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diff --git a/doc/developer_manual/currents.tex b/doc/developer_manual/currents.tex
index 5756461..bdbae82 100644
--- a/doc/developer_manual/currents.tex
+++ b/doc/developer_manual/currents.tex
@@ -1,226 +1,229 @@
\section{Currents}
\label{sec:currents}
-In the following is a list of all the currents currently implemented in HEJ. All of them are defined inside \texttt{include/currents.hh}.
-
+The following section contains a list of all the currents implemented
+in \HEJ. Clean up of the code structure is ongoing. All W+Jet currents
+are located in \texttt{src/Wjets.cc}. All other currents are defined
+in \texttt{src/currents.cc}. There is a common header between these
+files located at \texttt{include/HEJ/currents.hh}.
\subsection{Pure Jets}
\subsubsection{Quark}
\label{sec:current_quark}
\begin{align}
j_\mu(p_i,p_j)=\bar{u}(p_i)\gamma_\mu u(p_j)
\end{align}
The exact for depends on the helicity and direction (forward/backwards) for the quarks. Currently all different contractions of incoming and outgoing states are defined in \lstinline!joi!, \lstinline!jio! and \lstinline!joo!.
\subsubsection{Gluon}
In \HEJ the currents for gluons and quarks are the same, up to a colour factor $K_g/C_F$, where
\begin{align}
K_g(p_1^-, p_a^-) = \frac{1}{2}\left(\frac{p_1^-}{p_a^-} + \frac{p_a^-}{p_1^-}\right)\left(C_A -
\frac{1}{C_A}\right)+\frac{1}{C_A}.
\end{align}
Thus we can just reuse the results from sec.~\ref{sec:current_quark}.
\subsubsection{Single unordered gluon}
Configuration $q(p_a) \to g(p_1) q(p_2) g^*(\tilde{q}_2)$~\cite{Andersen:2017kfc}
\begin{align}
\label{eq:juno}
\begin{split}
&j^{{\rm uno}\; \mu\ cd}(p_2,p_1,p_a) = i \varepsilon_{1\nu} \left( T_{2i}^{c}T_{ia}^d\
\left(U_1^{\mu\nu}-L^{\mu\nu} \right) + T_{2i}^{d}T_{ia}^c\ \left(U_2^{\mu\nu} +
L^{\mu\nu} \right) \right). \\
U_1^{\mu\nu} &= \frac1{s_{21}} \left( j_{21}^\nu j_{1a}^\mu + 2 p_2^\nu
j_{2a}^\mu \right) \qquad \qquad U_2^{\mu\nu} = \frac1{t_{a1}} \left( 2
j_{2a}^\mu p_a^\nu - j_{21}^\mu j_{1a}^\nu \right) \\
L^{\mu\nu} &= \frac1{t_{a2}} \left(-2p_1^\mu j_{2a}^\nu+2p_1.j_{2a}
g^{\mu\nu} + (\tilde{q}_1+\tilde{q}_2)^\nu j_{2a}^\mu + \frac{t_{b2}}{2} j_{2a}^\mu \left(
\frac{p_2^\nu}{p_1.p_2} + \frac{p_b^\nu}{p_1.p_b} \right) \right) ,
\end{split}
\end{align}
$j^{{\rm uno}\; \mu}$ is currently not calculated as a separate current, but always as needed for the ME (i.e. in \lstinline!jM2unoXXX!).
\subsection{Higgs}
Different rapidity orderings \todo{give name of functions}
\begin{enumerate}
\item $qQ\to HqQ/qHQ/qQH$ (any rapidity order, full LO ME) $\Rightarrow$ see~\ref{sec:V_H}
\item $qg\to Hqg$ (Higgs outside quark) $\Rightarrow$ see~\ref{sec:V_H}
\item $qg\to qHg$ (central Higgs) $\Rightarrow$ see~\ref{sec:V_H}
\item $qg\to qgH$ (Higgs outside gluon) $\Rightarrow$ see~\ref{sec:jH_mt}
\item $gg\to gHg$ (central Higgs) $\Rightarrow$ see~\ref{sec:V_H}
\item $gg\to ggH$ (Higgs outside gluon) $\Rightarrow$ see~\ref{sec:jH_mt}
\end{enumerate}
\subsubsection{Higgs gluon vertex}
\label{sec:V_H}
The coupling of the Higgs boson to gluons via a virtual quark loop can be written as
\begin{align}
\label{eq:VH}
V^{\mu\nu}_H(q_1, q_2) = \mathgraphics{build/figures/V_H.pdf} &=
\frac{\alpha_s m^2}{\pi v}\big[
g^{\mu\nu} T_1(q_1, q_2) - q_2^\mu q_1^\nu T_2(q_1, q_2)
\big]\, \\
&\xrightarrow{m \to \infty} \frac{\alpha_s}{3\pi
v} \left(g^{\mu\nu} q_1\cdot q_2 - q_2^\mu q_1^\nu\right).
