Three-triplet realisations of gauge models and deep-inelastic scattering

We investigate the predictions for very-high-energy inelastic neutrino scattering of three-triplet realisations of the weak-interaction gauge theories based on the groups O(3) and SU(2) × U(1).     

A universal tunnelling coefficient for step- and graded-index multimode fibres

A single expression is presented for the power transmission coefficient of both step- and graded-index fibres, which is uniformly valid for all weakly tunnelling and refracting rays. Its accuracy is demonstrated in a comparison of the corresponding power attenuation coefficient for the step-index fibre with solutions to the electromagnetic boundary value problem.     

A test of the DWIA at 135 MeV using the 207Pb(p,p′) reaction

Data for the excitation of the strongly collective octupole doublet in ²⁰⁷Pb at E_X = 2.64 MeV is used to test the distorted wave impulse approximation (DWIA) at a proton bombarding energy of 135 MeV. A complex, effective local interaction derived from the nucleon-nucleon phase shifts is used together with the wave functions of Ring and Speth for the low-lying octupole state in ²⁰⁸Pb. The DWIA (including central and spin-orbit terms) is found to be in reasonable agreement with both the magnitude and shape of the observed cross section.     

Neutral weak currents and the proton-neutron mass difference

The logarithmically divergent contributions to the proton-neutron mass difference arising from the exchange of intermediate vector bosons are investigated. Within the framework of Weinberg's model we find a divergent contribution of opposite sign to the electromagnetic divergence which is, however, insufficient to cancel it completely.     

Spinning solutions of classical Yang-Mills theory

A class of 0(4)-covariant solutions is found to Yang-Mills field equations in Minkowski space. The solutions have finite energy, contain the 0(4)-invariant solutions including the meron as special cases, and have an unexpected new feature: they possess angular momentum. Their physical properties are examined and numerical solutions are displayed graphically.     

Metastability of native proteins and the phenomenon of amyloid formation

An experimental determination of the thermodynamic stabilities of a series of amyloid fibrils reveals that this structural form is likely to be the most stable one that protein molecules can adopt even under physiological conditions. This result challenges the conventional assumption that functional forms of proteins correspond to the global minima in their free energy surfaces and suggests that living systems are conformationally as well as chemically metastable.