Sideband and quantum-beat measurements with129mTe and57Co sources

Sideband intensities and quantum beats were measured for recoillessly emitted gamma rays as a function of the vibration frequency of quartz crystals on which sources of^129mTe and⁵⁷Co were deposited. At most frequencies a low degree of coherence of the vibrations of the source nuclei was observed.     

Interactions between colloidal particles in simple shear flow

Recent progress in experimental and theoretical developments dealing with colloidal. interactions between two spheres in shear flow is reviewed. A systematic comparison is made between spheres suspended in simple electrolyte and in cationic polyelectrolye solutions. Microrheological observations, performed with the traveling microtube, make an in-depth investigation possible of the colloidal forces and the mechanisms of polymer bridge formation. Reasons are discussed for the often-observed aging of colloidal aggregates. Finally, coagulation rates are presented for systems with weak and strong Brownian motion. It is shown that the often-used assumption of additivity of the ortho- and perikinetic coagulation rates is incorrect.     

Spin dependency of optical feeding into the Ē(2E) metastable doublet of ruby

An analysis has been made of spin polarization memory in the ē(²E) metastable doublet of Cr³⁺ in Al₂O₃ upon broadband optical pumping with unpolarized light. Coefficients describing the relative feeding rates of all four ⁴A₂ ground-state levels into the two ē(²E) levels have been obtained. The optical pumping cycle appears to contain a component with Δm_S=±2.     

The laws of relativistic thermodynamics: III. The entropy law

The covariant entropy law is derived for an arbitrary choice of the hydrodynamic velocity field. The effects of the choices of Eckart and of Landau and Lifshits are shown.     

SupersymmetricSU (11), the invisible axion,and proton decay

We supersymmetrize the very attractive flavour unification modelSU (11). As with other supersymmetric GUTs the gauge hierarchy problem is simplified, but we may also have observable (τ _p ≈10³³ yrs) proton decay. The required split multiplets are obtained by making the adjoint take a particular direction. Supersymmetry is broken softly at the TeV scale. There is a uniqueU(1) _A symmetry, and hence there are no true Nambu-Goldstone bosons. TheU(1) _A is broken at the GUT scale and there result an invisible axion and neutrino masses.     

The reaction 36S(p, γ)37Cl: (II). Lifetimes,spins and parities of 37Cl levels

Analysis of the γ-ray angular distributions measured at 16 ³⁶S(p, γ)³⁷Cl resonances yields the spins and/or parities of 21 bound states of ³⁷Cl in addition to the resonance spins. Among the latter are four $\text{J =}\text{1}\text{2}$ resonances. For several other bound states the possible spins have been restricted. Multipolarity mixing ratios have been deduced from the same data. Lifetimes (or lifetime limits) of 29 bound states have been deduced from DSA measurements.This extensive experimental information allows a comparison with the results of a shell-model calculation for both the even- and odd-parity states of ³⁷Cl. In this calculation either zero, one or two particles are promoted from the 2s_{$\text{1}\text{2}$} or 1d_{$\text{3}\text{2}$} to the 1f_{$\text{7}\text{2}$} or 2p_{$\text{3}\text{2}$} subshells. Up to an excitation energy of about 5 MeV a one-to-one correspondence is found between experimental and calculated levels.