U(1)B-L: Neutrino Physics and Inflation
Abstract
A gauged U(1)B-L symmetry predicts three right handed handed neutrinos and its spontaneous breaking automatically yields the seesaw mechanism. In a supersymmetric setting this breaking can be nicely linked with inflation to yield deltaT/ T proportional to (MB-L / MP)2, where MB-L (MP) denote the B-L breaking (Planck) scale. Thus MB-L is estimated to be of order 1016 GeV, and the heaviest right handed neutrino mass is less than or of order 1014 GeV. A second right handed neutrino turns out to have a mass of order 10-102 Tr, where Tr (<~109 GeV) denotes the reheat temperature. A U(1) R symmetry plays an essential role in implementing inflation and leptogenesis, resolving the MSSM mu problem and eliminating dimension five nucleon decay. An unbroken Z2 subgroup plays the role of matter parity. The scalar spectral index ns=0.99+-0.01 for the simplest models, while in smooth hybrid inflation ns>=0.97. The tensor to scalar ratio r is negligible, and dns/dlnk<~10-3.
Turn this paper into a full lesson
ArcXiv compiles a staged curriculum from this paper: 8-12 lessons across beginner → advanced, synthesised section guides, visuals, flashcards, a quiz, exercises, and on-demand deep dives per section. Grounded in the abstract, never invented.