\end{align}
The outgoing momentum of the Higgs boson is $p_H = q_1 - q_2$.
As a contraction with two currents this by implemented in \lstinline!cHdot! inside \texttt{src/currents.cc}.
The form factors $T_1$ and $T_2$ are then given by~\cite{DelDuca:2003ba}
\begin{align}
\label{eq:T_1}
T_1(q_1, q_2) ={}& -C_0(q_1, q_2)\*\left[2\*m^2+\frac{1}{2}\*\left(q_1^2+q_2^2-p_H^2\right)+\frac{2\*q_1^2\*q_2^2\*p_H^2}{\lambda}\right]\notag\\
&-\left[B_0(q_2)-B_0(p_H)\right]\*\frac{q_2^2}{\lambda}\*\left(q_2^2-q_1^2-p_H^2\right)\notag\\
&-\left[B_0(q_1)-B_0(p_H)\right]\*\frac{q_1^2}{\lambda}\*\left(q_1^2-q_2^2-p_H^2\right)-1\,,\displaybreak[0]\\
\label{eq:T_2}
T_2(q_1, q_2) ={}& C_0(q_1,
q_2)\*\left[\frac{4\*m^2}{\lambda}\*\left(p_H^2-q_1^2-q_2^2\right)-1-\frac{4\*q_1^2\*q_2^2}{\lambda}
-
\frac{12\*q_1^2\*q_2^2\*p_H^2}{\lambda^2}\*\left(q_1^2+q_2^2-p_H^2\right)\right]\notag\\
&-\left[B_0(q_2)-B_0(p_H)\right]\*\left[\frac{2\*q_2^2}{\lambda}+\frac{12\*q_1^2\*q_2^2}{\lambda^2}\*\left(q_2^2-q_1^2+p_H^2\right)\right]\notag\\
&-\left[B_0(q_1)-B_0(p_H)\right]\*\left[\frac{2\*q_1^2}{\lambda}+\frac{12\*q_1^2\*q_2^2}{\lambda^2}\*\left(q_1^2-q_2^2+p_H^2\right)\right]\notag\\
&-\frac{2}{\lambda}\*\left(q_1^2+q_2^2-p_H^2\right)\,,
\end{align}
where we have used the scalar bubble and triangle integrals
\begin{align}
\label{eq:B0}
B_0\left(p\right) ={}& \int \frac{d^dl}{i\pi^{\frac{d}{2}}}
\frac{1}{\left(l^2-m^2\right)\left((l+p)^2-m^2\right)}\,,\\
\label{eq:C0}
C_0\left(p,q\right) ={}& \int \frac{d^dl}{i\pi^{\frac{d}{2}}} \frac{1}{\left(l^2-m^2\right)\left((l+p)^2-m^2\right)\left((l+p-q)^2-m^2\right)}\,,
\end{align}
and the K\"{a}ll\'{e}n function
\begin{equation}
\label{eq:lambda}
\lambda = q_1^4 + q_2^4 + p_H^4 - 2\*q_1^2\*q_2^2 - 2\*q_1^2\*p_H^2- 2\*q_2^2\*p_H^2\,.
\end{equation}
The Integrals as such are provided by \QCDloop{} (see wrapper functions \lstinline!B0DD! and \lstinline!C0DD! in \texttt{src/currents.cc}).
In the code we are sticking to the convention of~\cite{DelDuca:2003ba}, thus instead of the $T_{1/2}$ we implement (in the functions \lstinline!A1! and \lstinline!A2!)
\begin{align}
\label{eq:A_1}
A_1(q_1, q_2) ={}& \frac{i}{16\pi^2}\*T_2(-q_1, q_2)\,,\\
\label{eq:A_2}
A_2(q_1, q_2) ={}& -\frac{i}{16\pi^2}\*T_1(-q_1, q_2)\,.
