta.hh"
	#include "RHEJ/Jacobian.hh"
	#include "RHEJ/uno.hh"
	#include "RHEJ/utility.hh"
	#include "RHEJ/kinematics.hh"

	namespace RHEJ{
	namespace {
	constexpr int max_jet_user_idx = PhaseSpacePoint::ng_max;

	bool is_nonjet_parton(fastjet::PseudoJet const & parton){
	assert(parton.user_index() != -1);
	return parton.user_index() > max_jet_user_idx;
	}

	bool is_jet_parton(fastjet::PseudoJet const & parton){
	assert(parton.user_index() != -1);
	return parton.user_index() <= max_jet_user_idx;
	}

	// user indices for partons with extremal rapidity
	constexpr int unob_idx = -5;
	constexpr int unof_idx = -4;
	constexpr int backward_FKL_idx = -3;
	constexpr int forward_FKL_idx = -2;
	}

	namespace {
	double estimate_ng_mean(std::vector<fastjet::PseudoJet> const & Born_jets){
	const double delta_y =
	Born_jets.back().rapidity() - Born_jets.front().rapidity();
	assert(delta_y > 0);
	// Formula derived from fit in reversed HEJ intro paper
	return 0.975052*delta_y;
	}
	}

	std::vector<fastjet::PseudoJet> PhaseSpacePoint::cluster_jets(
	std::vector<fastjet::PseudoJet> const & partons
	) const{
	fastjet::ClusterSequence cs(partons, param_.jet_param.def);
	return cs.inclusive_jets(param_.jet_param.min_pt);
	}

	bool PhaseSpacePoint::pass_resummation_cuts(
	std::vector<fastjet::PseudoJet> const & jets
	) const{
	return cluster_jets(jets).size() == jets.size();
	}

	int PhaseSpacePoint::sample_ng(std::vector<fastjet::PseudoJet> const & Born_jets){
	const double ng_mean = estimate_ng_mean(Born_jets);
	std::poisson_distribution<int> dist(ng_mean);
	const int ng = dist(ran_.get());
	assert(ng >= 0);
	assert(ng < ng_max);
	weight_ = std::tgamma(ng + 1)std::exp(ng_mean)*std::pow(ng_mean, -ng);
	return ng;
	}

	void PhaseSpacePoint::copy_AWZH_boson_from(Event const & event){
	auto const & from = event.outgoing();

	const auto AWZH_boson = std::find_if(
	begin(from), end(from),
	[](Particle const & p){ return is_AWZH_boson(p); }
	);
	if(AWZH_boson == end(from)) return;
	auto insertion_point = std::lower_bound(
	begin(outgoing_), end(outgoing_), *AWZH_boson, rapidity_less{}
	);
	outgoing_.insert(insertion_point, *AWZH_boson);

	// copy decay products
	const int idx = std::distance(begin(from), AWZH_boson);
	const auto decay_it = event.decays().find(idx);
	if(decay_it != end(event.decays())){
	const int new_idx = std::distance(begin(outgoing_), insertion_point);
	assert(outgoing_[new_idx].type == AWZH_boson->type);
	decays_.emplace(new_idx, decay_it->second);
	}

