Question of low-lying intruder states in Be-8 and neighboring nuclei

The presence of not yet detected intruder states in Be-8, e.g., a J = 2(+) intruder at 9 MeV excitation would affect the shape of the beta(-/+)-delayed alpha spectra of Li-8 and B-8. In order to test the plausibility of this assumption, shell-model calculations with up to 4 (h) over bar omega excitations in Be-8 (and up to 2 (h) over bar omega excitations in Be-10) were performed. With the above restrictions on the model spaces, the calculations did not yield any low-lying intruder state in Be-8. Another approach-the simple deformed oscillator model with self-consistent frequencies and volume conservation-gives an intruder state in 8Be which is lower in energy than the above shell-model results, but its energy is still considerably higher than 9 MeV.This work was supported by Department of Energy Grant No. DE-FG02-95ER40940, by DGICYT -Spain grants under Contracts No. PB95/0123 and SA95-0371.Peer reviewe

Thermal stress and acid-base balance in dairy cattle.

Missouri Agricultural Experiment Station and the United States Department of Agriculture cooperating."This bulletin is a report on the Department of Dairy Husbandry research project number 125, 'Climatic Factors'"--P. [2].Digitized 2007 AES.Includes bibliographical references (page 27)

Relativistic many-body calculations of energies of n=3 states in aluminumlike ions

Energies of 3l3l′3l″ states of aluminumlike ions with Z=14?100 are evaluated to second order in relativistic many-body perturbation theory starting from a 1s22s22p6 Dirac-Fock potential. Intrinsic three-particle contributions to the energy are included in the present calculation and found to contribute about 10?20 % of the total second-order energy. Corrections for the frequency-dependent Breit interaction and the Lamb shift are included in lowest order. A detailed discussion of contributions to the energy levels is given for aluminumlike germanium (Z=32). Comparisons are made with available experimental data. We obtain excellent agreement for term splitting, even for low-Z ions. These calculations are presented as a theoretical benchmark for comparison with experiment and theory

Oriented chlorine atoms as a probe of the nonadiabatic photodissociation dynamics of molecular chlorine

Molecular chlorine was photolyzed using circularly polarized radiation at 310 and 330 nm, and orientation moments of the chlorine-atom Cl(P-2(j)) photofragment distributions were measured by resonance enhanced multiphoton ionization using circularly polarized light with Doppler resolution. The product atoms were found to be strongly oriented in the laboratory as a result of both incoherent and coherent dissociation mechanisms, and the orientation moments contributed by each of these mechanisms have been separately measured. The experimental results can be explained by nonadiabatic transitions from the C (1)Pi (1u) state to higher states of Omega =1(u) symmetry, induced by radial derivative coupling. Ab initio calculations indicate strong Rosen-Zener-Demkov noncrossing-type radial derivative couplings between states of 1(u) symmetry. The observed angular distribution (beta parameter) indicates that 88% of Cl*(P-2(1/2)) fragments produced at 310 nm originate from a perpendicular transition to the C state. The orientation measurements suggest that 67 +/- 16% of Cl-35*(P-2(1/2)) atoms dissociate via the 1(u)((3)Sigma (+)(1u)) state, and 21 +/-6% dissociate via the 1(u)((3)Delta (1u)) state. (C) 2000 American Institute of Physics. [S0021-9606(00)01444-6].</p

Odderon and spin dependence of high energy proton-proton scattering

The sensitivity of the spin dependence of high energy pp scattering, particularly the asymmetry A_{NN}, to the odderon is demonstrated. Several possible ways of determining the spin dependence of the odderon coupling from small-t data are presented.Comment: Figure corrected, some references modified and some minor changes to tex