\end{align}
\subsubsection{Peripheral Higgs emission - Finite quark mass}
\label{sec:jH_mt}
We describe the emission of a peripheral Higgs boson close to a
scattering gluon with an effective current. In the following we consider
a lightcone decomposition of the gluon momenta, i.e. $p^\pm = E \pm p_z$
and $p_\perp = p_x + i p_y$. The incoming gluon momentum $p_a$ defines
the $-$ direction, so that $p_a^+ = p_{a\perp} = 0$. The outgoing
momenta are $p_1$ for the gluon and $p_H$ for the Higgs boson. We choose
the following polarisation vectors:
\begin{equation}
\label{eq:pol_vectors}
\epsilon_\mu^\pm(p_a) = \frac{j_\mu^\pm(p_1, p_a)}{\sqrt{2}
\bar{u}^\pm(p_a)u^\mp(p_1)}\,, \quad \epsilon_\mu^{\pm,*}(p_1) = -\frac{j_\mu^\pm(p_1, p_a)}{\sqrt{2}
\bar{u}^\mp(p_1)u^\pm(p_a)}\,.
\end{equation}
Following~\cite{DelDuca:2001fn}, we introduce effective polarisation
vectors to describe the contraction with the Higgs-boson production
vertex eq.~\eqref{eq:VH}:
\begin{align}
\label{eq:eps_H}
\epsilon_{H,\mu}(p_a) = \frac{T_2(p_a, p_a-p_H)}{(p_a-p_H)^2}\big[p_a\cdot
p_H\epsilon_\mu(p_a) - p_H\cdot\epsilon(p_a) p_{a,\mu}\big]\,,\\
\epsilon_{H,\mu}^*(p_1) = -\frac{T_2(p_1+p_H, p_1)}{(p_1+p_H)^2}\big[p_1\cdot
p_H\epsilon_\mu^*(p_1) - p_H\cdot\epsilon^*(p_1) p_{1,\mu}\big]\,,
\end{align}
We also employ the usual short-hand notation
\begin{equation}
\label{eq:spinor_helicity}
\spa i.j = \bar{u}^-(p_i)u^+(p_j)\,,\qquad \spb i.j =
\bar{u}^+(p_i)u^-(p_j)\,, \qquad[ i | H | j\rangle = j_\mu^+(p_i, p_j)p_H^\mu\,.
\end{equation}
Without loss of generality, we consider only the case where the incoming
gluon has positive helicity. The remaining helicity configurations can
be obtained through parity transformation.
Labelling the effective current by the helicities of the gluons we obtain
for the same-helicity case
\begin{equation}
\label{eq:jH_same_helicity}
\begin{split}
j_{H,\mu}^{++}{}&(p_1,p_a,p_H) =
\frac{m^2}{\pi v}\bigg[\\
&-\sqrt{\frac{2p_1^-}{p_a^-}}\frac{p_{1\perp}^*}{|p_{1\perp}|}\frac{t_2}{\spb a.1}\epsilon^{+,*}_{H,\mu}(p_1)
+\sqrt{\frac{2p_a^-}{p_1^-}}\frac{p_{1\perp}^*}{|p_{1\perp}|}\frac{t_2}{\spa 1.a}\epsilon^{+}_{H,\mu}(p_a)\\
&+ [1|H|a\rangle \bigg(
\frac{\sqrt{2}}{\spa 1.a}\epsilon^{+}_{H,\mu}(p_a)
+ \frac{\sqrt{2}}{\spb a.1}\epsilon^{+,*}_{H,\mu}(p_1)-\frac{\spa 1.a T_2(p_a, p_a-p_H)}{\sqrt{2}(p_a-p_H)^2}\epsilon^{+,*}_{\mu}(p_1)\\
&
\qquad
-\frac{\spb a.1 T_2(p_1+p_H,
p_1)}{\sqrt{2}(p_1+p_H)^2}\epsilon^{+}_{\mu}(p_a)-\frac{RH_4}{\sqrt{2}\spb a.1}\epsilon^{+,*}_{\mu}(p_1)+\frac{RH_5}{\sqrt{2}\spa 1.a}\epsilon^{+}_{\mu}(p_a)
\bigg)\\
&
- \frac{[1|H|a\rangle^2}{2 t_1}(p_{a,\mu} RH_{10} - p_{1,\mu} RH_{12})\bigg]
\end{split}
\end{equation}
with $t_1 = (p_a-p_1)^2$, $t_2 = (p_a-p_1-p_H)^2$ and $R = 8 \pi^2$. Eq.~\eqref{eq:jH_same_helicity}
is implemented by \lstinline!g_gH_HC! in \texttt{src/currents.cc}
\footnote{\lstinline!g_gH_HC! and \lstinline!g_gH_HNC! includes an additional
$1/t_2$ factor, which should be in the Matrix element instead.}.
