Gluonic effects in eta and eta-prime physics

We review the theory and phenomenology of the axial U(1) problem with emphasis on the role of gluonic degrees of freedom in eta and eta' production processes, especially the low-energy pN -> pN eta and pN -> pN eta' reactions.Comment: 20 pages, 2 figures, Invited talk at the WASA Workshop on Eta Physics, October 2001, Uppsala, Swede

Neutrinos from spin dynamics

We conjecture that neutrino physics might correspond to the spontaneous magnetisation phase of an Ising-like spin model interaction coupled to neutrino chirality which operates at scales close to the Planck mass. We argue that this scenario leads to a simple extension of the Standard Model with no additional parameters that dynamically generates parity violation and spontaneous symmetry breaking for the gauge bosons which couple to the neutrino. The neutrino mass in the model ~ (the electroweak scale)^2 / 2M where M is the scale of the ``spin-spin'' interaction. For the ground state of the model the free energy density corresponding to the cosmological constant is ~ the neutrino mass, consistent with observation.Comment: 9 page