When a ${\pi }^{-}$ decays, the products may include: (a) A positron
(b) A muon
(c) A proton
(d) All of the above

Video Transcript

This is College Physics Answers with Shaun Dychko. When a negative pion decays, the products have to include something that has a negative charge in order for charge conservation to apply and charge conservation is one of these strong conservation or exact conservation rules; exact meaning there are no exceptions to it. So if this negative thing decays, it has to produce a negative thing and so that means a muon, which is negatively charged could be one of the products.