	assert(std::is_sorted(begin(outgoing_), end(outgoing_), rapidity_less{}));
	}

	PhaseSpacePoint::PhaseSpacePoint(
	Event const & ev, PhaseSpacePointConfig conf, RHEJ::RNG & ran
	):
	unob_{has_unob_gluon(ev.incoming(), ev.outgoing())},
	unof_{!unob_ && has_unof_gluon(ev.incoming(), ev.outgoing())},
	param_{std::move(conf)},
	- ran_{ran},
	- splitter_{param_.jet_param.def.R(), param_.jet_param.def, param_.jet_param.min_pt, ran}
	+ ran_{ran}
	{
	weight_ = 1;
	const auto Born_jets = sorted_by_rapidity(ev.jets());
	const int ng = sample_ng(Born_jets);
	weight_ /= std::tgamma(ng + 1);
	const int ng_jets = sample_ng_jets(ng, Born_jets);
	std::vector<fastjet::PseudoJet> out_partons = gen_non_jet(
	ng - ng_jets, CMINPT, param_.jet_param.min_pt
	);
	{
	const auto qperp = std::accumulate(
	begin(out_partons), end(out_partons),
	fastjet::PseudoJet{}
	);
	const auto jets = reshuffle(Born_jets, qperp);
	if(weight_ == 0.) return;
	if(! pass_resummation_cuts(jets)){
	weight_ = 0.;
	return;
	}
	std::vector<fastjet::PseudoJet> jet_partons = split(jets, ng_jets);
	if(weight_ == 0.) return;
	rescale_rapidities(
	out_partons,
	most_backward_FKL(jet_partons).rapidity(),
	most_forward_FKL(jet_partons).rapidity()
	);
	if(! cluster_jets(out_partons).empty()){
	weight_ = 0.;
	return;
	}
	std::sort(begin(out_partons), end(out_partons), rapidity_less{});
	assert(
	std::is_sorted(begin(jet_partons), end(jet_partons), rapidity_less{})
	);
	const auto first_jet_parton = out_partons.insert(
	end(out_partons), begin(jet_partons), end(jet_partons)
	);
	std::inplace_merge(
	begin(out_partons), first_jet_parton, end(out_partons), rapidity_less{}
	);
	}
	if(! jets_ok(Born_jets, out_partons)){
	weight_ = 0.;
	return;
	}
	weight_ *= phase_space_normalisation(Born_jets.size(), out_partons.size());

	outgoing_.reserve(out_partons.size() + 1); // one slot for possible A, W, Z, H
	for(auto & p: out_partons){
	outgoing_.emplace_back(Particle{pid::gluon, std::move(p)});
	}
	most_backward_FKL(outgoing_).type = ev.incoming().front().type;
	most_forward_FKL(outgoing_).type = ev.incoming().back().type;
	copy_AWZH_boson_from(ev);

	assert(!outgoing_.empty());
	reconstruct_incoming(ev.incoming());
	}

	std::vector<fastjet::PseudoJet> PhaseSpacePoint::gen_non_jet(
	int count, double ptmin, double ptmax
	){
	// heuristic parameters for pt sampling
	const double ptpar = 1.3 + count/5.;
	const double temp1 = atan((ptmax - ptmin)/ptpar);

	std::vector<fastjet::PseudoJet> partons(count);
	for(size_t i = 0; i < (size_t) count; ++i){
	const double r1 = ran_.get().flat();
	const double pt = ptmin + ptpartan(r1temp1);
	const double temp2 = cos(r1*temp1);
	const double phi = 2M_PIran_.get().flat();
	weight_ = 2.0M_PIptptpartemp1/(temp2temp2);
	// we don't know the allowed rapidity span yet,
	// set a random value to be rescaled later on
	const double y = ran_.get().flat();
	partons[i].reset_PtYPhiM(pt, y, phi);
	// Set user index higher than any jet-parton index
	// in order to assert that these are not inside jets
	partons[i].set_user_index(i + 1 + ng_max);

	assert(ptmin-1e-5 <= partons[i].pt() && partons[i].pt() <= ptmax+1e-5);
	}
	assert(std::all_of(partons.cbegin(), partons.cend(), is_nonjet_parton));
	return partons;
	}

	void PhaseSpacePoint::rescale_rapidities(
	std::vector<fastjet::PseudoJet> & partons,
	double ymin, double ymax
	){
	constexpr double ep = 1e-7;
	for(auto & parton: partons){
	assert(0 <= parton.rapidity() && parton.rapidity() <= 1);
	const double dy = ymax - ymin - 2*ep;
	const double y = ymin + ep + dy*parton.rapidity();
	parton.reset_momentum_PtYPhiM(parton.pt(), y, parton.phi());
	weight_ *= dy;
	assert(ymin <= parton.rapidity() && parton.rapidity() <= ymax);
	}
	}

	namespace {
	template<typename T, typename... Rest>
	auto min(T const & a, T const & b, Rest&&... r) {
	using std::min;
	return min(a, min(b, std::forward<Rest>(r)...));
	}
	}

	double PhaseSpacePoint::probability_in_jet(
	std::vector<fastjet::PseudoJet> const & Born_jets
	) const{
	assert(std::is_sorted(begin(Born_jets), end(Born_jets), rapidity_less{}));
	assert(Born_jets.size() >= 2);

