Feynman Diagrams - A Level Physics

This video introduces and explains Feynman Diagrams for A Level Physics.

Feynman diagrams should be familiar to you as the Physics Online logo is one! Particle interactions are described by Feynman diagrams as they interact. Two particles, that interact via a force, exchange a force exchange particle called a boson which 'carries' the force.

An important interaction that we can display with a Feynman diagram is beta decay.

Thanks for watching,

Lewis

This video is recommended for anyone studying A Level Physics in the following exam boards:
AQA
CIE
Eduqas
WJEC

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[nathanchetram]

Excellent explanation, really love the demonstration with legos!

[SaraAhmed-iy]

you explained this way better than my third year uni physics professor

[PhilipTower]

Best channel for particle physics videos on the whole of YouTube! Do turn off autofocus on your camera though

[adriancoronel]

Muchas gracias por tu excelente explicacion, saludos cordiales desde México.

[joeallen]

Wish id have found this channel earlier than a couple of hours before my exam

[MarkTurnerChromium]

If the vertical axis is time, then how does the anti electron neutrino go back in time?

[MidnightStorm]

1:43 what we have now is your logo lol

[sawayachannel]

It was a good video, i just think it might help to add the type of exchange particle (e.g. w- or w+). Was a great vid even without them

[EpicHypercar]

These videos are really helping me. Thanks for posting these! :)

[abhinavmusic]

I have a question, which electron in this case would emit a photon? Also how would it effect the energy state of the electron that emits the photon?

[antoniomendoza]

Hello,

Good explanation... just wondering if the bosons are supposed to be represented as dashed lines. The squigly line is supposed to be a representation of photons right? Feel free to correct me... Thanks!

[rseyedoc]

The two electrons exchange a photon to "know" each other are there and repel, but don't they have to know each other are there first to in order to exchange the photon? Are the electrons constantly emitting photons and one randomly hits the other? Seems they would quickly run out photons that way. If they don't know each other are there, what triggers the photon exchange?

[jas]

Hello sir I have a couple of questions that are really bugging me :((
-How do protons turn into neutrons in positron emission when neutrons are heavier?
-In my textbook, it says that the 'proton is the only stable baryon', meaning that it doesnt decay, but, in positron emission, they turn into neutrons?!
-How do protons emit a W+ boson when the mass of a W+ boson is 80 times heavier than the mass of the proton itself?

Thanks so much

[pankajsrivastav]

Does this st.lines represent the trajectory of the particle??and if yes then we know that we can't know the trajectory of the particle and my 2 question is what will be the Feynman diagram to show attractive force between electron and proton

[HMPGENERAL]

Hi Sir, I remember there being a ~30 minute revision video of the entirety of the particle physics spec put together, similar to the A Level Waves one you made, has this been taken down? If not, where can I find access to it?

[adespade]

So does an electron on it's own, keep emitting photons, or only when a charged particle is near (how does it know)
so does the lone electron then keep losing energy ?

[Sam-uymv]

Why is it that the proton in on one side of the boson, yet the positron neutrino and the electron are on the other side??

[seef]

But how does it know to release a particle to let the other one know it’s there, or are they just releasing particles all the time?

[benjaminfranklin]

Pls, do the particles keep on releasing photons at any given time, or only when coming near a different particle

[marniesmith]

I don't think you're supposed to reverse the direction of the arrow for the antineutrino in the AQA spec