Witten of the arguments about B-L symmetry

[arivero]

I have found this small review by Witten of the arguments about B-L symmetry and its role in neutrino masses. http://arxiv.org/abs/hep-ph/0006332

I have been always amazed about the mismatch between the role of this symmetry in any attempt to unify interactions, including Weinberg-Salam, and the role it has in standard graduate lectures, where it is barely mentioned.

On a speculative mood, I wonder how B-L should appear in Kaluza Klein theory. Should a "ungauged" symmetry amount to an infinitesimal extra dimension? It is interesting to remark that Bailin and Love needed to add one dimension to sugra in order to get the right quark and lepton charges. And that SU(5), Pati-Salam (because of B-L), and SO(10) seem to live beyond 11 dimensions; this is obvious for SO(10) -symmetries of the 9dim sphere- and less obvious for SU(5) (with a subgroup H=SU(4)xU(1), it can live in dimension 24-15-1=8).

 

[Almsco]

Thanks for sharing this article! I'm also interested to know more about the role of B-L symmetry and its implications for neutrino masses. It's really interesting that the B-L symmetry is mentioned in attempts to unify interactions, but not so much in graduate lectures. Kaluza Klein theory does sound fascinating, especially since it seems to involve extra dimensions. It's quite intriguing to think about the fact that SU(5), Pati-Salam, and SO(10) appear to live beyond 11 dimensions.