Talk:Naturalness (physics)

Expert needed

I find everything related to the gauge hierarchy problem and supersymmetry of much too high level for wikipedia. It completely misses links to other pages (there isn't even one to the susy or standard model pages). It uses a lot of jargon that would be introduced in an advanced particle-physics lecture. I think it should be shortened by an expert. Pkoppenb (talk) 15:15, 16 November 2017 (UTC)

I have a master in theoretical physics, but am unable to understand the introduction of this article. 2A02:A44E:8E97:1:4480:B9D3:DB57:2963 (talk) 16:14, 26 May 2021 (UTC)

Suggestion to add a section connecting naturalness to the renormalization group

I must admit that I never understood what naturalness is in high-energy physics until I read Polchinksi's explanation here https://arxiv.org/abs/hep-th/9210046 which connects naturalness to the renormalization group.

Let me try to paraphrase his line of thought: He connects the naturalness problem to superrenormalizable (aka relevant) couplings in the Lagrangian. If we have a physical theory defined by a Lagrangian at some high-energy cutoff $\Lambda$, we can obtain an effective theory for some low-energy cutoff $\lambda$ by following the renormalization group flow which gives us the values of the couplings at the low-energy cut-off. But if some term in the Lagrangian is super-renormalizable (i.e., relevant), this means that the term will grow as we move to lower and lower energies. If we follow the renormalization group flow from the high-energy cut-off $\Lambda$ to $\lambda \ll \Lambda$, the coefficient in the Lagrangian will grow by some power of $\Lambda /\lambda$. This means that the super-renormalizable coupling will dominate all other terms that are present in the high-energy Lagrangian. Consequently, the low-energy physics will be very different from the high-energy physics unless we fine-tune the coupling in the high-energy theory to give us a sufficiently small effective coupling at low energies.

I am aware that the above description is still far too technical for Wikipedia, but it would at least allow us to make a connection with the renormalization group article. My suggestion would be to add a section "Connection to the renormalization group" with content along the lines outlined above, potentially simplified. However, my background is in condensed matter physics and not in high-energy physics, so I am not sure whether this misses a relevant aspect of naturalness. Could someone with an appropriate background in high-energy physics comment? If you have other thoughts on this suggestion, I would be happy to hear them as well. Jascha Tempeler (talk) 14:34, 10 September 2021 (UTC)