On Jan 27, 11:53*am, PD wrote:

And how does a quark turn into a lepton? Is that in the Standard Model?

It comes from one of several *extensions* to the Standard Model.
Examples include the now defunct SU(5) supergroup, technicolor, and
some supersymmetry variants.

Please read the preceding posts. It _is_ Standard Model, albeit many
people (including me, until now) have never heard of it.

Andrew Usher