Z=50 shell gap near 100^{100}Sn from intermediate-energy Coulomb excitations in even-mass 106−−112^{106--112}Sn isotopes

Rare isotope beams of neutron-deficient $^{106,108,110}$Sn nuclei from the fragmentation of $^{124}$Xe were employed in an intermediate-energy Coulomb excitation experiment yielding $B(E2, 0^+_1 \to 2^+_1)$ transition strengths. The results indicate that these $B(E2,0^+_1 \to 2^+_1)$ values are much larger than predicted by current state-of-the-art shell model calculations. This discrepancy can be explained if protons from within the Z = 50 shell are contributing to the structure of low-energy excited states in this region. Such contributions imply a breaking of the doubly-magic $^{100}$Sn core in the light Sn isotopes.Comment: 4 pages, 4 figure

The Carbon Dioxide Laser Induced Decomposition of Freon 113

The carbon dioxide laser irradiation of Freon 113, 1,1,2 trichlorotrifluoroethane, yielded Freons 11, trichloro­fluoromethane, l2, dichlorodifluoromethane, and 13, chloro­trifluoromethane, along with chlorotrifluoroethylene and unidentified products. Product formation was found to increase as the pressure of the starting material and laser power were increased, although no formal pressure or power dependenry could be determined. The Freon products were identified using a gas chromatograph in the flame ionization mode with a molecular sieve column. Chlorotrifluoroethylene was identified with an infrared spectrophotometer. The buildup of unidentifiPd brown tars was observed on the glass walls of irradiated cells. The pyroysis of Freon 113 has not been thoroughly studied, although chlorotriflouroethylene is known tc be a pyrolytic product. It is proposed that the laser induced products may be similar to the pyrolytic products

Shape and structure of N=Z 64Ge; Electromagnetic transition rates from the application of the Recoil Distance Method to knock-out reaction

Transition rate measurements are reported for the first and the second 2+ states in N=Z 64Ge. The experimental results are in excellent agreement with large-scale Shell Model calculations applying the recently developed GXPF1A interactions. Theoretical analysis suggests that 64Ge is a collective gamma-soft anharmonic vibrator. The measurement was done using the Recoil Distance Method (RDM) and a unique combination of state-of-the-art instruments at the National Superconducting Cyclotron Laboratory (NSCL). States of interest were populated via an intermediate-energy single-neutron knock-out reaction. RDM studies of knock-out and fragmentation reaction products hold the promise of reaching far from stability and providing lifetime information for excited states in a wide range of nuclei

Two-neutron transfer reaction mechanisms in 12^{12}C(6^6He,4^{4}He)14^{14}C using a realistic three-body 6^{6}He model

The reaction mechanisms of the two-neutron transfer reaction $^{12}$C($^6$He,$^4$He) have been studied at 30 MeV at the TRIUMF ISAC-II facility using the SHARC charged-particle detector array. Optical potential parameters have been extracted from the analysis of the elastic scattering angular distribution. The new potential has been applied to the study of the transfer angular distribution to the 2$^+_2$ 8.32 MeV state in $^{14}$C, using a realistic 3-body $^6$He model and advanced shell model calculations for the carbon structure, allowing to calculate the relative contributions of the simultaneous and sequential two-neutron transfer. The reaction model provides a good description of the 30 MeV data set and shows that the simultaneous process is the dominant transfer mechanism. Sensitivity tests of optical potential parameters show that the final results can be considerably affected by the choice of optical potentials. A reanalysis of data measured previously at 18 MeV however, is not as well described by the same reaction model, suggesting that one needs to include higher order effects in the reaction mechanism.Comment: 9 pages, 9 figure

Parsing and Managing Inconsistency in Investor-State Dispute Settlement

Inconsistency in legal interpretation is among the most salient problems in investor-state dispute settlement (ISDS). Some such instances have been particularly glaring, and introducing consistency into ISDS rates high on the agenda of reformers - particularly for several government delegations leading multilateral reform efforts in the United Nations Commission on International Trade Law (UNCITRAL) Working Group III. This Article starts from the position that some degree of interpretive inconsistency is endemic to any legal order. Yet systemic inconsistency tends to undermine the basic purposes of the investment treaty regime – namely protecting and promoting foreign direct investment through predictable international legal rules and institutions. With an eye to reform, seek to parse the problem of inconsistency at a more granular level, in order to distinguish between types of norms where a degree of inconsistency is (relatively) manageable and (potentially) tolerable, and those where inconsistency is unacceptable. In this regard, we focus on two key distinctions: between (1) rules and standards, and (2) norms of conduct and structural “rules of the game.” Although inconsistency is always problematic, we suggest that it is in this later category (rules of the game) where inconsistency is most destructive