I was involved in this analysis if anybody has questions (though the student and postdoc did most of the real work)
original article: https://arxiv.org/abs/2510.21104 or https://journals.aps.org/prl/abstract/10.1103/xwqy-yzrk
original article: https://arxiv.org/abs/2510.21104 or https://journals.aps.org/prl/abstract/10.1103/xwqy-yzrk
Is there any hope to have know more about them? To point at some and say "they are neutrinos" is a big promising step, but what about others? Was it a proton, or neutron, or electron or what? Where did this particle come from, and who was so pissed off to kick it that hard. I mean, I read wikipedia a lot, I have an idea what kind of processes can create these particles, but if we could find an extremely red shifted galaxy on a photo from James Webb and say that THAT proton came from there, it would be very nice.
But yes, one of the main reasons we are looking for ultra-energetic neutrinos is to try to understand the sources of high energy particles in general, as the highest energy charged particles are harder to point due to bending in magnetic fields. Measuring UHE protons from high red shifts is not possible due to the GZK mechanism, but that same mechanism will produce neutrinos that we are hoping to detect!