Standard model; why is it as it is? (Introduction)

by David Turell , Sunday, June 12, 2022, 01:13 (687 days ago) @ David Turell

We don't know:

https://bigthink.com/starts-with-a-bang/why-3-generations-particles/?utm_source=mailchi...

"Everything that exists in our Universe, as far as we understand it, is made up of particles and fields. At a fundamental level, you can break everything down until you reach the limit of divisibility; once things can be divided no further, we proclaim that we’ve landed upon an entity that’s truly fundamental. To the best of our current understanding, there are the known elementary particles — those represented by the Standard Model of elementary particle physics — and then there are the unknowns: things that must be out there beyond the confines of the Standard Model, but whose nature remains unknown to us.

"In the latter category are things like dark matter, dark energy, and the particle(s) responsible for creating the matter-antimatter asymmetry in our Universe, as well as any particles that would arise from a quantum theory of gravity. But even within the Standard Model, there are things for which we don’t quite have an adequate explanation. The Standard Model consists of two types of particles: (my bold)

"...the bosons, which mediate the various fundamental forces,
and the fermions, from which all the normal matter in the Universe is composed.
While there’s only one copy of each of the bosons, for some reason, there are three copies of each of the fermionic particles: they come in three generations. Although it’s long been accepted and robustly experimentally verified, the three-generational nature of the Standard Model is one of the great puzzles of nature. Here’s what we know so far. (my bold)

"Although the Standard Model possesses an incredibly powerful framework — leading to, by many measures, our most successful physical theory of all-time — it also has limitations. It makes a series of predictions that are very robust, but then has a large number of properties that we have no way of predicting: we simply have to go out and measure them to determine just how nature behaves.

***

"But what the Standard Model doesn’t tell us is also profound.

"1)It doesn’t tell us what the masses of any of the fundamental particles are; we have to go out and measure them.

"2)It doesn’t tell us whether the neutrinos are massive or massless; we had to measure their properties to determine that they are, in fact, massive, but with tiny masses compared to the rest of the Standard Model’s massive particles.

"3)It doesn’t tell us whether there will be multiple copies of the fermions in the Standard Model, how many of those copies there will be, or how the quarks and leptons from different generations will “mix” together.

"All of these things can only, at least as we currently understand it, be measured experimentally, and it’s from those experimental results that we can determine the answers.

***

"If you apply the Koide formula to the up, down, and strange quarks, you get a fraction that’s consistent, within the measurement errors, of 5/9.

"If you apply it to the charm, bottom, and top quarks, you get a fraction consistent with 2/3.

"And if you apply it to the W, Z, and Higgs bosons, you get a fraction consistent with 1/3.

"But even with all that said, there’s no underlying reason for any of this; it’s just a suggestive correlation. There may be a deep reason as to why there are three generations — no more, no less — of fermionic particles in the Standard Model, but as far as what that reason might be, we have no indicators or evidence that are any better than these tenuous connections.

"The experimental data and the theoretical structure of the Standard Model, combined, allow us to conclude with confidence that the Standard Model, as we presently construct it, is now complete. There are no more Standard Model particles out there, not in additional generations nor in any other yet-undiscovered place. But there are, at the same time, certainly puzzles about the nature of the Universe that require us to go beyond the Standard Model, or we’ll never understand dark matter, dark energy, the origin of the matter-antimatter asymmetry, and many other properties that the Universe certainly possesses. Perhaps, as we take steps towards solving those mysteries, we’ll take another step closer to understanding why the Standard Model’s particle content is neither greater nor lesser than it is."

Comment: his point is important: we can measure and correlate, but have no idea why things are arranged as they are. The deesigner knows, but He doesn't explain it. Just as He does not explian why He conducted the evolution of humans the way that He did. All that hapens is dhw wants answers that do not exist for his own analysis that confuses him about why God did it the way He did it. The best way to think about it is early on there were bacteria at the start of life. There followed a whole continuous series of increasingly complex steps until humans arrived. That is what happened. We can analyze it for clues of purpose. But the method happened and cannot be questioned in and of itsslf since it represents pure historical fact.