If I have a reaction (shown below), and I'm supposed to work out what the products will be, what would the lepton neutrino $\nu$ be? e.g electron neutrino: $$ \nu + p \to $$
Put simply there is no unique answer, several possibilities are
including a whole host of meson production reactions. A colleague of mine is trying to extract lambda production cross-sections from a the data set of a test-bed liquid argon time-projection chamber for her dissertation even now.
Pay particular attnetion to the difference between options 2 and 3 or 4 and 5. The distinction between them is better exhibited at vertex level where they represent