The currents with a helicity flip is given through
\begin{equation}
\label{eq:jH_helicity_flip}
\begin{split}
j_{H,\mu}^{+-}{}&(p_1,p_a,p_H) =
\frac{m^2}{\pi v}\bigg[\\
&-\sqrt{\frac{2p_1^-}{p_a^-}}\frac{p_{1\perp}^*}{|p_{1\perp}|}\frac{t_2}{\spb
a.1}\epsilon^{-,*}_{H,\mu}(p_1)
+\sqrt{\frac{2p_a^-}{p_1^-}}\frac{p_{1\perp}}{|p_{1\perp}|}\frac{t_2}{\spb a.1}\epsilon^{+}_{H,\mu}(p_a)\\
&+ [1|H|a\rangle \left(
\frac{\sqrt{2}}{\spb a.1} \epsilon^{-,*}_{H,\mu}(p_1)
-\frac{\spa 1.a T_2(p_a, p_a-p_H)}{\sqrt{2}(p_a-p_H)^2}\epsilon^{-,*}_{\mu}(p_1)
- \frac{RH_4}{\sqrt{2}\spb a.1}\epsilon^{-,*}_{\mu}(p_1)\right)
\\
&+ [a|H|1\rangle \left(
\frac{\sqrt{2}}{\spb a.1}\epsilon^{+}_{H,\mu}(p_a)
-\frac{\spa 1.a
T_2(p_1+p_H,p_1)}{\sqrt{2}(p_1+p_H)^2}\epsilon^{+}_{\mu}(p_a)
+\frac{RH_5}{\sqrt{2}\spb a.1}\epsilon^{+}_{\mu}(p_a)
\right)\\
& - \frac{[1|H|a\rangle [a|H|1\rangle}{2 \spb a.1 ^2}(p_{a,\mu} RH_{10} - p_{1,\mu}
RH_{12})\\
&+ \frac{\spa 1.a}{\spb a.1}\bigg(RH_1p_{1,\mu}-RH_2p_{a,\mu}+2
p_1\cdot p_H \frac{T_2(p_1+p_H, p_1)}{(p_1+p_H)^2} p_{a,\mu}
\\
&
\qquad- 2p_a \cdot p_H \frac{T_2(p_a, p_a-p_H)}{(p_a-p_H)^2} p_{1,\mu}+ T_1(p_a-p_1, p_a-p_1-p_H)\frac{(p_1 + p_a)_\mu}{t_1}\\
&\qquad-\frac{(p_1+p_a)\cdot p_H}{t_1} T_2(p_a-p_1, p_a-p_1-p_H)(p_1 - p_a)_\mu
\bigg)
\bigg]\,,
\end{split}
\end{equation}
and implemented by \lstinline!g_gH_HNC! again in \texttt{src/currents.cc}.
If we instead choose the gluon momentum in the $+$ direction, so that
$p_a^- = p_{a\perp} = 0$, the corresponding currents are obtained by
replacing $p_1^- \to p_1^+, p_a^- \to p_a^+,
\frac{p_{1\perp}}{|p_{1\perp}|} \to -1$ in the second line of
eq.~\eqref{eq:jH_same_helicity} and eq.~\eqref{eq:jH_helicity_flip} (see variables \lstinline!ang1a! and \lstinline!sqa1! in the implementation).
The form factors $H_1,H_2,H_4,H_5, H_{10}, H_{12}$ are given in~\cite{DelDuca:2003ba}, and are implemented under their name in \texttt{src/currents.cc}. They reduce down to fundamental QCD integrals, which are again provided by \QCDloop.
\subsubsection{Peripheral Higgs emission - Infinite top mass}
\label{sec:jH_eff}
To get the result with infinite top mass we could either take the limit $m_t\to \infty$ in~\eqref{eq:jH_helicity_flip} and~\eqref{eq:jH_same_helicity}, or use the \textit{impact factors} as given in~\cite{DelDuca:2003ba}. Both methods are equivalent, and lead to the same result. For the first one would find
\begin{align}
\lim_{m_t\to\infty} m_t^2 H_1 &= i \frac{1}{24 \pi^2}\\
\lim_{m_t\to\infty} m_t^2 H_2 &=-i \frac{1}{24 \pi^2}\\
\lim_{m_t\to\infty} m_t^2 H_4 &= i \frac{1}{24 \pi^2}\\
\lim_{m_t\to\infty} m_t^2 H_5 &=-i \frac{1}{24 \pi^2}\\
\lim_{m_t\to\infty} m_t^2 H_{10} &= 0 \\
\lim_{m_t\to\infty} m_t^2 H_{12} &= 0.
\end{align}
\todo{double check this, see James thesis eq. 4.33}
However only the second method is implemented in the code through \lstinline!C2gHgp!
and \lstinline!C2gHgm! inside \texttt{src/currents.cc}, each function
calculates the square of eq. (4.23) and (4.22) from~\cite{DelDuca:2003ba} respectively.
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