The\overrightarrow p - Si elastic scattering in the region of giant multipole resonances

Analyzing powers and cross sections for the scattering of polarized protons from Si have been measured at eight energies between 17 and 29MeV. The analysing powers show an “anomalous” behaviour and an optical model analysis yields a non-monotonic effect in the spin-orbit potential.     

α + α scattering phase shifts and values of the reaction cross section near threshold of the 7Li + p and 7Be + n channels

The most recent values of the reaction cross section σ_R published in this journal are not well established and the reasons invoked to discard previous values are shown to be erroneous. In addition, a reanalysis of full angular distributions confirms the complex phase shifts obtained by the present author and the corresponding values of σ_R.     

Proton polarization and differential cross section for the (3He,p) reaction on 6Li and 9Be at 14 MeV

Angular distributions of the proton polarization and the differential cross section have been measured for the reaction (³He, p) initiated by 14 MeV incident ³He particles and proceeding to the ground and the first excited states of the final nuclei ⁸Be and ¹¹B. Large polarization values were observed, especially for the ⁹Be(³He, p)¹¹B reaction leading to both the ground and the first excited states in ¹¹B. The experimental results have been analysed in terms of a two-nucleon transfer spindependent distorted-waves theory using finite-range formalism and including corrections due to the non-locality of the optical potentials. A proper coherent summation over L and S, whenever necessary was included in the DWBA calculations of the polarization and the differential cross section as implied by the presence of the spin-orbit terms in the optical-model potentials used to generate the distorted waves.     

Fractal aggregates in simulated reduced gravity

We have developed a study of fractal aggregates in the laboratory geared towards their final production in a microgravity environment, on board of space shuttles and stations. Floating particles in gases and fluids have allowed simulation of conditions in reduced gravity. Production methods and dimensional analysis are described.     

The reaction 2H(α,αp)n near threshold and excited states of 6Li

The reaction ²H(α,αp)n has been studied in a kinematically complete experiment between E_α=9.22 and 11.3 MeV (3.07 to 3.77 MeV in the CM system). Data at the highest energies are dominated by αp and αn final-state interactions and at the same time indicate the relevance of the broad state (J^π=2⁺, T=0) centered at 4.7 MeV in ⁶Li ignored heretofore in theoretical calculations. Possible effects due to three-body forces are discussed.     

Asymétrie du temps: Polarisation et pouvoir d'analyse dans les réactions nucléaires

Measurements of the proton polarization in the reactions ⁷Li(³He, $\text{p}$)⁹Be and ⁹Be(³He, $\text{p}$)¹¹B and of the analyzing powers of the inverse reactions, initiated by polarized protons at the same c.m. energies, show significant differences which imply the failure of the polarization-analyzing-power theorem and, prima facie, of time-reversal invariance in these reactions. The reaction ²H(³He, $\text{p}$)⁴He and its inverse have also been investigated and show some smaller differences. A discussion of the instrumental asymmetries is presented.