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\title{\boldmath{ $\eta(1405)$}\ \ \ \ \ \ \ $***$}
\maketitle
The $\eta(1405)$ is one of a pair of $\eta$ resonances which was resolved in what had been called the $\eta(1440)$. It mainly decays to $a_0\pi$ and $\eta\pi\pi$ while the dominant decay of the heavier $\eta(1475)$ is to $K^*K$. The mass and width are measured with reasonable accuracy and we use the values from \cite{Yao:2006px}. The branching ratios are not measured and therefore we have used the measurement of the ratio
\begin{equation}
\frac{\Gamma(K^*K)}{\Gamma(a_0\pi)} = 0.084\pm0.024
\end{equation}
together with the assumption that the only modes are $K^*K$, $a_0\pi$ and $\eta\pi\pi$, where the pions are in an $s$-wave which we will model as the $\sigma$. We also assummed our branching ratios for the $a_0$ and that half the $\eta\pi\pi$ rate was due to the $a_0$. The $\eta(1405)$ is allowed to be off-shell by 10 times the width above the central value and 5 times below the central value to ensure the decay modes are kinematically allowed.
The $\eta(1405)$ has mass $1409.8$~MeV and is unstable. The $\eta(1405)$ has spin $0$, charge $0$ and is colour neutral.
 The $\eta(1405)$ is a mesonThe $\eta(1405)$ has width $51.1$~MeV. The lower limit on the mass of the particle is $255.5$~MeV and the upper limit is $511$~MeV. These are the deviations from the on-shell value. The branching ratios are fixed.
The properties of the particle and its antiparticle are taken to be charge-conjugate to each other.
 The PDG code is 9020221.
\setlongtables
\begin{longtable}[t]{|c|c|c|p{1in}|p{2.5in}|c|}
\hline
Branching & Rating & On/ & Outgoing  & Description & Decayer  \\ 
Ratio     &                                 & Off & Particles &             &         \\ 
\hline
\endhead
\caption{The decay modes of the $\eta(1405)$ (continues).}
\endfoot
\caption{The decay modes of the $\eta(1405)$.}
\endlastfoot
\label{tab:9020221decaymodes}
0.479845 & $***$ & on & $ \eta, \sigma $  & Decay of $\eta(1405)$ to the eta and a sigma with branching ratio calculated as described above.   & Herwig::ScalarScalarScalar::ScalarSS \\ 
\hline
0.159949 & $***$ & on & $ a^+_0(980), \pi^- $  & Decay of $\eta(1405)$ to $a_0$ and a pion with branching ratio calculated as described above.   & Herwig::ScalarScalarScalar::ScalarSS \\ 
\hline
0.159949 & $***$ & on & $ a^-_0(980), \pi^+ $  & Decay of $\eta(1405)$ to $a_0$ and a pion with branching ratio calculated as described above.   & Herwig::ScalarScalarScalar::ScalarSS \\ 
\hline
0.159949 & $***$ & on & $ a^0_0(980), \pi^0 $  & Decay of $\eta(1405)$ to $a_0$ and a pion with branching ratio calculated as described above.   & Herwig::ScalarScalarScalar::ScalarSS \\ 
\hline
0.010077 & $***$ & on & $ K^{*+}, K^- $  & Decay of $\eta(1405)$ to $K^*$ and a kaon with branching ratio calculated as described above.   & Herwig::PScalarPScalarVector::PPVDecayer \\ 
\hline
0.010077 & $***$ & on & $ K^{*-}, K^+ $  & Decay of $\eta(1405)$ to $K^*$ and a kaon with branching ratio calculated as described above.   & Herwig::PScalarPScalarVector::PPVDecayer \\ 
\hline
0.010077 & $***$ & on & $ \bar{K}^{*0}, K^0 $  & Decay of $\eta(1405)$ to $K^*$ and a kaon with branching ratio calculated as described above.   & Herwig::PScalarPScalarVector::PPVDecayer \\ 
\hline
0.010077 & $***$ & on & $ K^{*0}, \bar{K}^0 $  & Decay of $\eta(1405)$ to $K^*$ and a kaon with branching ratio calculated as described above.   & Herwig::PScalarPScalarVector::PPVDecayer \\ 
\hline
\end{longtable}The $\eta(1405)$ decay modes are given in Table~\ref{tab:9020221decaymodes} and the total branching ratio is $1$.


The mass generator is \verb|eta'''mass| for the $\eta(1405)$.
The width generator is \verb|eta(1405)width| for the $\eta(1405)$.

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 The particle was checked by Peter Richardson at 21:43:35 on the 20th of October 2007. The most recently changed decay mode was modified at 16:26:44 on the 2nd of August 2007. The particle data was last modified at 16:29:9 on the 2nd of August 2007.

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