Two electron relativistic corrections to PE

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Discussion Overview

The discussion revolves around the relativistic corrections to the Coulomb law for electron-electron interactions, specifically focusing on second-order corrections without considering spin. Participants explore various aspects of these corrections, including their mathematical forms and potential experimental implications.

Discussion Character

  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant inquires about the relativistic correction to the Coulomb law for two electrons, specifically seeking the next most significant correction term.
  • Another participant points out that standard references mention corrections proportional to the fourth power of momentum, questioning the context of "second order."
  • Some participants express uncertainty about whether the functional form of the corrections would differ between electron-electron and electron-proton interactions, noting that the bound state of hydrogen complicates the situation.
  • A participant presents a proposed expression for the potential, including a delta function term, and discusses its implications in momentum space.
  • Another participant references an effective field theory approach, suggesting that corrections due to quantum gravity are out of experimental reach, while also mentioning the need for coherent explanations in modeling.
  • One participant cites a reference from Bjorken and Drell regarding vacuum polarization and its relation to the Lamb shift, indicating that the delta function term affects only S states.
  • There is mention of the need for further exploration of the relationship between bound and unbound states in the context of these corrections.

Areas of Agreement / Disagreement

Participants express differing views on the nature of the corrections and their applicability, with no consensus reached on the specific forms or implications of the relativistic corrections discussed.

Contextual Notes

Some participants note that the corrections discussed may be out of reach for experimental verification, and there are references to various theoretical frameworks that may not directly apply to the specific case of electron-electron interactions.

Who May Find This Useful

Readers interested in advanced topics in quantum mechanics, relativistic corrections in particle physics, and theoretical modeling of fundamental forces may find this discussion relevant.

qsa
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What is the relativitic correction to the e^2/r coulomb law without spin between two electrons.second order is enough.
 
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Second order in what ? Standard references mention a correction proportional to the 4th power of momentum, if the electron's and the proton's spin are neglected.
 
dextercioby said:
Second order in what ? Standard references mention a correction proportional to the 4th power of momentum, if the electron's and the proton's spin are neglected.

I guess I wanted the next most significant correction term, also I want electron-electron not electron-proton(which is usually given as hydrogen atom). Can you please post some links to the standerd references that you mentioned.
 
Why would electron-electron have a different functional form than electron-proton?
 
Vanadium 50 said:
Why would electron-electron have a different functional form than electron-proton?

of course they shouln't but in case of hydrogen the system is in a bound state, I am not interested at such complication(if any) at this time.
 
What is the relativistic correction to the e^2/r coulomb law?

To the next order, V(r) = -(Ze2/4π)1/r - (Ze4/60π2m2) δ(r)

I know the delta function looks weird, like it was something just stuck in by hand. But that's really the result. It looks more sensible in momentum space, where

V(k) ~ k-2 (1 - (e2/60π2m2) k2 + ...)

and the Fourier transform of the second term is the Fourier transform of 1, which is a delta function.
 
I think you're looking for something like this qsa

Effective Field Theory of Gravity: Leading Quantum Gravitational Corrections to Newtons and Coulombs Law

where the first order correction is shown to be an additional

3G(m1+m2)/(r*c^2)

(multiplied by the classical coloumb term)

(obviously m1=m2 for the electron, and r is the separation)

But, personally, I would give up running naive random models in the hope of getting physical laws, you'll go crazy. If your new model matches this formula it's still not a big deal, especially not if you don't explain how it's constrained in a coherent and simple manner.
 
Bill_K said:
To the next order, V(r) = -(Ze2/4π)1/r - (Ze4/60π2m2) δ(r)

I know the delta function looks weird, like it was something just stuck in by hand. But that's really the result. It looks more sensible in momentum space, where

V(k) ~ k-2 (1 - (e2/60π2m2) k2 + ...)

and the Fourier transform of the second term is the Fourier transform of 1, which is a delta function.

Thank you. what is the order of magnitude of the extra term (lets say for Z=1)

(Ze4/60π2m2) δ(r)

is there any experimental confirmation. Do you have any links.
 
unusualname said:
I think you're looking for something like this qsa

Effective Field Theory of Gravity: Leading Quantum Gravitational Corrections to Newtons and Coulombs Law

where the first order correction is shown to be an additional

3G(m1+m2)/(r*c^2)

(multiplied by the classical coloumb term)

(obviously m1=m2 for the electron, and r is the separation)

But, personally, I would give up running naive random models in the hope of getting physical laws, you'll go crazy. If your new model matches this formula it's still not a big deal, especially not if you don't explain how it's constrained in a coherent and simple manner.

This is another story for another time since these corrections are out of reach of experiment. Bill_K gave the correct answer. As for my model ,you know I cannot talk about it here, I will send you an email soon with the latest results(maybe alpha up to eight digits).
 
  • #10
The reference for the expression I quoted is Bjorken and Drell, Vol I, Sect 8.2 on Vacuum Polarization, especially Eq 8.27. The delta function in the second term limits its effect to S states, since they are the only ones whose wavefunction does not vanish at the origin. This term is partially responsible for the Lamb shift, however the contribution to the Lamb shift from other effects is larger.
 
  • #11
qsa said:
This is another story for another time since these corrections are out of reach of experiment. Bill_K gave the correct answer. As for my model ,you know I cannot talk about it here, I will send you an email soon with the latest results(maybe alpha up to eight digits).


The paper says the corrections due to quantum gravity ( ~ Gh/(r^2c^3) ) are out of experimental reach, the relativistic correction is ~ Gm/(rc^2) (it summarises this in the summary).

But the paper talks about scalar (spin 0) particles (which is what you asked for) so wouldn't directly apply to a realistic situation (it mentions that there is an extension to spin 1/2 fermions)

I guess you just wanted radiative correction from qed (eg Landau & Lifgarbagez, Vol 4 QED 2nd Ed p 504).

Maybe if you get more decimal places you can try to match it with something more state of the art, good luck!
 
  • #12
Thanks to both of you. I wonder if this is from Breit or just Dirac. can anybody else help, I appreciate it? Is there a relation between bound and not bound states?
 

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