Discussion Overview
The discussion centers on the energy dependence of cross sections in particle collisions, specifically addressing the apparent contradiction between the expected behavior of hard cross-sections in inelastic scattering and the observed increase in cross-sections for proton-proton collisions as energy rises. Participants seek explanations and references for this phenomenon.
Discussion Character
- Debate/contested
- Technical explanation
Main Points Raised
- One participant notes that the hard cross-section for 2 to 2 inelastic scattering behaves as 1/E^2, while the cross-section in proton-proton collisions increases with energy.
- Another participant suggests a reference to a book by Forshaw and Ross and an arXiv paper for further reading on the topic.
- One participant proposes that the increase in cross-section with energy is due to the repulsive nature of protons, suggesting that higher energy allows protons to get closer together without being deflected as much.
- A later reply challenges the previous assumption, stating that the cross-section for proton-proton and proton-antiproton collisions is the same at high energies, indicating a flaw in the initial reasoning.
- This participant recalls that the increase in cross-section may relate to the "reggeization" of gluons exchanged during collisions, although they admit to not being able to fully reproduce the argument.
- Another participant expresses uncertainty about their initial guess regarding the repulsion of protons and acknowledges a lack of deep understanding of the topic.
Areas of Agreement / Disagreement
Participants do not reach a consensus on the explanation for the increase in cross-section with energy, with multiple competing views and uncertainties remaining in the discussion.
Contextual Notes
Some arguments rely on assumptions about the behavior of protons at different energy levels, and the discussion highlights the complexity of the interactions involved, including the role of gluons and the specifics of collision types.