View Full Version : Leptogenesis, mu-tau symmetry

2004-Nov-27, 05:02 PM
Here's an interesting paper on Leptogenesis and its relation to mu-tau symmetry and the implications of this symmetry. How it may help science in the long run, I'm not sure, but its a fun read, has complex math with clear, simple walkthroughs, and here's (http://www.arxiv.org/PS_cache/hep-ph/pdf/0410/0410369.pdf) the link.

And, as I always do, the abstract:

If an exact $\mu\leftrightarrow \tau$ symmetry is the explanation of the maximal atmospheric neutrino mixing angle, it has interesting implications for origin of matter via leptogenesis in models where small neutrino masses arise via the seesaw mechanism. For seesaw models with two right handed neutrinos $(N_\mu, N_\tau)$, lepton asymmetry vanishes in the exact $\mu\leftrightarrow \tau$ symmetric limit, even though there are nonvanishing Majorana phases in the neutrino mixing matrix. On the other hand, for three right handed neutrino models, lepton asymmetry nonzero and is given directly by the solar mass difference square. We also find an upper bound on the lightest neutrino mass.

2004-Nov-27, 05:23 PM
gives an upper limit on the lightest neutrino mass of a milli-eV.

This is an interesting find. Thanks Starlab.

2004-Nov-27, 08:29 PM
Leptogenesis, mu-tau symmetry

Sounds like some oriental religion! :D

2004-Nov-27, 11:33 PM
That was a lot of fun. thanks. Contingent on his assumption set (not plausible, even to him) the conclusion of the mass of the electron-type neutrino being .001 eV was very comforting. One of the other ones, though was the mass of a pony. For the author. the entire paper was a what-if exercise. The linkage between leptogenesis and the origin of mass is very tricky. I haven't seen anyone do it convincingly. Lest you think that I was able to hang with him through all the math-- I couldn't, but my broad-but-shallow outlook gifts me with a pretty accurate bovine scatology detector. This is good stuff. Thanks, Starlab! Steve

2004-Dec-01, 10:07 PM
Ok, well all of this is jibberish to me. What classes must you have under your belt to get something from this stuff or are all you guys geniuses?