A typically complex high-energy interaction produced by a neutrino

Before it was posible to study neutrino events with a bubble chamber, there was some speculation as to whether neutrinos would produce other than simple interactions of the type $\nu + \eta \rightarrow \mu^{-} +p$. The figure shows a typically complex high-energy interaction produced by a neutrino. It is evident that several pions are produced possibly a Dalitz pair (the uppermost trace is one electron, gamma-rays nearby perhaps come from the positron). One wonders at what stage in the experimental study of neutino phenomena the mechanism of such an event will be understood. The print has been made with a double impression to give an illusion of the three dimensions in which the event can be seen in reality in the bubble chamber.