	const double dy =
	Born_jets.back().rapidity() - Born_jets.front().rapidity();
	const double R = param_.jet_param.def.R();
	const int njets = Born_jets.size();
	const double p_J_y_large = (njets-1)RR/(2.*dy);
	const double p_J_y0 = njets*R/M_PI;
	return min(p_J_y_large, p_J_y0, 1.);
	}

	int PhaseSpacePoint::sample_ng_jets(
	int ng, std::vector<fastjet::PseudoJet> const & Born_jets
	){
	const double p_J = probability_in_jet(Born_jets);
	std::binomial_distribution<> bin_dist(ng, p_J);
	const int ng_J = bin_dist(ran_.get());
	weight_ = std::pow(p_J, -ng_J)std::pow(1 - p_J, ng_J - ng);
	return ng_J;
	}

	std::vector<fastjet::PseudoJet>
	PhaseSpacePoint::reshuffle(
	std::vector<fastjet::PseudoJet> const & Born_jets,
	fastjet::PseudoJet const & q
	){
	if(q == fastjet::PseudoJet{0, 0, 0, 0}) return Born_jets;
	std::vector<fastjet::PseudoJet> jets = resummation_jet_momenta(Born_jets, q);
	if(jets.empty()){
	weight_ = 0;
	return {};
	}
	// transform delta functions to integration over resummation momenta
	weight_ /= Jacobian(jets, q);
	return jets;
	}

	std::vector<int> PhaseSpacePoint::distribute_jet_partons(
	int ng_jets, std::vector<fastjet::PseudoJet> const & jets
	){
	size_t first_valid_jet = 0;
	size_t num_valid_jets = jets.size();
	const double R_eff = 5./3.*param_.jet_param.def.R();
	// if there is an unordered jet too far away from the FKL jets
	// then extra gluon constituents of the unordered jet would
	// violate the FKL rapidity ordering
	if(unob_ && jets[0].delta_R(jets[1]) > R_eff){
	++first_valid_jet;
	--num_valid_jets;
	}
	else if(unof_ && jets[jets.size()-1].delta_R(jets[jets.size()-2]) > R_eff){
	--num_valid_jets;
	}
	std::vector<int> np(jets.size(), 1);
	for(int i = 0; i < ng_jets; ++i){
	++np[first_valid_jet + ran_.get().flat() * num_valid_jets];
	}
	weight_ *= std::pow(num_valid_jets, ng_jets);
	return np;
	}

	#ifndef NDEBUG
	namespace{
	bool tagged_FKL_backward(
	std::vector<fastjet::PseudoJet> const & jet_partons
	){
	return std::find_if(
	begin(jet_partons), end(jet_partons),
	[](fastjet::PseudoJet const & p){
	return p.user_index() == backward_FKL_idx;
	}
	) != end(jet_partons);
	}

	bool tagged_FKL_forward(
	std::vector<fastjet::PseudoJet> const & jet_partons
	){
	// the most forward FKL parton is most likely near the end of jet_partons;
	// start search from there
	return std::find_if(
	jet_partons.rbegin(), jet_partons.rend(),
	[](fastjet::PseudoJet const & p){
	return p.user_index() == forward_FKL_idx;
	}
	) != jet_partons.rend();
	}

	bool tagged_FKL_extremal(
	std::vector<fastjet::PseudoJet> const & jet_partons
	){
	return tagged_FKL_backward(jet_partons) && tagged_FKL_forward(jet_partons);
	}

	} // namespace anonymous
	#endif

	std::vector<fastjet::PseudoJet> PhaseSpacePoint::split(
	std::vector<fastjet::PseudoJet> const & jets,
	int ng_jets
	){
	return split(jets, distribute_jet_partons(ng_jets, jets));
	}

	bool PhaseSpacePoint::pass_extremal_cuts(
	fastjet::PseudoJet const & ext_parton,
	fastjet::PseudoJet const & jet
	) const{
	if(ext_parton.pt() < param_.min_extparton_pt) return false;
	return (ext_parton - jet).pt()/jet.pt() < param_.max_ext_soft_pt_fraction;
	}

	std::vector<fastjet::PseudoJet> PhaseSpacePoint::split(
	std::vector<fastjet::PseudoJet> const & jets,
	std::vector<int> const & np
	){
	assert(! jets.empty());
	assert(jets.size() == np.size());
	assert(pass_resummation_cuts(jets));

