2009

The B-L/Electroweak Hierarchy in Heterotic String and M-Theory

Ambroso, Michael, Ovrut, Burt

Understand

E8 x E8 heterotic string and M-theory, when compactified on a Calabi-Yau threefold admitting an SU(4) vector bundle with Wilson lines, can give rise to the exact MSSM spectrum with three right-handed neutrino chiral superields, one per family.

  • Rank preserving Wilson lines require that the standard model group be augmented by a gauged U(1)_B-L.
  • Since there are no fields in this theory for which 3(B-L) is an even, non-zero integer, the gauged B-L symmetry must be spontaneously broken at a low scale, not too far above the electroweak scale.
  • It is shown that in these heterotic standard models, the B-L symmetry can be broken, with a phenomenologically viable B-L/electroweak hierarchy, by at least one right-handed sneutrino acquiring a vacuum expectation value.

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