why t3 , t8 plane ?

preet0283

in sampling about the flavor u,d,s ...we use the t3, t8 generators amd plot all the possible combinations of their eigen values ....and then define u ,d , s....
i want 2 ask that why specifically these 2 SU(3) generators are used t o
define flavors?
I have vague answers 2 this question but m not satisfied with those ....
plz help me !

Haelfix

You posed a bit of a vague question, you might want to reformulate it.

But I think the answer you are looking for is that that the up and down quark are much better symmetry partners (to a great approximation they are eigenstates of isospin symmetry, which the mass of the strange quark spontaneously breaks).

arivero

Why the "..."? For SU(3) flavour you can define u,d,s, and nothing more. If you want to build u,d,s,c you need SU(4) and so on. If you only want to use u,d you are happy with SU(2).

It seems sensible to choose generators (mesons) in a way that the inclusion SU(2) < SU(3) < SU(4) <... is explicit, but I am not sure if practicioners can use this rationale.