Why do photons behave differently than particles in scattering processes?

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Photons behave differently than particles in scattering processes due to their lack of mass and the nature of their interactions. While particles scatter directly in collisions, photons can scatter indirectly through the creation of virtual electron-positron pairs, although this occurs with a very low probability. The complexity of the Feynman diagrams involved in photon-photon interactions, which require multiple vertices, contributes to the reduced likelihood of scattering. The exchange of bosons or electrons in these processes is dictated by the underlying principles of quantum electrodynamics (QED). Understanding these interactions requires a deeper exploration of QED and related resources.
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Why do particles scatter in particle-particle collision while photons don't in photon-photon collisions, assuming that photons don't have enough energy to create particle anti-particle pairs?
 
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What force would do the scattering ?
 
ie.. they have no mass
 
CassiopeiaA said:
Why do particles scatter in particle-particle collision while photons don't in photon-photon collisions,

Photons can in fact scatter off each other "indirectly", via intermediate virtual electron-positron pairs. See e.g. page 4 (problem 3) of this document:

http://faculty.ucmerced.edu/dkiley/Physics161Fall2011HW2solns.pdf

The cross-section (i.e. the probability) is very small because the Feynman diagram has four vertices as opposed to only two in electron-electron scattering.
 
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I have very little knowledge of QED, but can you tell me what dictates exchange of bosons (particle-particle interaction) or electrons (in case of photon-photon interaction) in scattering processes? It will be helpful if you provide some links to further illustrate the point.
 
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