Definition: Compose a new way to ask the same question. The new question must be asking the exact same thing as the original question does. Without any other information, you should be able to tell that the original question and the new question are the same. Preserve bracketed phrases in your new question. You can change the rest of the question provided the above requirements are satisfied. The new question must have a natural, fluent formulation, as if it were composed by a native English speaker. You will be given three pieces of information to help you create better questions. Those are: "Answer": the answer to the question, e.g., "Honolulu". "Answer Type": the type of the answer, e.g., "Location". "Auxiliary Information" is a detailed description of some concepts mentioned in the question, if any.
Input: original question: Which subatomic particle in the family of [Lepton] has smallest mass?
answer: electron
answer type: Subatomic particle.
auxiliary information: A lepton is an elementary, half-integer spin particle that does not undergo strong interactions, but is subject to the Pauli exclusion principle. The best known of all leptons is the electron, which is directly tied to all chemical properties. Two main classes of leptons exist: charged leptons, and neutral leptons. Charged leptons can combine with other particles to form various composite particles such as atoms and positronium, while neutrinos rarely interact with anything, and are consequently rarely observed. There are six types of leptons, known as flavours, forming three generations. The first generation is the electronic leptons, comprising the electron and electron neutrino; the second is the muonic leptons, comprising the muon and muon neutrino; and the third is the tauonic leptons, comprising the tau and the tau neutrino. Electrons have the least mass of all the charged leptons. The heavier muons and taus will rapidly change into electrons through a process of particle decay: the transformation from a higher mass state to a lower mass state.

Do you know what subatomic particle in the [Lepton] family has the smallest mass?