	const size_t most_backward_FKL_idx = 0 + unob_;
	const size_t most_forward_FKL_idx = jets.size() - 1 - unof_;
	+ const auto & jet = param_.jet_param;
	+ const JetSplitter jet_splitter{jet.def, jet.min_pt, ran_};

	std::vector<fastjet::PseudoJet> jet_partons;
	// randomly distribute jet gluons among jets
	for(size_t i = 0; i < jets.size(); ++i){
	- weight_ *= splitter_.Split(jets[i], np[i]);
	+ auto split_res = jet_splitter.split(jets[i], np[i]);
	+ weight_ *= split_res.weight;
	if(weight_ == 0) return {};
	assert(
	std::all_of(
	- begin(splitter_.get_jcons()), end(splitter_.get_jcons()),
	+ begin(split_res.constituents), end(split_res.constituents),
	is_jet_parton
	)
	);
	const auto first_new_parton = jet_partons.insert(
	end(jet_partons),
	- begin(splitter_.get_jcons()), end(splitter_.get_jcons())
	+ begin(split_res.constituents), end(split_res.constituents)
	);
	// mark uno and extremal FKL emissions here so we can check
	// their position once all emissions are generated
	auto extremal = end(jet_partons);
	if((unob_ && i == 0) \|\| i == most_backward_FKL_idx){
	// unordered or FKL backward emission
	extremal = std::min_element(
	first_new_parton, end(jet_partons), rapidity_less{}
	);
	extremal->set_user_index(
	(i == most_backward_FKL_idx)?backward_FKL_idx:unob_idx
	);
	}
	else if((unof_ && i == jets.size() - 1) \|\| i == most_forward_FKL_idx){
	// unordered or FKL forward emission
	extremal = std::max_element(
	first_new_parton, end(jet_partons), rapidity_less{}
	);
	extremal->set_user_index(
	(i == most_forward_FKL_idx)?forward_FKL_idx:unof_idx
	);
	}
	if(
	extremal != end(jet_partons)
	&& !pass_extremal_cuts(*extremal, jets[i])
	){
	weight_ = 0;
	return {};
	}
	}
	assert(tagged_FKL_extremal(jet_partons));
	std::sort(begin(jet_partons), end(jet_partons), rapidity_less{});
	if(
	!extremal_ok(jet_partons)
	\|\| !split_preserved_jets(jets, jet_partons)
	){
	weight_ = 0.;
	return {};
	}
	return jet_partons;
	}

	bool PhaseSpacePoint::extremal_ok(
	std::vector<fastjet::PseudoJet> const & partons
	) const{
	assert(std::is_sorted(begin(partons), end(partons), rapidity_less{}));
	if(unob_ && partons.front().user_index() != unob_idx) return false;
	if(unof_ && partons.back().user_index() != unof_idx) return false;
	return
	most_backward_FKL(partons).user_index() == backward_FKL_idx
	&& most_forward_FKL(partons).user_index() == forward_FKL_idx;
	}

	bool PhaseSpacePoint::split_preserved_jets(
	std::vector<fastjet::PseudoJet> const & jets,
	std::vector<fastjet::PseudoJet> const & jet_partons
	) const{
	assert(std::is_sorted(begin(jets), end(jets), rapidity_less{}));

	const auto split_jets = sorted_by_rapidity(cluster_jets(jet_partons));
	// this can happen if two overlapping jets
	// are both split into more than one parton
	if(split_jets.size() != jets.size()) return false;
	for(size_t i = 0; i < split_jets.size(); ++i){
	// this can happen if there are two overlapping jets
	// and a parton is assigned to the "wrong" jet
	if(!nearby_ep(jets[i].rapidity(), split_jets[i].rapidity(), 1e-2)){
	return false;
	}
	}
	return true;
	}

	template<class Particle>
	Particle const & PhaseSpacePoint::most_backward_FKL(
	std::vector<Particle> const & partons
	) const{
	return partons[0 + unob_];
	}

	template<class Particle>
	Particle const & PhaseSpacePoint::most_forward_FKL(
	std::vector<Particle> const & partons
	) const{
	const size_t idx = partons.size() - 1 - unof_;
	assert(idx < partons.size());
	return partons[idx];
	}

