Standard Model – Comprehensive Guide to Elementary Particle Properties

elementary-particlesstandard-model

Basic question about the Standard Model: Is it accurate to say that all of the particles defined by the SM can be categorically distinguished entirely by discrete properties (eg, spin, color, charge units, interaction type, etc), as opposed to also requiring continuous properties (eg, rest mass, etc)? I'm wondering if the discrete/continuous property distinction somehow reflects a fundamental distinction between quantum and classical "objects".

Best Answer

Is it accurate to say that all of the particles defined by the SM ...

The standard model is a quantum field theoretical model. The elementary particles of the standard model are axiomatic, they are not defined by the model, but constrain the model:

elempart

There is nothing continuous in the definitions in the table, the particles are also, for the model, point particles, they have no extent in space.

Over the years the table has been expanded as more and more particles were found necessary in order to fit the data, and as accelerators open up higher mass possibilities this will probably go on, as the theoretical model will be expanding to fit the newer data.

Related Question