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I've seen charts with that info, but I don't know how... How can I calculate that ratio?

I've looked everywhere, and I can't find anything...

Thanks

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- Thread starter tzukishiro
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- #1

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I've seen charts with that info, but I don't know how... How can I calculate that ratio?

I've looked everywhere, and I can't find anything...

Thanks

- #2

ChrisVer

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http://hyperphysics.phy-astr.gsu.edu/hbase/forces/couple.html

So I wouldn't say it's e-07 times smaller than the EM force....

So I wouldn't say it's e-07 times smaller than the EM force....

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- #3

Vanadium 50

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I've seen charts with that info

Where?

- #4

nrqed

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He probably saw it in this poster: http://www.quick-facts.co.uk/images/medium_particle_chart.jpgWhere?

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- #5

nrqed

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But this table talks about the coupling constants, his question is about the force between two protons in a nucleushttp://hyperphysics.phy-astr.gsu.edu/hbase/forces/couple.html

So I wouldn't say it's e-07 times smaller than the EM force....

- #6

mfb

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- #7

phyzguy

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While you're at it, why is gravitation ~10^40 times weaker than electromagnetism? We don't know.

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Hmm, but then how did people come into the conclusion of my question? And yes, it's from that poster and a teacher also proposed the question in a class, I've been so confused and desperate looking into it hahah

- #9

nrqed

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Do you know a bit of particle physics? For the electromagnetic force, you may simply use Coulomb's law with a typical value for the size of a nucleus.Hmm, but then how did people come into the conclusion of my question? And yes, it's from that poster and a teacher also proposed the question in a class, I've been so confused and desperate looking into it hahah

For the weak interaction, you may use Fermi's four-fermion approximation where the coupling constant is basically Fermi's constant ##G_F/2## (at least I think there is a factor of 2 there) whose value you may look up. The units will not be the same and some work is required there. I would personally simply use ##\alpha_{em}/q^2 ## for the electromagnetic force, with ##q## the momentum corresponding to the size of a nucleus. And then the answer will basically be ##G_F## divided by ##\alpha_{em}/q^2 ##.

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Do you know a bit of particle physics? For the electromagnetic force, you may simply use Coulomb's law with a typical value for the size of a nucleus.

For the weak interaction, you may use Fermi's four-fermion approximation where the coupling constant is basically Fermi's constant ##G_F/2## (at least I think there is a factor of 2 there) whose value you may look up. The units will not be the same and some work is required there. I would personally simply use ##\alpha_{em}/q^2 ## for the electromagnetic force, with ##q## the momentum corresponding to the size of a nucleus. And then the answer will basically be ##G_F## divided by ##\alpha_{em}/q^2 ##.

In a very broad way, I'm not a physics student, but I took this course because we need to have a certain amount of courses outside our own field to graduate.

We don't really go into the math and hard deep physics of it, it's very superficial.

Gf divided by alpha/q^2 would give me said ratio? That kinda lost me, sorry

- #11

mfb

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The photon is massless, therefore the electrostatic force follows an inverse square law. The force between the protons is ##F=\frac{q^2}{4 \pi \epsilon_0} \frac{1}{r^2} = 920 N##.

The Z boson also leads to a force, but the Z has a nonzero mass. This leads to a Yukawa potential. The scaling constant k there can be taken as the ratio (speed of light)/(planck constant). Multiplying this with the Z mass and 0.5 femtometer gives -36, and ##e^{-36} \approx 2.3 \cdot 10^{-16}##. The prefactor we get from this page and messing around a bit, giving 1.1*10

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