Discussion Overview
The discussion revolves around the status of massive gauge bosons, specifically W and Z bosons, in the context of quantum field theory (QFT) in/out states. Participants explore whether these particles can be considered as real states or if they are confined to being virtual particles within Feynman diagrams, given their finite lifetimes and resonance characteristics.
Discussion Character
- Debate/contested
- Technical explanation
- Conceptual clarification
Main Points Raised
- Some participants question whether massive gauge bosons, due to their finite half-lives, can be included in the asymptotic in/out states of QFT.
- Others argue that the detection of W and Z bosons in experiments, such as bubble or cloud chambers, suggests their "real" existence, although this is contested.
- Some participants assert that W and Z bosons are resonances and thus do not correspond to asymptotic free states, while others differentiate between resonances and virtual particles.
- A calculation presented indicates that the W boson’s short lifetime results in a track that is difficult to observe, raising questions about the practical implications of its detection.
- There is a discussion about the differences between resonances and virtual particles, with some participants suggesting that resonances correspond to states in the Hilbert space but do not survive to asymptotic infinity.
- Participants explore the implications of U238 atoms in relation to in/out states, with varying opinions on their status compared to W bosons.
- Some participants propose that while U238 may appear in an in/out state, the treatment of short-lived resonances like W and Z bosons requires careful consideration of the mathematical framework used in QFT.
Areas of Agreement / Disagreement
Participants do not reach a consensus on whether massive gauge bosons can be included in asymptotic in/out states. There are multiple competing views regarding the nature of resonances versus virtual particles, and the implications of these distinctions remain unresolved.
Contextual Notes
The discussion highlights limitations in the understanding of how resonances and virtual particles are treated in QFT, particularly regarding their mathematical representation and physical implications. The differences in lifetimes and decay characteristics of particles like W, Z, and U238 are also noted as significant factors in the discussion.