Implications of the JHF-Kamioka neutrino oscillation experiment

After quickly reviewing the existing evidence for neutrino oscillations, I summarise the goals and capabilities of the JHF-Kamioka long baseline superbeam experiment. Theoretical implications of what this experiment could potentially discover are then discussed.Comment: 10 pages, 3 figures, LaTeX, ws-procs9x6.cls. Invited talk at the Workshop on Physics at the Japan Hadron Facility (JHF), Adelaide, 14-21 March 200

The brane as a Higgs domain wall: ideas and issues

The most obvious field-theoretic model for a brane is a scalar field domain wall or kink. I discuss how this idea can be connected with spontaneous internal symmetry breaking via a mechanism called the ``clash of symmetries''. Compatibility with Randall and Sundrum's warped metric alternative to compactification is then demonstrated. I end with brief remarks about open questions.Comment: 4 pages. Invited talk at Susy06. To appear in the proceeding

Generalised leptonic colour

It is conceivable that there is an $SU(N)_{\ell}$ `colour' gauge group for leptons, analogous to the gauged $SU(3)_q$ colour group of the quarks. The standard model emerges as the low energy effective theory when the leptonic colour is spontaneously broken. The simplest such generalised leptonic colour models are constructed. We show that the see-saw mechanism for small neutrino masses, along with the theoretical constraint of electric charge quantisation, suggests that the models with $N = 3, 5, 7$ are the theoretically most promising cases. A striking feature of generalized leptonic colour is the physics associated with the extra leptonic degrees of freedom -- the liptons. These particles can potentially be discovered at future colliders, such as the LHC, making the idea testable in the near future.Comment: about 7 page