	template<class Particle>
	Particle & PhaseSpacePoint::most_backward_FKL(
	std::vector<Particle> & partons
	) const{
	return partons[0 + unob_];
	}

	template<class Particle>
	Particle & PhaseSpacePoint::most_forward_FKL(
	std::vector<Particle> & partons
	) const{
	const size_t idx = partons.size() - 1 - unof_;
	assert(idx < partons.size());
	return partons[idx];
	}

	namespace {
	bool contains_idx(
	fastjet::PseudoJet const & jet, fastjet::PseudoJet const & parton
	){
	auto const & constituents = jet.constituents();
	const int idx = parton.user_index();
	return std::find_if(
	begin(constituents), end(constituents),
	[idx](fastjet::PseudoJet const & con){return con.user_index() == idx;}
	) != end(constituents);
	}
	}

	/**
	* final jet test:
	* - number of jets must match Born kinematics
	* - no partons designated as nonjet may end up inside jets
	* - all other outgoing partons must end up inside jets
	* - the extremal (in rapidity) partons must be inside the extremal jets
	* - rapidities must be the same (by construction)
	*/
	bool PhaseSpacePoint::jets_ok(
	std::vector<fastjet::PseudoJet> const & Born_jets,
	std::vector<fastjet::PseudoJet> const & partons
	) const{
	fastjet::ClusterSequence cs(partons, param_.jet_param.def);
	const auto jets = sorted_by_rapidity(cs.inclusive_jets(param_.jet_param.min_pt));
	if(jets.size() != Born_jets.size()) return false;
	int in_jet = 0;
	for(size_t i = 0; i < jets.size(); ++i){
	assert(jets[i].has_constituents());
	for(auto && parton: jets[i].constituents()){
	if(is_nonjet_parton(parton)) return false;
	}
	in_jet += jets[i].constituents().size();
	}
	const int expect_in_jet = std::count_if(
	partons.cbegin(), partons.cend(), is_jet_parton
	);
	if(in_jet != expect_in_jet) return false;
	// note that PseudoJet::contains does not work here
	if(! (
	contains_idx(most_backward_FKL(jets), most_backward_FKL(partons))
	&& contains_idx(most_forward_FKL(jets), most_forward_FKL(partons))
	)) return false;
	if(unob_ && !contains_idx(jets.front(), partons.front())) return false;
	if(unof_ && !contains_idx(jets.back(), partons.back())) return false;
	for(size_t i = 0; i < jets.size(); ++i){
	assert(nearby_ep(jets[i].rapidity(), Born_jets[i].rapidity(), 1e-2));
	}
	return true;
	}

	void PhaseSpacePoint::reconstruct_incoming(
	std::array<Particle, 2> const & Born_incoming
	){
	std::tie(incoming_[0].p, incoming_[1].p) = incoming_momenta(outgoing_);
	for(size_t i = 0; i < incoming_.size(); ++i){
	incoming_[i].type = Born_incoming[i].type;
	}
	assert(momentum_conserved());
	}

	double PhaseSpacePoint::phase_space_normalisation(
	int num_Born_jets, int num_out_partons
	) const{
	return pow(16*pow(M_PI,3), num_Born_jets - num_out_partons);
	}

	bool PhaseSpacePoint::momentum_conserved() const{
	fastjet::PseudoJet diff;
	for(auto const & in: incoming()) diff += in.p;
	const double norm = diff.E();
	for(auto const & out: outgoing()) diff -= out.p;
	return nearby(diff, fastjet::PseudoJet{}, norm);
	}

