Dirac Neutrino Masses from Generalized Supersymmetry Breaking

Understand

We demonstrate that Dirac neutrino masses in the experimentally preferred range are generated within supersymmetric gauge extensions of the Standard Model with a generalized supersymmetry breaking sector.

• If the usual superpotential Yukawa couplings are forbidden by the additional gauge symmetry (such as a U(1)'), effective Dirac mass terms involving the "wrong Higgs" field can arise either at tree level due to hard supersymmetry breaking fermion Yukawa couplings, or at one-loop due to nonanalytic or "nonholomorphic" soft supersymmetry breaking trilinear scalar couplings.
• As both of these operators are naturally suppressed in generic models of supersymmetry breaking, the resulting neutrino masses are naturally in the sub-eV range.
• The neutrino magnetic and electric dipole moments resulting from the radiative mechanism also vanish at one-loop order.