John March-Russell

Abstract:

We analyze a class of supersymmetric models first introduced by Arkani-Hamed et al and Borzumati et al in which the light neutrino masses result from higher-dimensional supersymmetry-breaking terms in the MSSM super- and Kahler-potentials. The mechanism is closely related to the Giudice-Masiero mechanism for the MSSM $\mu$ parameter, and leads to TeV-scale right-handed neutrino and sneutrino states, that are in principle accessible to direct experimental study. The dominant contribution to the light neutrino (Majorana) mass matrix is a one-loop term induced by a lepton-number violating $B$-term for the sneutrino states that is naturally present. We focus upon the simplification and analysis of the flavour structure of this general class of models, finding that simple and novel origins for the light neutrino mass matrix are possible. We find that a subdominant tree-level `see-saw' contribution may lead to interesting perturbations of the leading one-loop-induced flavour structure, possibly generating the small ratio $\Delta m_{\rm solar}^2/\Delta m_{\rm atm}^2$ dynamically.