What Does It Mean For A Proton To Contain "Intrinsic Charm"?

[ScienceNoob]

I've read this several times and I still don't understand how it makes sense. How can a proton contain a particle that's heavier than it is?

https://physicsworld.com/a/protons-contain-intrinsic-charm-quarks-machine-learning-analysis-suggests/

[Peter Pedant]

um see wiki - charm quark
my eyes glazed over

[jim360]

I'm not sure, is the honest answer, TTT -- I'd certainly want to stray away from talking about the "actual" mass in your analogy. But I'm worried that anything I say beyond that would end up being wrong or misleading.

[ToraToraTora]

Thanks, I'm just grateful that you didn't poo poo it out of hand!

[Peter Pedant]

I can understand JIm's two points ( axioms)
1) it is complex ( and keeps physicists alive)
2) mass isnt additive for subatomic particles - yup I can live with that

and the rest is social work ( Heisenberg actually)

[jim360]

Hi, gness, by the way :)

As to the original question, I glanced at one of the earlier papers on intrinsic charm ( https://sci-hub.se/10.1016/0370-2693(80)90364-0 , in case anyone is interested), and I think on reflection it even intersects with work I've done in the past, so I might be able to put together a reasonable explanation after all. More thinking needed, though.

* * *
For TTT: in any analogy that works, there has to be some measurable binding energy that affects the response to an external force. Equivalently, you either had to do work to bring the individual particles together, or you have to do work to take them apart. So in that sense I think two magnets would have a different effective mass from the sum of two individual magnets' masses. But the difference would be small and I'm still nervous that I've got this wrong.

[ToraToraTora]

Jim, yes I was using your statement:"Firstly, I think it's helpful to emphasise that mass is a measure of how reluctant something is to move" as a basis for the magnet hypothesis.

[Peter Pedant]

sci-hub.se - too slow to respond
just in case someone wondered if a punter had tried

[jim360]

sci-hub.se links should be ok -- if they're too slow it's possible that for whatever reason your ISP, or whatever, is blocking it, since technically it's not above-board. Although in my experience no scientists, least of all the authors, actually care if people use that to get around journal paywalls. Science should be free to access for all.

[beso]

The mass embodied in the binding energy is just another manifestation of m = E/c^2, Einstein's original rendition of the well known E= mc^2.

This formula applies at every level. It applies to chemical reactions but the difference in mass due to the binding energy of the electromagnetic forces involved in molecules is tiny compared to the mass of the atoms.

It is much larger when considering the forces that bind protons and neutrons in a nucleus but the comparative energy involved relative to the masses of the components inside a hadron such as a proton or neutron is enormous.

There is so much energy in there that it is the main contributor to the mass of the proton. All that energy floating around is capable of manifesting temporary extra particles under some circumstances, just as the vacuum itself is capable of doing with almost no energy.

However I'm still struggling to grasp that there can be a negative energy that would make a hadron weigh less than its components.

[Canary42]

Shouldn't this be in the Brain Frying thread - it's certainly frying mine.

:-D :-D :-D

[jim360]

// However I'm still struggling to grasp that there can be a negative energy that would make a hadron weigh less than its components. //

I started with the example of a nucleus, where the binding energy means the nucleus weighs less than the sum of the individual nucleons. It's obviously trickier in the case when there's an individual component that seems to have greater mass than the thing it's in. I still need to think about how to address this aspect without melting my brain, let alone anybody else's, but...

The binding energy inside protons and neutrons is even more of a mess. One particular aspect that confuses me is that some, or perhaps even most, of it is thought to be due to the quarks inside the proton etc flying around at close to the speed of light, and yet barely going anywhere. If you wanted to think about it in terms of something easier to picture, it's helpful to think I guess of gases, where the various gas molecules can be zipping around super-fast, but barely get anywhere before hitting something, so from a distance it looks like the air is still.

This *still* isn't addressing intrinsic charm, and I'm really sorry about that. But, yeah... particle physics is hard, and there's a lot to try and get your head round, and if y'all are patient I'll do my best to answer this and any other questions as best I can.

https://profmattstrassler.com/articles-and-posts/particle-physics-basics/the-structure-of-matter/protons-and-neutrons/