Attosecond time-scale multi-electron collisions in the Coulomb four-body problem: traces in classical probability densities

In the triple ionization of the Li ground state by single photon absorption the three electrons escape to the continuum mainly through two collision sequences with individual collisions separated by time intervals on the attosecond scale. We investigate the traces of these two collision sequences in the classical probability densities. We show that each collision sequence has characteristic phase space properties which distinguish it from the other. Classical probability densities are the closest analog to quantum mechanical densities allowing our results to be directly compared to quantum mechanical results.Comment: 9 pages, 10 figure

Co-infection with Onchocerca volvulus and Loa loa microfilariae in central Cameroon: are these two species interacting?

Ivermectin treatment may induce severe adverse reactions in some individuals heavily infected with Loa loa. This hampers the implementation of mass ivermectin treatment against onchocerciasis in areas where Onchocerca volvulus and L. loa are co-endemic. In order to identify factors, including co-infections, which may explain the presence of high L. loa microfilaraemia in some individuals, we analysed data collected in 19 villages of central Cameroon. Two standardized skin snips and 30 mul of blood were obtained from each of 3190 participants and the microfilarial (mf) loads of both O. volvulus and L. loa were quantified. The data were analysed using multivariate hierarchical models. Individual-level variables were: age, sex, mf presence, and mf load; village-related variables included the endemicity levels for each infection. The two species show a certain degree of ecological separation in the study area. However, for a given individual host, the presence of microfilariae of one species was positively associated with the presence of microfilariae of the other (OR=1.79, 95% CI [1.43-2.24]). Among individuals harbouring Loa microfilariae, there was a slight positive relationship between the L. loa and O. volvulus mf loads which corresponded to an 11% increase in L. loa mf load per 100 O. volvulus microfilariae. Co-infection with O. volvulus is not sufficient to explain the very high L. loa mf loads harboured by some individuals

General Concentric Black Rings

Supersymmetric black ring solutions of five dimensional supergravity coupled to an arbitrary number of vector multiplets are constructed. The solutions are asymptotically flat and describe configurations of concentric black rings which have regular horizons with topology $S^1 \times S^2$ and no closed time-like curves at the horizons.Comment: 8 pages, minor alterations, typos corrected. Version to be published in PR

Spatial properties of entangled photon pairs generated in nonlinear layered structures

A spatial quantum model of spontaneous parametric down-conversion in nonlinear layered structures is developed expanding the interacting vectorial fields into monochromatic plane waves. A two-photon spectral amplitude depending on the signal- and idler-field frequencies and propagation directions is used to derive transverse profiles of the emitted fields as well as their spatial correlations. Intensity spatial profiles and their spatial correlations are mainly determined by the positions of transmission peaks formed in these structures with photonic bands. A method for geometry optimization of the structures with respect to efficiency of the nonlinear process is suggested. Several structures composed of GaN/AlN layers are analyzed as typical examples. They allow the generation of photon pairs correlated in several emission directions. Photon-pair generation rates increasing better than the second power of the number of layers can be reached. Also structures efficiently generated photon pairs showing anti-bunching and anti-coalescence can be obtained. Three reasons for splitting the correlated area in photonic-band-gap structures are revealed: zig-zag movement of photons inside the structure, spatial symmetry and polarization-dependent properties. Also spectral splitting can be observed in these structures.Comment: 13 pages, 17 figure

Magnetic moments of octet baryons and sea antiquark polarizations

Using generalized Sehgal equations for magnetic moments of baryon octet and taking into account $\Sigma^{0}-\Lambda$ mixing and two particle corrections to independent quark contributions we obtain very good fit using experimental values for errors of such moments. We present sum rules for quark magnetic moments ratios and for integrated spin dendities ratios. Due to the SU(3) structure of our equations the results for magnetic moments of quarks and their densities depend on two additional parameters. Using information from deep inelastic scattering and baryon $\beta$-decays we discuss the dependence of antiquark polarizations on introduced parameters. For some plausible values of these parameters we show that these polarizations are small if we neglect angular momenta of quarks. Our very good fit to magnetic moments of baryon octet can still be improved by using specific model for angular momentum of quarks.Comment: Latex, 19 pages 5 eps figures, 2 references added, changes in text to apear in Phys. Rev.

Spectral properties of molecular oligomers. A non-Markovian quantum state diffusion approach

Absorption spectra of small molecular aggregates (oligomers) are considered. The dipole-dipole interaction between the monomers leads to shifts of the oligomer spectra with respect to the monomer absorption. The line-shapes of monomer as well as oligomer absorption depend strongly on the coupling to vibrational modes. Using a recently developed approach [Roden et. al, PRL 103, 058301] we investigate the length dependence of spectra of one-dimensional aggregates for various values of the interaction strength between the monomers. It is demonstrated, that the present approach is well suited to describe the occurrence of the J- and H-bands

Electronic spectra of linear HC5_5H and cumulene carbene H2_2C5_5

The $1 ^3\Sigma_u^- \leftarrow X^3\Sigma_g^-$ transition of linear HC$_5$H (A) has been observed in a neon matrix and gas phase. The assignment is based on mass-selective experiments, extrapolation of previous results of the longer HC$_{2n+1}$H homologues, and density functional and multi-state CASPT2 theoretical methods. Another band system starting at 303 nm in neon is assigned as the $1 ^1 A_1 \leftarrow X ^1 A_1$ transition of the cumulene carbene pentatetraenylidene H$_2$C$_5$ (B).Comment: 7 pages, 4 figures, 5 table

Fully electrically read-write device out of a ferromagnetic semiconductor

We report the realization of a read-write device out of the ferromagnetic semiconductor (Ga,Mn)As as the first step to fundamentally new information processing paradigm. Writing the magnetic state is achieved by current-induced switching and read-out of the state is done by the means of the tunneling anisotropic magneto resistance (TAMR) effect. This one bit demonstrator device can be used to design a electrically programmable memory and logic device.Comment: 4 pages, 4 figure