Etude des états excités 2+ de noyaux pairs-pairs peuplés par des transitions Bêta. Effet de l'environnement atomique sur la corrélation directionnelle Bêta-Gamma.

Docteur en Sciences -- Université catholique de Louvain, 196

Optimization of the Recoil-direction-sensitive Target for Muon-capture

The optimal thickness of layers composing nucleus-recoil-sensitive target that enables the measurement of a particular orientation parameter of the final nuclei B-12(gs)(I = 1(+)) and N-16(gs)(I = 2(-)) in the reactions mu(-) + C-12(0(+)) --> upsilon(mu) + B-12(gs)(I = 1(+)) and mu(-) + O-16(0(+)) --> upsilon(mu) + N-16(gs)(I = 2(-)) is estimated according to the current status of art of the slowing down of low energy (recoil energy of B-12 is 376 keV and that of N-16 is 300 keV) charged particles in matter. The choice of materials for orientation preserving (Ni, Ag, Rh) and for orientation-destroying (Al) layers which sandwich the production target layer C or BeO is based on the data obtained with polarized B-12 and N-13 radioactive nuclei beams at the Universite Catholique de Louvain

Comparison of the /sup 16/N/sup m/(O/sup -/) beta -decay rate with the inverse muon-capture rate: the induced pseudoscalar form factor in nuclei

An experiment to measure the rate lambda /sub beta / of the weak decay /sup 16/N/sup m/(O/sup -/, 120 keV) rarr /sup 16/O(O/sup +/, g.s.)+ beta /sup -/+ nu macr is described. The results are combined with the rate lambda /sub mu / for the inverse reaction mu /sup -/+/sup 16/O(O/sup +/, g.s.) rarr /sup 16/N /sup m/(O/sup -/, 120 keV)+ nu mu to yield a value for g/sub p/ the inverse-pseudoscalar form factor. The result suggests an upward renormalisation.Anglai

Macroscopic polarization signals with stopped muons

The authors point out the merits of macroscopic polarization signals known as Hanle signals, generated with stopped polarized muons.Anglai