3 ms·

As is typical of LBL, they don’t also note the leading theories place majorana characteristics in a very small probability regime (particles are more and more d

As is typical of LBL, they don’t also note the leading theories place majorana characteristics in a very small probability regime (particles are more and more demonstrating Dirac characteristics). Demonstration of neutrino less double beta decay would prove majorana conjectures and point to fractures in the “standard model of physics” meaning new fundamental particles would be needed. In my opinion whoever measures the CvB (cosmic neutrino background) will be more compelling because it isn’t a nullification result, it’s a result that would tell us far more about the Big Bang than we know now. Neutrinos are hard to measure, have been the source of a lot of Nobel prizes! Disclaimer: I use to work at lbl

jessriedel 2y ago
The CvB is the holy grail. But it is an insanely challenging detection problem. I think the (multidecade?) PTOLEMY experiment is the only serious proposal, and particle physicists I knew were pretty skeptical it could actually pull it off for SM neutrinos. https://arxiv.org/abs/1902.05508 https://arxiv.org/abs/1902.05508
- initramfs 2y ago
  Interesting, I read about neutrinos a while back https://arxiv.org/pdf/2304.14995 https://arxiv.org/pdf/2304.14995 https://www.universetoday.com/13052/do-advanced-civilizations-communicate-with-neutrinos/ https://www.universetoday.com/13052/do-advanced-civilization... (I was reminded of this recently after watching the Three Body Problem - Tencent's version, interstellar quantum communication)
- SaberTail 2y ago
  I used to work in neutrino physics, and I will consider myself lucky if I see a detection of the cosmic neutrino background in my lifetime (roughly the next 50 years).
dphidt 2y ago
If there's a prior in the community, my impression (as a neutrino physicist) is that if anything it's more toward Majorana than not, in the absence of evidence either way. It is surely nicer from a theory perspective, with a (seesaw) mechanism to help explain the very light neutrino masses, and lepton number violation that helps in the case for leptogenesis as an explanation for the universe's matter-antimatter asymmetry, etc. One way I think about it is that it's pretty interesting either way: Majorana demands physics beyond the Standard Model, while Dirac would seem to suggest that lepton number is more than an accidental symmetry of the Standard Model, implying some unknown quantum number. Meanwhile, many experimental searches for neutrinoless double beta decay go on, with many new/clever ideas to carve through the quite large allowed parameter space.

jessriedel 2y ago

The CvB is the holy grail. But it is an insanely challenging detection problem. I think the (multidecade?) PTOLEMY experiment is the only serious proposal, and particle physicists I knew were pretty skeptical it could actually pull it off for SM neutrinos. https://arxiv.org/abs/1902.05508 https://arxiv.org/abs/1902.05508

initramfs 2y ago
Interesting, I read about neutrinos a while back https://arxiv.org/pdf/2304.14995 https://arxiv.org/pdf/2304.14995 https://www.universetoday.com/13052/do-advanced-civilizations-communicate-with-neutrinos/ https://www.universetoday.com/13052/do-advanced-civilization... (I was reminded of this recently after watching the Three Body Problem - Tencent's version, interstellar quantum communication)
SaberTail 2y ago
I used to work in neutrino physics, and I will consider myself lucky if I see a detection of the cosmic neutrino background in my lifetime (roughly the next 50 years).

dphidt 2y ago

If there's a prior in the community, my impression (as a neutrino physicist) is that if anything it's more toward Majorana than not, in the absence of evidence either way. It is surely nicer from a theory perspective, with a (seesaw) mechanism to help explain the very light neutrino masses, and lepton number violation that helps in the case for leptogenesis as an explanation for the universe's matter-antimatter asymmetry, etc. One way I think about it is that it's pretty interesting either way: Majorana demands physics beyond the Standard Model, while Dirac would seem to suggest that lepton number is more than an accidental symmetry of the Standard Model, implying some unknown quantum number. Meanwhile, many experimental searches for neutrinoless double beta decay go on, with many new/clever ideas to carve through the quite large allowed parameter space.