Some Thoughts on the Conference
The XVI edition of Neutrino Telescopes is over and it is the time for some summing up – which I feel completely unsuited to do, as I was just an observer. My field is high-energy collider physics, and neutrino physics has become a very different thing since the discovery of neutral currents 42 years ago. Anyway, here are a few random thoughts.
First of all, I am really envious of the degree of activity, the large number of interesting experiments, the many complementary sides that can be taken to attack the problem of understanding the riddles posed by the physics of neutrinos. Collider physics pales in comparison, with only few experiments really capable of producing breakthroughs. The reason of this difference is that in trying to break the Standard Model and finding new physics beyond it, collider physicists are condemned to look only in one direction, that of the smallest distance scales and highest collision energies. In contrast, the field of neutrino physics is still in its infancy: after the discovery of neutrino oscillations in 1998 there is still a lot to learn, and many parameters to measure. Those parameters are tightly interconnected by the theory, but surprisingly decoupled in the experimentally accessible ways to determine them.
Experimental techniques are also quite varied as the source of neutrinos is not one and the same: we can study reactor (anti)neutrinos, solar neutrinos, cosmic-ray-originated atmospheric neutrinos; or we can produce them with accelerators, and there too, one may distinguish short and long-baseline setups, which are sensitive to different propagation properties of the neutrino beams; and there one can study appearance or disappearance of neutrino flavors. But one can also study geo-neutrinos, learning about the core of our planet; or astrophysical sources of neutrinos, cosmogenic neutrinos. And one can detect supernova explosions with the neutrino fluxes. It is astounding how rich is the physics program and how varied the implications of measurements of the properties of just one particle -well, one kind of particle, but actually three, or more of them.
Another reason to be enthusiastic is the incredibly large scale of some of the experiments – IceCube, Pingu, Km3Net, and Juno are some notable examples. These are real telescopes looking at the cosmos, the sun, and our planet as well. It is remarkable how we can exploit the ice of the south polar cap as a detector, or the water of the marine depths. Equally awesome is to know how detectors weighing just a few kilograms can compete in determining crucial properties of neutrinos: these are the solid-state experiments looking for neutrinoless double-beta decays. Of course, you do not need large dimensions when your process of interest is neutrinoless!
It is also quite interesting to remain in touch with the development of neutrino studies because of the tight interconnections with cosmology: dark matter searches use partly the same experimental techniques, and are now getting sensitive to the region where we should really start to detect a signal from weakly-interacting massive particles. If we see no signal in the next generation of searches, we may have to revise our general understanding of the universe, as the “cosmic miracle” of a weak neutral particle produced in the big bang with just the right abundance and mass to explain dark matter away, ending up in the exact mass region of the electroweak scale, will cease to provide a motivation for that explanation. And of course, cosmogenic neutrinos may provide further evidence of our model of the cosmos, or create new questions.
Overall, it was a lot of fun to listen to the many talks – all of very high quality, thanks to the careful job of the organizing committee. The latter must also be acknowledged for flawlessly organizing a very pleasant week, with a splendid venue and excellent food, and with a successful poster session. I am sorry to say that my only contribution to the conference, this blog, did not shine as much, despite my efforts. The problem, as I see it, is that the blog was not kept in high regard by the local organizers, so it remained “on the side”. I believe a conference blog requires more effort from more parties, more commitment and advertisement, if it is to become a very useful addition to an already well-oiled and working conference. Do not get me wrong: I am overall satisfied by the number of visitors we had last week (over 500 per day) – by themselves, the numbers justify the effort; the conference proceedings will never get as many readers. However, there was no real effort of making the online discussions a virtual place where to keep in touch with the external world. This is probably due to the fact that online communication is still not kept in high regard by our community. This has to change, I think, or the gap between hard science and the rest of the world will grow bigger and basic research will stop looking like a good idea. I hope I’m wrong…