Shape transition in light Pt isotopes: Magnetic moments and electric quadrupole moment ratios for185,187,189Pt

Nuclear orientation and nuclear magnetic resonance experiments were performed on^{185, 187, 189}Pt isotopes oriented in Fe and single crystal Zn at temperatures down to about 6 mK. The hyperfine splitting frequencies of¹⁸⁵Pt and¹⁸⁷Pt in iron were determined to be 164.9(2) and 261.1(2) MHz, respectively. With the hyperfine field of −126.1(2.5) T, the g-factors are deduced to be |g(¹⁸⁵Pt)|=0.172(3) and |g(¹⁸⁷Pt)|=0.272(5). The spectroscopic quadrupole moment of¹⁸⁷Pt was found to be negative with magnitude similar to that of¹⁸⁹Pt, indicating a predominantly oblate ground state deformation for both isotopes. The spectroscopic quadrupole moment of¹⁸⁵Pt was found to be positive, with the ratio Q(¹⁸⁵Pt)/Q(¹⁸⁹Pt)=−3.6(9), clearly indicating a change to prolate ground state deformation.     

Magnetic dipole moments near Sn: Measurement on isomeric 11/2 states in odd-A Te and Te by NMR/ON

On-line low temperature nuclear orientation (OLNO) experiments have been performed on the odd-A Te isotopes ¹³¹Te and ¹³³Te using the technique of nuclear magnetic resonance on oriented nuclei (NMR/ON). The magnetic moments of the isomeric 11/2⁻ states have been measured extending the known data on these states in the Te isotopes up to the neutron shell closure at N = 82. The contribution to the 11/2⁻ magnetic moment in ¹³³Te due to core polarisation is calculated using an RPA shell model as well as corrections to the magnetic dipole operator caused by mesonic exchange currents. The neutron number dependence of the magnetic moments of the 11/2⁻ isomers in heavy Te isotopes is discussed in terms of particle-core coupling model (PCM) calculations.     

Self-consistent Green’s function formalism for acoustic and light scattering. Part 3: Unitarity and symmetry

This paper completes two previous papers in which we have developed the self-consistent Green’s function formalism for acoustic and light scattering. It is concerned with the unitarity and symmetry properties of the interaction and far field scattering operator of this formalism. We will show that these are primarily mathematical properties, and that the principles of energy conservation and reciprocity, which express our physical experience, can be modeled by these mathematical properties. For this we have to distinguish two experimental configurations, and only one of these configurations will allow us to relate energy conservation to unitarity. Closely related to this are questions concerning the definition and measurability of the scattering quantities and the importance of the optical and generalized optical theorem. These questions will be also discussed from the point of view of the self-consistent Green’s function formalism.     

Quantum cosmology in 2+1 and 3+1 dimensions

We study the Wheeler-DeWitt equations for the wave function of the universe in 2+1 and 3+1 dimensions. Perturbation methods are developed and the first few orders areexplicitly calculated for the case of an inflating universe. We find that early quantum fluctuation can produce large-scale inhomogenities in the global structure of the universe at later times.     

Synthetic applications of the tandem aldol condensation-radical cyclization sequence. A new and highly convergent method for the annulation of carbocycles

The sequential treatment of α,β-unsaturated ketones with (phenylseleno)alanes or titanates followed by representative β,γ-unsaturated aldehydes has been shown to furnish β-(phenylseleno)ketols in high yield. The reductive cyclization of these species in the presence of tri-$\text{n}$-butyltin hydride affords the corresponding condensed carbocycles with high efficiency.     

The parabolic rule,the Pandya transformation,and the structure of100In

The Pandya transformation and the Paar parabola rule are used to predict the level structure of particle-hole¹⁰⁰In from the known levels of particle-particle⁹²Nb.The authors wish to express their appreciation to the U.S. Department of Energy for the support of this work.     

He I photoelectron spectra of [3]-ferrocenophane and its 7-oxa derivative

He I photoelectron spectra of [3]-ferrocenophane and 6,8-dimethyl-7-oxa-[3]-ferrocenophane have been measured. In comparison with ferrocene the energy gap between ²E′₂(a′₁²e′₂³) and ²A′₁(a′₁¹e′₂⁴) is decreased to 0.28 and 0.22 eV due to the destabilization of the a′₁(d)-level originating in its more pronounced mixing with ligand orbitals. The increase of photoionization cross section of the a′₁(d)-level in the 6,8-dimethyl-7-oxa-[3]-ferrocenophane spectrum supports this interpretation. The band shapes and ionization potentials of ligand π-levels are strongly influenced by the hydrocarbon bridge.     

Perturbation of the Laplacian supported by null sets,with applications to polymer measures and quantum fields

We discuss hamiltonians in L²(R^d, dx) of the form H = ?Δ + V, with V a potential supported by a zero measure set C. In particular if C is a path of a brownian motion b such that V(x) = ∫₀¹λ(x, ω)δ(x-b(s, ω)) ds, we show that H exists as a nontrivial, self-adjoint, lower bounded perturbation of ?Δ when d ?5. We must choose λ to be an infinitesimal, negative function for d = 4,5, but for d ? 3 any bounded real-valued function λ will do. The connection with Edward's model of polymers as well as with quantum fields of the ?_d⁴-type is also discussed. The proofs use methods of nonstandard analysis.     

Nuclear orientation and coincidence studies of118I and118Cs isotopes

Gamma-gamma coincidence and on-line nuclear orientation experiments have been done on¹¹⁸I^g(2–),¹¹⁸I^m(7–),¹¹⁸Cs^g(2–) and¹¹⁸Cs^m(8–). The activities were produced by 175 MeV^32,34S beams on⁹³Nb and the products passed through an isotope separator. Nuclear moments for the¹¹⁸I isomers are deduced. The decay scheme of¹¹⁸Te is given and various spin assignments made, particularly 1944.3 KeV (3–) and 957.3 KeV (o⁺). Equilibrium distortion of the¹¹⁸I ground state is discussed briefly.