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Comment by andrewflnr | Hacker News Reader

So... would this mean neutrinos are for sure not Majorana fermions? Because you'd think that a particle couldn't be its own anti-particle if it's anti-particle has different properties, but quantum mechanics has surprised me before.

https://en.wikipedia.org/wiki/Majorana_fermion

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It's a bit of a subtle point but Majorana anti-neutrinos are still right handed chiral particle and a Majorana neutrino is still a left handed particle. So any particle-antiparticle effects from Delta-CP (or anything else) just becomes a left-right chirality effect. That behavior is built right into the term "Delta-CP", CP stands for charge-parity, meaning it's related to both a charge flip (particle to anti-particle) or a parity flip (left to right).

This isn't a full explanation but I'd have to go find some old text-books in order to provide a better one. Here's also a blog post that kinda sorta addresses the same point https://www.quantumdiaries.org/2011/06/19/helicity-chirality...

The known, light neutrinos would be Dirac, their massive counterparts Majorana:

https://en.wikipedia.org/wiki/Seesaw_mechanism

Well it’s tricky, see. Normal science might try to solve a paradox logically, but maybe this is the universe solving a paradox by multiplying both sides of the equation by a reciprocal paradox? The different properties of the anti-particle result in a remainder which is where all of the something rather than nothing comes from.

I guess my metaphor was a little too fast and loose and lost some key detail. I don’t want to misrepresent the science so here’s a link that explains the math better than I can.

https://en.wikipedia.org/wiki/Spinor

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