The standard model: what's the evidence for the quark?

The evidence for the standard model comes from deep inelastic collisions studies at SLAC and at other particle accelerators and confirm the reality of the quark and boson that make up protons, neutrons and other hadrons.
This video reviews the initial problems with the standard model as devised by Murray Gell-Mann and the validation of the model through particle accelerator studies in the 70's and 80's.

Credit : CERN for animation

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[markhousman]

This helped me a lot. Most other standard model videos I have watch just present the theory as if Moses brought it down from the mountaintop. Thanks for taking the time to explain a bit about the experiments that back up the theory.

[ableone]

Excellent presentation. Thank you for your work. Very clear explanation of our current understanding.

[abdullahcelik]

Hi, can you share the papers of the graphs you used. Great video by the way.

[MrBendybruce]

What a great channel glad I stumbled upon it. I have a dumb question relating to the Higgs Boson. My understanding is it was discovered by high energy collisions which "created it". It then decayed almost immediately, and it was the particles that it decayed into which were actually detected, and thus its existence was inferred. My question is, if the Higgs is so unstable, and requires very high energy to create it, then how exactly can it "be everywhere" adding a small amount of mass to other particles? I've heard it described as the Higgs field, but I'm getting the feeling that this field is not the same thing as the particle itself. If so, then what is the Higgs field, and how does it actually relate to the Higgs Boson? Again, this is probably me just being stupid, I'm just a curious layperson, but I feel like I'm missing something.

[fahadapnsteiger]

Excellent video Sir!
A video about spin will be great

[andrewtiffany]

Great stuff - sharing with my IB students!

[kaushikkvasan]

How do we know that color charge really exists ?
How many point like structures did the proton have, in the experiments ?

[Balajiraja]

It is really an excellent video, what i understood from this is without boson nothing can withstand for attraction and no shape for atom and everything will fall without glueing b/w quarks. Pls correct me if wrong.

[fabienleguen]

Great content thanks ! That's a shame that this video has only 2092 views. Liked and subscribed.

[_nikeee]

Great Video!

I always thought that quarks are only observable when combining with other quarks to form neutral charge. How can the electron „feel“ 3 different quarks (which are non-neutral for themselves)?

[dugger]

This is a great video. Your view and sub count should be way higher.

[gadzirayi]

What software do you use for your presentation?

[enotdetcelfer]

This kind of stuff makes me feel so, so lucky to be alive right now

[LuisAldamiz]

That was a great explanation. I subscribed right away. TY.

A question that buzzes me is why is the neutron larger in size than the proton (as I've seen claimed somewhere) if they are affected by the same color forces with negligible differences?

[rikarch]

This is an excellent and clear explanation of the quark model and it's apparent experimental evidence. It does leave me a bit confused though (not the explanation, the actual accepted physics). When discussing the structure of a meson you put a green quark and an anti-green quark to together. Why do they not annihilate each other as matter and corresponding anti-matter normally do? The idea that you have to invent a new quantum property (color charge) to satisfy the Fermi exclusion principle is reminiscent of the creation of epicycles to explain planetary orbits prior to the understanding of Newton's gravity. Why do we not see this property in other particles? If it is the strong nuclear force that holds quarks together and prevents the independent detection of them, why is it this doesn't apply to the strong nuclear force between protons and neutrons? Is it possible to interpret the SLAC data differently? Did the SLAC experiment create neutrons? How did they account for energy loss due to neutrino creation? With all that activity going on inside a proton why is it so much more stable than a neutron? I am very much looking forward to your video on the Standard Model.

[gregmonks]

This strikes me as being similar to Linear Arithmetic Multi-Timbral Sound Technology which divides sound into something like 137 partials, each sound consisting of 3 partials. Each partial on its own is virtual- it takes three to make an actual sound.

[jasonwiley]

Thwre is another property -color. How does it fit into the standard model.

[PaulMarostica]

The evidence for quarks included protons having inside them pointlike objects all having spin 1/2 and fractional charges. Were the fractions +2/3 and -1/3 as assumed in the quark model of the proton?

[paulwalsh]

This did help, no doubt about that. But I'm still confused. I know the answer to my question "What is the evidence for quarks and quantum electrodynamics and quantum chromodynamics ?" is "Particle accelerators"; but how was things like spin, fractional charge and masses of particles discerned ?
And even though the animation of the rays from particle accelerators was fantastic, I still don't know if those rays are trajectories of quarks or streams of quark/anti-quark pairs produces in the collisions. That seemed still unclear.
Still this video was far and away more illuminating than other videos or texts that I have read.
EDIT: I watched a video referred to in an answer to another comment below explaining spin, which was excellent again, thank you. But still how were these properties DISCOVERED ? I would really like to understand and share my understanding with others, but I really prefer the history and methods of obtaining the evidence for the fullest picture. Again, your videos really help and hopefully as I delve further into your archive the answers will be revealed !

[DrDeuteron]

now the elastic scattering curve at 13:00 isn't a "what if", it is measured data.