100 ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ 2 ${{\mathit \eta}}$ X
References:
ALDE
1986D
NP B269 485
Production of ${{\mathit G}{(1590)}}$ and other Mesons Decaying into ${{\mathit \eta}}$ Pairs by 100 ${\mathrm {GeV/}}\mathit c$ ${{\mathit \pi}^{-}}$ on Protons
