Precise half-life measurement of the superallowed β+ emitter 10C
The half-life of '°C has been measured to be 19.310(4) s, a result with 0.02% precision, which is a factor of three improvement over the best previous result. Since 10 C is the lightest superallowed 0 + → 0 + β + emitter, its ft value has the greatest weight in setting an upper limit on the possible presence of scalar currents.
High-precision Half-life And Branching Ratio Measurements For Superallowed β+ Emitters At TRIUMF-ISAC
High precision measurements of the $ft$ values for superallowed Fermi $\beta$ transitions between $J^\pi~=~0^+$ isobaric analogue states allow for stringent tests of the electroweak interaction described by the Standard Model. These transitions provide an experimental probe of the Conserved-Vector-Current hypothesis, enable the most precise determination of the up-down ($V_{ud}$) element of the Cabibbo-Kobayashi-Maskawa quark-mixing matrix, and allow one to set stringent limits on the existence of scalar currents in the weak interaction. 
An extensive program of superallowed branching-ratio and half-life measurements at TRIUMF's Isotope Separator and Accelerator (ISAC) facility has covered the full range of superallowed emitters, from the lightest case, $^{10}$C, to the heaviest case for which precision data are currently available, $^{74}$Rb. These experiments have been performed using a 4$\pi$ continuous-flow gas proportional $\beta$ counter, the 8$\pi$ $\gamma$-ray spectrometer, and, most recently, the new high-efficiency GRIFFIN $\gamma$-ray spectrometer. In this paper, recent highlights from the superallowed Fermi $\beta$ decay program at TRIUMF will be summarized, including high-precision half-life measurements for all three of the lightest superallowed emitters, $^{10}$C, $^{14}$O, and $^{18}$Ne, with the greatest sensitivity to a potential weak scalar current contribution, as well as high-precision branching-ratio measurements for the heavy superallowed emitters $^{62}$Ga and $^{74}$Rb.
Étude de la résonance géante des noyaux légers et moyens par diffusion du rayonnement de freinage
Les sections efficaces differentielles de diffusion photonucleaire ont ete mesurees dans la region de la resonance geante pour les noyaux 9Be, 10B, 11B, 12C, 14N, 16O, 19F 23Na, 24Mg, 28Si, 32S, 39K, 40 Ca, 55Mn, 56Fe, 59CO. Pour beaucoup de ces noyaux, on observe des niveaux ou groupes de niveaux situes au-dessus de la resonance geante vers 28-30 MeV. Des mesures de repartitions angulaires ont permis d'evaluer la contribution de la diffusion inelastique vers le premier niveau 2+ des noyaux 24Mg, 28Si, 56Fe. Ces memes mesures indiquent une forte interference des differents etats de spin des niveaux excites par transition dipolaire pour 39K et au-dessus de 25 MeV pour 23Na.