CERN questions - Neutrino Annihilations

​I've gotten some great questions already. A few I think I can address before I am on location. I'll tackle each in a separate post, as they require somewhat long answers.

"Mom" (my mom) asked something complicated, so I am going to refer you to a refresher video about sub-atomic particles. ​

What is a neutrino?

"Has anyone yet suspected they had detected neutrino-antineutrino interactions?" - Mom 

I think this is in reference to the Stanford (etc.) Enriched Xenon Observatory that looks for neutrino-less double beta decay, as she included the link.

The quick answer is,"not really, but..."

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​...but what?

​Particle/Anti-particle collisions are called annihilations. In the case of a neutrino-anti-neutrino annihilation, a Z boson is created. Z bosons are "in charge" (ahahahaha) of the Weak Nuclear NUKE-LEE-ER Force (like electricity, gravity, etc, but REALLY WEAK). W bosons are also in charge, and they are positive or negative. The Z boson has zero electric charge...so it's the Z boson.

​I spent all this time telling you about the Z boson, and now it's gone. We don't care about it anymore, we just care about the mess it left, which can be

1) another particle/anti-particle pair
2) two new neutrinos
3) two charged leptons
OR
4) a quark/anti-quark pair.

All that work I did explaining the Z boson was a bit misleading, as I am not going to describe any of the new "things" it pooped out. in this post. Maybe later.

​Anyway, the energy of neutrino/anti-neutrino that collided determines what the Z-boson leaves in the baby basket at the fire station.

The neutrino detector at the T2K Experiment in Japan. Pretty sweet, no?

Detecting neutrinos is a pain in the ass. I think there are only 12 detectors that were built/are being built, with, again, I think, only 8 in operation. Don't quote me on that.

Detecting the annihilations is even more of a pain in the ass. Think bee sting to bone marrow sample, on a much larger, cosmic scale.

Why?

The probability of a collision is extremely small. No, I don't know how small, but very, very, very small. Not "free ponies for all Americans" small, but small.

What is a supernova?

The best place to look for these collisions would be in a collapsing supernova, something that we may experience here in the States on November 2. We don't have a telescope that can detect particle sized interactions from that distance.



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Theoretically (again, enough with the Heisenberg), we could detect them on Earth. Supernova collapses do boost the flux of neutrinos, but happen unbearably fast, and not frequently. The last one was in 1987, and the existing neutrino observatories detected just 24 neutrinos in about 13 seconds. Then it was over. The only supernova recorded before that was in 1604, though it is possible there were a few more and we just didn't have good enough scopes yet.

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But can't we just ram a neutrino beam and an anti-neutrino beam together? Uh, kinda, but....

The beams would have to be super intense, and the particles very high energy. What's that, we can only see some neutrinos? Unfortunately, yes, and this is why we need more experimental physicists. The collisions must be high enough energy to produce electrons (aka beta particles); otherwise, they'll just produce more neutrinos, and neutrinos are hard enough to see in the first place.

Neutrinos are also a lot like my brain when I'm excited: no focus. These 'beams' wouldn't operate like nice little focused lasers that burn holes in things. Think of it as the difference between a dirty bomb and an actual hydrogen bomb. One goes poof and scatters, the other one melts everything in its path for kilometers.

I am quite positive this produced more questions than answers, but, I tried. Also, no guarantees on the absolute accuracy of anything I told you: I do not have a PhD in particle physics. It is very interesting, though!