	} //namespace RHEJ
	diff --git a/src/Splitter.cc b/src/Splitter.cc
	deleted file mode 100644
	index 73e4cf7..0000000
	--- a/src/Splitter.cc
	+++ /dev/null
	@@ -1,211 +0,0 @@
	-/**
	- * Name: splitter.cc
	- * Author: Tuomas Hapola
	- *
	- * double Sample2jetPartons(int * np);
	- * bool Split(fastjet::PseudoJet j2split, int ncons);
	- * bool DistributeQperp(fastjet::PseudoJet qperp, int np, double miny, double maxy);
	- * void PrintConstituentInfo(std::vector<fastjet::PseudoJet> jets);
	- *
	- */
	-
	-#include <numeric>
	-
	-#include "RHEJ/Constants.hh"
	-#include "RHEJ/Splitter.hh"
	-#include "RHEJ/PhaseSpacePoint.hh"
	-
	-namespace{
	- constexpr double ccut=RHEJ::CMINPT; // min parton pt
	-
	- template<class Iterator>
	- bool same_pt_and_rapidity(
	- Iterator begin, Iterator end,
	- fastjet::PseudoJet const & jet
	- ){
	- static constexpr double ep = 1e-2;
	- const fastjet::PseudoJet reconstructed_jet = std::accumulate(
	- begin, end, fastjet::PseudoJet{}
	- );
	- return
	- (std::abs(reconstructed_jet.pt() - jet.pt()) < ep)
	- && (std::abs(reconstructed_jet.rapidity() - jet.rapidity()) < ep)
	- ;
	- }
	-
	- bool all_in_one_jet(
	- std::vector<fastjet::PseudoJet> const & partons,
	- fastjet::JetDefinition jet_def, double min_jet_pt
	- ){
	- fastjet::ClusterSequence ev(partons, jet_def);
	- const std::vector<fastjet::PseudoJet> testjet = ev.inclusive_jets(min_jet_pt);
	- return testjet.size() == 1u
	- && testjet[0].constituents().size() == partons.size();
	- }
	-}
	-
	-double HejSplit::Split(fastjet::PseudoJet const & j2split, int ncons){
	- assert(ncons >= 1);
	-
	- double swt = 1.;
	-
	- jcons.clear();
	- jcons.reserve(ncons);
	- if(ncons == 1){
	- jcons.emplace_back(j2split);
	- jcons.back().set_user_index(0);
	- return swt;
	- }
	- if(ncons == 2){
	- return Split2(j2split);
	- }
	- const double R_max = R_factor*rp;
	- assert(R_max < M_PI);
	-
	- double pt_remaining = j2split.pt();
	- const double phi_jet = j2split.phi();
	- const double y_jet = j2split.rapidity();
	- for(int i = 0; i < ncons - 1; ++i){
	- /**
	- * Generate rapidity and azimuthal angle with a distance
	- * R = sqrt(delta_y^2 + delta_phi^2) < R_max
	- * from the jet centre
	- */
	- const double R = R_max*ran_.get().flat();
	- const double theta = 2M_PIran_.get().flat();
	- const double delta_phi = R*cos(theta);
	- const double delta_y = R*sin(theta);
	-
	- /**
	- * Generate pt such that the total contribution of all partons
	- * along the jet pt axis does not exceed the jet pt
	- */
	- const double pt_max = pt_remaining/cos(delta_phi);
	- assert(pt_max > 0);
	- if(pt_max < ccut) return false; // no pt remaining for this parton
	- const double pt = (pt_max - ccut)*ran_.get().flat() + ccut;
	- pt_remaining -= pt*cos(delta_phi);
	-
	- jcons.emplace_back(
	- ptcos(phi_jet + delta_phi), ptsin(phi_jet + delta_phi),
	- ptsinh(y_jet + delta_y), ptcosh(y_jet + delta_y)
	- );
	- jcons.back().set_user_index(i);
	- swt = 2M_PIRR_maxpt(pt_max - ccut);
	- }
	-
	- const fastjet::PseudoJet p_total = std::accumulate(
	- jcons.begin(), jcons.end(), fastjet::PseudoJet{}
	- );
	-
	- // Calculate the pt of the last parton
	- const double last_px = j2split.px() - p_total.px();
	- const double last_py = j2split.py() - p_total.py();
	- const double last_pt = sqrt(last_pxlast_px + last_pylast_py);
	- if(last_pt < ccut) return 0.;
	-
	- // Calculate the rapidity of the last parton using the requirement that the
	- // new jet must have the same rapidity as the LO jet.
	- const double exp_2y_jet = (j2split.e() + j2split.pz())/(j2split.e() - j2split.pz());
	- const double bb = (p_total.e()+p_total.pz()) - exp_2y_jet*(p_total.e()-p_total.pz());
