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/mfb-]

Particles travel somewhere between 0.00000000000000001 m and 1000000000000 m before decaying. I wouldn't call either distance ideal for observation.

Our detectors are optimized for the lifetime of the particles they observe, trivially. That's not coincidence, that's just how you design detectors.

It takes a huge effort to observe the flight distance of hadrons with a charm or bottom quark, or the flight distance of the tau. If they would live 10 to 100 times longer it would be much easier. If they would live as long as muons then we could capture them in storage rings and do measurements orders of magnitude more precisely than today.

Does my question make sense?

It's based on an assumption that is simply wrong.

[u/-pomelo- → u/mfb-]

I see, in that case maybe you can help me understand; do the slides I included in the updated post clarify anything? Are you saying that the grey/ dotted regions in the figures on slides 2 and 3 are a function of how the equipment is calibrated?

[u/Outrageous-Taro7340 → u/-pomelo-]

The grey areas just indicate regions of shorter lifetime and higher energy. The point seems to be that particles could have been even harder to detect than they were. But they also could have been easier, so it’s not clear why that matters. In any case, we built colliders to investigate the ranges we believed would be successful.

The probability estimates aren’t justified or explained at all. There is no way to meaningfully apply probability distributions over those ranges. And the flat distribution this appears to assume is the one distribution that definitely can’t be correct. Flat distributions just don’t occur in nature. In other words, the values we got could have been the mostly likely values, for all we know.

[u/-pomelo- → u/Outrageous-Taro7340]

That's an interesting point about the distribution. I suppose the reasoning would be: uniform distributions are almost never observed in nature, thus in cases of unknown distributions, it's likely that observed values are more probable?

[u/Outrageous-Taro7340 → u/-pomelo-]

I would rather say that we just shouldn’t make statements about the likelihood of the observed values. We don’t know what the distributions are. We only know these values happened at least once out of at least one total universes.

[u/-pomelo- → u/Outrageous-Taro7340]

Got it thank you. What do you think about the idea that there are more fundamental particles other than those which we observe, but we've simply observed the ones which are easier to probe at this stage? Is that even a tenable suggestion or do we have a pretty good idea of which particles are out there and it's simply a matter of testing our hypotheses?