Photon Question: Attraction and Repulsion

  • Context: Graduate 
  • Thread starter Thread starter misogynisticfeminist
  • Start date Start date
  • Tags Tags
    Photon
Click For Summary

Discussion Overview

The discussion revolves around the nature of photons in the context of electromagnetism, specifically questioning whether there are different types of photons corresponding to attractive and repulsive forces. Participants explore the implications of photon spin and the interactions between electrons and positrons versus electron-electron interactions.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants propose that since electromagnetism has both attractive and repulsive effects, there should be two flavors of photons, one for each type of interaction.
  • One participant suggests that the spin of the photon could be related to the type of force (attraction or repulsion), raising questions about which spin corresponds to which force.
  • Another participant expresses uncertainty about whether spin alone can explain the differences in interactions, suggesting that properties of the wavefunction may be more relevant.
  • It is noted that two electrons do not interact in the same way as an electron and a positron, with references to tree diagrams illustrating these interactions.
  • One participant clarifies that the two spin states of electrons do not imply two different types of particles, emphasizing that electrons and positrons are distinct entities.
  • A request for sources or publications regarding the interaction diagrams is made, indicating a desire for further reading on the topic.
  • A reference to quantum field theory textbooks is provided as a resource for understanding the calculations involved in these interactions.

Areas of Agreement / Disagreement

Participants express differing views on the relationship between photon spin and the nature of electromagnetic interactions. There is no consensus on whether there are distinct types of photons or how spin relates to attraction and repulsion.

Contextual Notes

The discussion includes references to quantum field theory and tree diagrams, but the specific mathematical details and assumptions underlying these concepts remain unresolved.

misogynisticfeminist
Messages
370
Reaction score
0
Its a simple and elementary question, i think. Since electromagnetism has both attractive and repulsive effects and the photon is the quanta of this EM force, then shouldn't there be 2 flavours of photons?

Say, if and 2 electrons gets close each other, they exchange photons, which causes repulsion. But if an electron and positron get close, they too exchange the same photon but its attraction. Why?
 
Physics news on Phys.org
misogynisticfeminist said:
Its a simple and elementary question, i think. Since electromagnetism has both attractive and repulsive effects and the photon is the quanta of this EM force, then shouldn't there be 2 flavours of photons?

Say, if and 2 electrons gets close each other, they exchange photons, which causes repulsion. But if an electron and positron get close, they too exchange the same photon but its attraction. Why?

As a spin 1 particle (+ em wave transverse condition), you have 2 types of photons: the spin + and spin -.

Bravo!

Seratend.
 
whoa, haven't thought of spin, but which spin is associated with which force (i mean attraction or repulsion)?
 
I am not confident that spin fixes the problem because spin can be either way. Better see if there is some property of the wavefunction of the electrons/positrons/protons that accounts for it.
 
2 electrons don't interact in the same way as an electron interacting with a positron. You can see this by looking at the tree diagrams for these interactions.
 
seratend said:
As a spin 1 particle (+ em wave transverse condition), you have 2 types of photons: the spin + and spin -.

Bravo!

Seratend.
That isn't quite the same thing. Those aren't two particles. They are the exact same particles, they are just in different states. Electrons can be in either of two spin states +1/2 and -1/2. But there are electrons and positrons (anti-electrons)

Pete
 
jujio77 said:
2 electrons don't interact in the same way as an electron interacting with a positron. You can see this by looking at the tree diagrams for these interactions.

Where is that published? I want a copy.
 
Check any book on quantum field theory. When you calculate the amplitude for each process, whether it be electron electron, or electron positron interaction, you will see which diagrams contribute for each process.

Peskin is the common textbook for QFT, so if it isn't an example, it is probably a problem.
 

Similar threads

Replies
7
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 29 ·
Replies
29
Views
4K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 38 ·
2
Replies
38
Views
8K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 0 ·
Replies
0
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K