Parity violation in the γ-decay of polarized 93Tc^{93}Tc nuclei in the 17/2−17/2^- isomeric state

none20We report on a determination of the parity nonconserving (PNC) matrix element in the bound parity doublet of 93Tc. The experiment was carried out at the GSI, Darmstadt and LNL, Legnaro laboratories. The recoil-mass-separated radioactive beam of 93Tc nuclei in the isomer, following a fusion-evaporation reaction, was polarized by the tilted-foil method and the resulting 0°–180° γ asymmetry with respect to the induced polarization direction was measured by two large-volume Ge detectors. The measured γ asymmetry of 3-σ significance, Aγ = 8.4(2.7) · 10−4, yields a matrix element of . This experimental result is c microscopic calculations based on the DDH “best value” interaction for the nuclear weak Hamiltonian. We discuss our results and their significance with respect to the existing data regarding PNC effects in bound nuclear systems.noneM. Hass;C. Broude;L. Weissman;L. Müller;G. Montagnoli;F. Scarlassara;G.F. Segato;C. Signorini;G. Goldring;D. Ackermann;P. Bednarczyk;L. Corradi;P. Spolaore;M. Lindroos;S. Hormann;V. Ninov;F.P. Hessberger;F. Soramel;N. Takahashi;B.A. BrownM., Hass; C., Broude; L., Weissman; L., Müller; Montagnoli, Giovanna; Scarlassara, Fernando; Segato, Gianfranco; Signorini, Cosimo; G., Goldring; D., Ackermann; P., Bednarczyk; L., Corradi; P., Spolaore; M., Lindroos; S., Hormann; V., Ninov; F. P., Hessberger; Soramel, Francesca; N., Takahashi; B. A., Brow

Strong reaction channels at barrier energies in the system 6Li{^{6}Li} + 208Pb{^{208}Pb}

Large cross-section reaction channels were measured in the systems ${^{6}Li}$(${^{7}Li}$) + ${^{208}Pb}$ with high statistical accuracy at 5(3) energies around the Coulomb barrier from 29 to 39 MeV. These channels were assigned (mainly) to the breakup of ${^{6}Li}$, very loosely bound, into $\alpha$ + d and to the breakup of ${^{5}Li}$, produced by n-transfer to the target, into $\alpha$ + p and to similar processes with ${^{7}Li}$ beam. The cross-sections with ${^{6}Li}$, $S_{\alpha}$ = 1.475 MeV, are systematically larger than the ${^{7}Li}$ ones. This reflects, most likely, the higher binding energy of ${^{7}Li}$, $S_{\alpha}$ = 2.468 MeV. Theoretical predictions for the ${^{6}Li}$ + ${^{208}Pb}$ system which include for ${^{6}Li}$ breakup to continuum states within a continuum discretized coupled-channels approach (CDCC) and resonant breakup plus n-transfer with DWBA reproduce the angular distribution shapes but still underestimate the cross-sections by a factor ~ 3

Study of very neutron deficient nuclei 178^{178}Pt and 181^{181}Au

The $^{178}$Pt and $^{181}$Au nuclei have been studied with the (230 MeV) $^{46}$Ti + $^{142}$Nd fusion-evaporation reaction; $\gamma$-rays, evaporated particles and recoiling nuclei have been detected by the $\gamma$-array GASP + the Si ball ISIS + the recoil mass spectrometer RMS. The newly observed structures in $^{178}$Pt and $^{181}$ Au are most probably built on the proton and quasi-proton h$_{9/2}$ and i$_{13/2}$ configurations