No abstract

No abstract

Abstract:The IUPAC/IUPAP Joint Working Party (JWP) on the priority of claims to the discovery of new elements 113-116 and 118 has reviewed the relevant literature pertaining to several claims. In accordance with the criteria for the discovery of elements previously established by the 1992 IUPAC/IUPAP Transfermium Working Group (TWG), and reinforced in subsequent IUPAC/IUPAP JWP discussions, it was determined that the Dubna-Livermore collaborations share in the fulfillment of those criteria both for elements Z = 114 and 116. A synopsis of experiments and related efforts is presented.

the exact wave function zfz from the truncated representation for g, i.e. , what is V,qq if (1 -PgV, tt) P= 0 yields the exact wave function given in Kq. (51). Since we can write Kq. (52) as S=PgVL1/(1 gQV-) j4 and using the calculable expression for (1 -gQV) from Kq. (51), we obtain P= PgV(1+Gpl) [1/(1+GpPl GprtpGoQl)]fWe then see that the effective operator which permits the use of a truncated representation for g, and yet yields the exact wave function, is V,tt= t[1/(1+GoPt GortsG-oQt) g.Neglecting the compact operator in the denominator of V ff we see that the wave function should again be approximately calculated from the lowest-order term:Q~Pgtf.We see that the t operator of the residual interaction rather than the residual interaction potential is the one that appears in a convergent formulation of three-body shell-model calculations if only a finite set of basis states, Pf, is used in the diagonalization of the residual interaction. Calculations that use an approximation for the t matrix have recently been performed by Hodgson. "He finds that there is no definite improvement over a calculation that just employs the potential. Kuo and Brown" make use of the second Born term in the series for t, i.e. , t V+VGpV. They use core polarization states in the intermediate states of the term VGOV. This implies that Kuo and Brown have included a structure in the core and have departed from a strict three-body shell-model interpretation of the problem.At any rate, they find the second Born term to be important."R.A detailed study of the wave properties of the nuclear optical model is presented to elucidate the problem of barrier penetration by charged particles and to remove some of the mystique of optical-model calculations. The wave properties and the concomitant penetration are most straightforward for square wells, for which the resonance, reflection, and penetration are easily ascribed to separate factors. We show that the wave properties of more general diffuse-edge optical potentials achieve a similar simplicity by the construction of an equivalent square well (ESW) which has the same resonance, penetration, and absorption factors as the optical potential, but which differs in its reflection factor. A general construction of the ESW is given, and we apply it to the following problems: (1) the very narrow single-particle resonances of real optical potentials that occur at energies far below the Coulomb barrier, (2) the nuclear absorption cross sections in the presence of barriers, (3) the calculation of absorption cross sections at astrophysical energies (extreme barrier penetration) employing optical models fitted to data at higher energies, and (4) the value of the nuclear radius and sum-rule limits appropriate to the analysis of nuclear reactions. In some cases of extreme barrier penetration, the ESW fails to yield all the properties. For example, cases are described where the bulk of the absorption may attain in the distant "tail" of the imaginary term in the optical potential: The corresponding reaction ra...

Republication or reproduction of this report or its storage and/or dissemination by electronic means isAbstract: The IUPAC/IUPAP joint working party on the priority of claims to the discovery of elements 110, 111, and 112 has reviewed the relevant literature pertaining to the several claims. In accordance with the criteria for the discovery of elements, previously established by the 1992 IUPAC/IUPAP Transfermium Working Group, it was determined that the claim by the Hofmann et al. research collaboration for the discovery of element 110 at GSI has fulfilled those criteria. For elements 111 and 112, the collaboration of Hofmann et al. produced highquality data with plausible interpretations, but confirmation by further results is needed to assign priority of discovery for these elements. The working party was not convinced that claims of other collaborations have satisfied the discovery criteria.