	- const double lasty = log((-bb+sqrt(bbbb+4.exp_2y_jetlast_ptlast_pt))/(2.*last_pt));
	-
	- jcons.emplace_back(
	- last_px, last_py, last_ptsinh(lasty), last_ptcosh(lasty)
	- );
	- jcons.back().set_user_index(ncons-1);
	- assert(same_pt_and_rapidity(begin(jcons), end(jcons), j2split));
	-
	- // Test that the last parton is not too far away from the jet centre.
	- if (jcons.back().delta_R(j2split) > R_max) return 0.;
	-
	- if(! all_in_one_jet(jcons, jet_def, jetptmin)) return 0.;
	-
	- return swt;
	-}
	-
	-//! sample y-phi distance to jet pt axis for a jet splitting into two partons
	-/**
	- * @param wt Multiplied by the weight of the sampling point
	- * @returns The distance in units of the jet radius
	- */
	-double HejSplit::sample_distance_2p(double & wt){
	- static constexpr double x_small = 0.1;
	- static constexpr double p_small = 0.4;
	-
	- const double pR = ran_.get().flat();
	- if(pR < p_small){
	- wt *= x_small/p_small;
	- return x_small/p_small*pR;
	- }
	- wt *= (1-x_small)/(1-p_small);
	- return (1-x_small)/(1-p_small)*(pR-p_small) + x_small;
	-}
	-
	-// split jet into two partons
	-double HejSplit::Split2(fastjet::PseudoJet const & j2split){
	- static constexpr size_t ncons = 2;
	- jcons.resize(ncons);
	- std::array<double, ncons> R, phi, y, pt;
	- double wt = 1;
	-
	- const double theta = 2M_PIran_.get().flat(); // angle in y-phi plane
	- // empiric observation: we are always within the jet radius
	- R[0] = sample_distance_2p(wt)*rp;
	- R[1] = -sample_distance_2p(wt)*rp;
	- for(size_t i = 0; i <= 1; ++i){
	- phi[i] = j2split.phi() + R[i]*cos(theta);
	- y[i] = j2split.rapidity() + R[i]*sin(theta);
	- }
	- for(size_t i = 0; i <= 1; ++i){
	- pt[i] = (j2split.py() - tan(phi[1-i])*j2split.px())/
	- (sin(phi[i]) - tan(phi[1-i])*cos(phi[i]));
	- if(pt[i] < ccut) return 0.;
	- jcons[i].reset_PtYPhiM(pt[i], y[i], phi[i]);
	- jcons[i].set_user_index(i);
	- }
	- assert(same_pt_and_rapidity(begin(jcons), end(jcons), j2split));
	-
	- if(! all_in_one_jet(jcons, jet_def, jetptmin)) return 0.;
	- wt = 2M_PIpt[0]R[0]rprp;
	- // from transformation of delta(R[1] - ...) to delta(pt[0] - ...)
	- const double dphi0 = phi[0] - j2split.phi();
	- const double ptJ = j2split.pt();
	- const double jacobian = cos(theta)pt[1]pt[1]/(ptJ*sin(dphi0));
	- return jacobian*wt;
	-}
	-
	-
	-void HejSplit::PrintConstituentInfo(std::vector<fastjet::PseudoJet> jets){
	-
	- // tell the user what was done
	- // - the description of the algorithm used
	- // - extract the inclusive jets with pt > 5 GeV
	- // show the output as
	- // {index, rap, phi, pt, number of constituents}
	- //----------------------------------------------------------
	- std::cout << "Ran " << (jet_def).description() << std::endl << std::endl;
	-
	- // label the columns
	- printf("%5s %15s %15s %15s %15s\n","jet #", "rapidity", "phi", "pt", "n constituents");
	- printf(" indices of constituents\n\n");
	- //njj[jets.size()] += 1;
	- // print out the details for each jet
	- for (unsigned int i = 0; i < jets.size(); i++) {
	- // get the constituents of the jet
	- std::vector<fastjet::PseudoJet> constituents = jets[i].constituents();
	- //nco[jets.size()] += int(constituents.size());
	- //if (int(constituents.size())>maxco)
	- //maxco = int(constituents.size());
	- printf("%5u %15.8f %15.8f %15.8f %8u\n",
	- i, jets[i].rap(), jets[i].phi(),
	- jets[i].perp(), (unsigned int) constituents.size());
	-
	- printf(" ");
	- for (unsigned int j=0; j<constituents.size(); j++){
	- printf("%4u ", constituents[j].user_index());
	- if (j%10==9) printf("\n ");
	- }
	- printf("\n\n");
	- }
	-}

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