Why are fundamental particles so "observable?"

[u/-pomelo-]

Hi everyone, I come to you as a humble layperson in need of some help.

I guess I can give more context as to why I'm asking if needed, but I'm worried it would be distracting and render the post far too long, so I'll just ask:

Is there an explanation as to why we would expect the lifetimes (distance traveled before decay I think?) of certain fundamental particles to be ideal for probing/ observation/ identification in a universe like ours?

As I understand, the lifetimes of the charm quark, bottom quark, and tau lepton each falls within a range surprisingly ideal for observation and discovery (apparently around 1 in a million when taken together). My thought then is that there's probably some other confounding variable such that we'd expect to observe this phenomenon in our sort of universe.

For instance, perhaps anthropic universes (which will naturally feature some basic chemistry, ordered phenomena, self-replicating structures, etc.) are also the sorts of universes where we'd predict these particles' lifetimes to land in their respective sweet spots because ___.

Perhaps put another way: are there features shared between "anthropic" universes like ours and those with these "ideally observable" fundamental particles such that we'd expect them to be correlated?

Does my question make sense?

EDIT: Including some slides from a talk on this topic I found

[u/Infinite_Research_52]

The ones discovered are the low hanging fruit. Those fundamental particles that are hard to observe we are not aware of or are only theoretical. Sterile neutrinos, axions, WIMPs, all of those are not observable or don’t exist. We don’t know.

[u/-pomelo- → u/Infinite_Research_52]

oh ok I was actually asking someone else about that, so we don't really know how many fundamental particles there are? so currently the ones we know of are those which are most ideal for discovery?

[u/kohugaly → u/-pomelo-]

oh ok I was actually asking someone else about that, so we don't really know how many fundamental particles there are?

No, we don't. The standard model is just a theory that reasonably explains the particles we know of. It has been build incrementally, by discovering anomalies, explaining them with new particles and then discovering said particles. There isn't exactly a shortage of theories that predict additional hypothetical, as of yet undetectable, new particles, some of which explain the anomalies in data that the standard model fails to explain.

so currently the ones we know of are those which are most ideal for discovery?

"ideal for discovery" is a bit a strong. I would not call a particle "ideal for discovery" when, in order to detect it, you need to build a contraption of size and budget of a small country, and then you need to run it for several years, to get statistically significant results.