I don’t think that we will, but people are still looking for it, albeit indirectly, and focusing on special relativity. Stuff like “are the photons still obeying Lorenz symmetry here? What about there? And there?”. (Note: Lorenz symmetry violations would imply CPT violations.)
Thank you for the thoughtful response, as I was genuinely interested to know what axion was.
As a side note, I remember reading about CP violations a while back (scientists love to use the metaphor of “how to distinguish left from right” to explaining those) and they were saying that Time (T) was inviolable, but they did also thought the same about Charge © and Parity (P) before. Do you think we will ever see a CPT violation?
I don’t think that we will, but people are still looking for it, albeit indirectly, and focusing on special relativity. Stuff like “are the photons still obeying Lorenz symmetry here? What about there? And there?”. (Note: Lorenz symmetry violations would imply CPT violations.)