Question

particle X has a charge of -2e. reactions involving this particle has been known to produce byproducts like neutrons, protons and electrons.

how many possible ways could it decay into 2 particles? three particles? four particles? list the particle by products for each case and brieft explain your reasoning.

Answer 1

The two groups are called Fermions and Bosons

Fermions

Fermions are all particles that make up matter. The name comes from the fact that all particles of matter follow a certain set of laws called Fermi-Dirac Statistics, developed by Enrico Fermi and Paul Dirac in 1926.

All fermions in existence possess half integer spin i.e. 1/2, 3/2, 5/2 etc, for example every electron in the universe possesses a spin of 1/2. Fermions also obey the Pauli exclusion principle. This sounds complicated but it’s relatively simple to describe. What it means is that only certain combinations of matter can exist in the same space, more specifically it states that

No two identical fermions may occupy the same quantum state simultaneously

For example take Helium. It’s got a lowest energy shell for the electrons. You can put one electron in easy, however the Pauli Exclusion principle says 2 electrons can’t occupy the same quantum state so the second one has to have the opposite spin. This then allows the 2 electrons because spin is part of the quantum state of the electron, so the two electrons are occupying different quantum states. The spin however can only be one of two things, up or down (+1/2 or -1/2). If for example you had a lithium atom, which has three electrons then the third electron can’t fit into the 1st shell. So to fit it in it has to move up to the next shell. The entire Periodic table is built up from this principle.

There are two different types of fermions, Leptons and Quarks.

Leptons

There are six sub-atomic particles that make up the leptons; the Electron and the Electron Neutrino, the Muon and Muon Neutrino (which are basically heavier versions of the Electron and the Electron Neutrino), and the Tau and the Tau Neutrino (which are heavier versions still). The electron, muon and tau all have charges of -1 whereas all the neutrinos have charges of 0