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zahlman

The implication of this framing is that neutrons are considerably simpler.

I find that rather surprising.

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Neutrons are just as complex, they’re much harder to study though.

If it was possible to build a direct neutron accelerator/collider, I suspect we'd get some new physics pretty quickly.

Analysing hand-me-down neutron events from indirect collisions isn't quite as useful.

Neutrons are not that different from protons. The decay from neutrons to protons is pretty well understood, and there’s no reason to think that the nature of quark/gluon interactions in a neutron are significantly different from those in a proton. What kind of new physics are you imagining we’d get?

Of course more experimental data is a good thing, but in this case it doesn’t seem obvious that it would lead to anything really new.

Why do you say they're "pretty well understood" when there's been a long-standing unresolved discrepancy between lifetime measurement techniques?

I think they mean that what happens when a neutron decays is well understood. One of the neutron's down quarks change to an up quark, facilitated by a virtual W boson with negative charge. The W boson is very unstable and immediately decays into an electron and an electron anti-neutrino, both of which are ejected leaving behind the former neutrino which is now a proton because of that quark change.

When that happens is less understood, hence the discrepancies you mentioned.

The same QCD theory that's used to model the proton models the neutron. Theoretically, our understanding of both is on the same footing.

The comment I replied to talked about "new physics". That's a term that's used in physics to describe physics beyond the Standard Model. Better experimental data about neutron internals could certainly help constrain the neutron lifetime, but that would be likely to be experimental constraints on existing physics, not new physics in the sense that the term is normally used.

There absolutely are direct neutron experiments, but they are much lower energy and have a different focus, partly because neutrons being neutral means they’re very hard to accelerate.

There’s an ultra cold neutron source at Paul Scherrer that is used to measure if the neutron has an electric dipole moment. This is complementary to high energy experiments.

At ISIS (Oxford neutron source)…

Spallation generation: High-energy protons (~800 MeV) hit a heavy target, releasing a wide spectrum of fast neutrons up to hundreds of MeV. These are then moderated down to useful energies for experiments.

It’s not the LHC, sure. But I don’t see any reason (apart from “why bother”) why they can’t do spallation in Geneva. OK maybe there’s a cooling problem…

Spallation is the easy part

But neutrons can't go around a tube being guided by magnetic fields

Well my point is that the energy of the spallation neutrons is monotonically related to the energy of the protons hitting the Tungsten target ... although somewhat lower. I would consider these 100s MeV partiles to be (quite) high energy in contrast to the thermal neutrons alluded to elsewhere. Sure the spallation is lossy, but the result is still pretty high. And the physics is somewhat different with neutron experiments vs. protons... iiuc

If i remember correctly Feynman said in one of his lectures that we know the mass of the electron with much greater precision than the proton, which may mean that it electrons are easier to study. I don't know if this is still true though.

And neutrons are neither.

Oh yes and so much so! Electrons are point-like (not composite like a proton) and interact only electroweakly (not strongly).

> point-like

Oh, your going to love this theory.

https://fondationlouisdebroglie.org/AFLB-222/MARK.TEX2.pdf

In summary, There is a way to model electrons as a twisted self enclosed em field.

A decent digest summary of the paper is this video

https://www.youtube.com/watch?v=hYyrgDEJLOA (Huygens Optics: Are Electrons made of Light? )

Where are you getting that implication? I didn't see anything in the article suggesting that neutrons were simple and I would share your skepticism if someone claimed they were. The fact that neutrons can spontaneously decay into protons (plus other stuff) suggests otherwise.

The title implies it directly.

If you saw an article titled “My Nana is the nicest person you could possibly meet”, would you interpret that to be a statement that your own grandmother is considerably less nice?

That is what the author would be implying, yes. Though, you may quibble over "considerable".

Pedantry is rarely a good look. But intentionally misreading intent barely even qualifies as pedantry.

I like to imagine that people this ridiculous get into fist fights on the street constantly.

Normal person: “My wife is the absolute best.”

Pedant: “Don’t you dare insult my wife!” fists fly

Because the failure to write about neutrons is conspicuous considering that they're always together in nuclei, similarly composed of three quarks etc.

I don't expect that to be the case, it's likely that the article simply focuses on the proton.

Neutrons decay into protons, so no. They're less stable than protons. If we figure put the proton we can then use that to understand the neutron.

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