The discussion centers on the decay processes of the neutral Σ particle, specifically why it predominantly decays into one or two photons and a neutral Λ particle, and the implications of weak interactions on potential alternative decay modes. The scope includes theoretical considerations and experimental observations in particle physics.
Participants express differing views on the decay processes of the neutral Σ particle, with no consensus reached regarding the viability of alternative decay modes or the implications of weak interactions. The discussion remains unresolved on several points, particularly regarding experimental verification of proposed decay channels.
Limitations include the lack of experimental data on certain decay modes and the dependence on theoretical models regarding decay processes. The discussion also highlights the complexity of interactions in particle physics, which may not have direct analogs in nuclear physics.
It could.Joker93 said:Hello!
I wanted to ask why does the neutral Σ decay almost always to one γ(or two) and a neutral Λ.
Why can't it decay to anything else?
Thanks!
Not quite "will", "no alternative". Compare with internal transition of nuclear isomers. There are excited states of nuclei for which electromagnetic decay to a lower lying state is possible but difficult enough that decay via weak interaction (beta decay) is a relevant competing process, or the prevalent ones.mfb said:If a particle can decay via the strong or electromagnetic interaction, then these decays will dominate. The weak interaction is weak - these decays are not impossible, but they are only relevant if there is no alternative to it (and typically the particles are long-living in this case).
mfb said:I‘m not aware of measurements of the branching fraction
mfb said:I don’t know any case in particle physics where possible electromagnetic decays are suppressed sufficiently to make weak decays compete with them.