Question

does anyone know why atmospheric neutrinos are detected more frequently horizontally for high energies????
any help would be appreciated, thanks!

Answer 1

What's an atmospheric neutrino? And what does it mean to detect one horizontally? These may have obvious meanings in a specialized field, but they don't make sense to me a priori.

Answer 2

I know what a neutrino is, by the way, and where they come from and how they're detected. It's the adjectives "atmospheric" and "horizontal" that aren't makign sense to me here.

Answer 3

atmospheric neutrinos are produced in the atmosphere by pion decays (I think) and im doing a project using data from a detector in japan, Super kamiokande.

I've got to try and explain why theres a higher neutrino flux when cos theta=0, as opposed to any other angle i.e when theta =Pi/4
And i havent got a clue =s

Answer 4

Hmm, ok. So you're not looking at solar neutrinos? Because those would come preferentially from the direction of the Sun, of course. If you're looking at neutrinos from pion decay, then I would say they are most likely the debris from a cosmic ray air shower:

http://en.wikipedia.org/wiki/Air_shower_%28physics%29

Now I don't know much about air showers, but I would guess if you look in a direction in which you look through a thicker slice of the Earth's atmosphere, you will observe more debris, just because the original cosmic ray has a better chance of hitting something, and the debris particles have a better chance of hitting something else. That is, if you look parallel to the surface of the Earth, out towards space, you are looking through a thicker slice of atmosphere:

Maybe that helps? Anyway, if your source if air showers, maybe look up some of their characteristics. If your source is lower-energy charged particles (which doesn't seem super likely, as they aren't likely to be able to do nuclear reactions) then the Earth's magnetic field may make a difference. For air showers I think the particles are too energetic to notice the Earth's field, but I'm not sure.