Microscopic Origin of Quantum Chaos in Rotational Damping

The rotational spectrum of $^{168}$Yb is calculated diagonalizing different effective interactions within the basis of unperturbed rotational bands provided by the cranked shell model. A transition between order and chaos taking place in the energy region between 1 and 2 MeV above the yrast line is observed, associated with the onset of rotational damping. It can be related to the higher multipole components of the force acting among the unperturbed rotational bands.Comment: 7 pages, plain TEX, YITP/K-99

Rotational Damping and Compound Formation in Warm Rotating Nuclei

The rotational damping width \Gamma_{rot} and the compound damping width \Gamma_{comp} are two fundamental quantities that characterize rapidly rotating compound nuclei having finite thermal excitation energy. A two-component structure in the strength function of consecutive E2 transitions reflects the two widths, and it causes characteristic features in the double and triple gamma-ray spectra. We discuss a new method to extract experimentally values of \Gamma_{rot} and \Gamma_{comp}. The first preliminary result of this method is presented.Comment: PDF, 8 pages, invited talk at the Conference on Frontiers of Nuclear Structure (FNS2002), August 2002, Berkele

Intergenerational change and familial aggregation of body mass index

The relationship between parental BMI and that of their adult offspring, when increased adiposity can become a clinical issue, is unknown. We investigated the intergenerational change in body mass index (BMI) distribution, and examined the sex-specific relationship between parental and adult offspring BMI. Intergenerational change in the distribution of adjusted BMI in 1,443 complete families (both parents and at least one offspring) with 2,286 offspring (1,263 daughters and 1,023 sons) from the west of Scotland, UK, was investigated using quantile regression. Familial correlations were estimated from linear mixed effects regression models. The distribution of BMI showed little intergenerational change in the normal range (\25 kg/m2), decreasing overweightness (25– \30 kg/m2) and increasing obesity (C30 kg/m2). Median BMI was static across generations in males and decreased in females by 0.4 (95% CI: 0.0, 0.7) kg/m2; the 95th percentileincreased by 2.2 (1.1, 3.2) kg/m2 in males and 2.7 (1.4, 3.9) kg/m2 in females. Mothers’ BMI was more strongly associated with daughters’ BMI than was fathers’ (correlation coefficient (95% CI): mothers 0.31 (0.27, 0.36), fathers 0.19 (0.14, 0.25); P = 0.001). Mothers’ and fathers’ BMI were equally correlated with sons’ BMI (correlation coefficient: mothers 0.28 (0.22, 0.33), fathers 0.27 (0.22, 0.33). The increase in BMI between generations was concentrated at the upper end of the distribution. This, alongside the strong parent-offspring correlation, suggests that the increase in BMI is disproportionally greater among offspring of heavier parents. Familial influences on BMI among middle-aged women appear significantly stronger from mothers than father

Strong Deformation Effects in Hot Rotating 46Ti

Exotic-deformation effects in 46Ti nucleus were investigated by analysing the high-energy gamma-ray and the alpha-particle energy spectra. One of the experiments was performed using the charged-particle multi-detector array ICARE together with a large volume (4"x4") BGO detector. The study focused on simultaneous measurement of light charged particles and gamma-rays in coincidence with the evaporation residues. The experimental data show a signature of very large deformations of the compound nucleus in the Jacobi transition region at the highest spins. These results are compared to data from previous experiments performed with the HECTOR array coupled to the EUROBALL array, where it was found that the GDR strength function is highly fragmented, strongly indicating a presence of nuclei with very large deformation.Comment: 10 pages, 6 figures, Proceedings of the Zakopane Conference on Nuclear Physics, to be published in Acta Phys. Pol. B (2007

Biology and genetics of human longevity

Human longevity is a multifactorial trait, which includes a network of genes combined with strong environmental factors. Biological and clinical characteristics of human beings are the result of the interaction between genes and the environment. Until about 1950 centenarians were quite rare in low-mortality countries. Since then the number has more than doubled every 10 years and even the number of 105+ year old people is now increasing. This proliferation of centenarians is mainly a result of the decrease in oldest-old mortality and probably due to changes of lifestyle and health care. Although studies of Danish twin pairs seem to indicate that genetic influence on human lifespan is only moderate, several gene loci contribute to longevity. Data are evident from the Italian Centenarian Study for apoproteinB, tyrosine hydroxylase and mitochondrial DNA loci among others studied (superoxide dismutases, ie. SOD1 and SOD2, poly(ADP-ribose)polymerase and thyroid peroxidase). The data from the Danish Centenarian Study confirm the findings from the studies of French and Finnish centenarians on apolipoprotein E genotype with a higher frequency of epsilon-2 and lower frequency of epsilon-However, the apoE genotype seems not to be a key determinant of exceptional longevity: in 105+ year olds the epsilon-4 allele was found in 4 out of 19 persons. Italian centanarians have a paradoxically marked hypercoagulability as demonstrated also by genetic markers. Also the von Willebrand factor was increased independently of the blood group. Studies on such atherosclerosis risk factors as lipoprotein(a) and homocysteine revealed that these two parameters may be high in Italian centenarians, but their genetic control possibly attenuates with age, and environmental factors may play a major role in the oldest-old persons. Also interaction among genes is possible. All these studies suggest that longevity is a phoenornenon depending on multiple genetic and environmental factors. Further studies are needed for a better understanding of the complex interactions which allow people to reach a very old age

Design, Fabrication, and Experimental Demonstration of Junction Surface Ion Traps

We present the design, fabrication, and experimental implementation of surface ion traps with Y-shaped junctions. The traps are designed to minimize the pseudopotential variations in the junction region at the symmetric intersection of three linear segments. We experimentally demonstrate robust linear and junction shuttling with greater than one million round-trip shuttles without ion loss. By minimizing the direct line of sight between trapped ions and dielectric surfaces, negligible day-to-day and trap-to-trap variations are observed. In addition to high-fidelity single-ion shuttling, multiple-ion chains survive splitting, ion-position swapping, and recombining routines. The development of two-dimensional trapping structures is an important milestone for ion-trap quantum computing and quantum simulations.Comment: 9 pages, 6 figure

Demonstration of integrated microscale optics in surface-electrode ion traps

In ion trap quantum information processing, efficient fluorescence collection is critical for fast, high-fidelity qubit detection and ion-photon entanglement. The expected size of future many-ion processors require scalable light collection systems. We report on the development and testing of a microfabricated surface-electrode ion trap with an integrated high numerical aperture (NA) micromirror for fluorescence collection. When coupled to a low NA lens, the optical system is inherently scalable to large arrays of mirrors in a single device. We demonstrate stable trapping and transport of 40Ca+ ions over a 0.63 NA micromirror and observe a factor of 1.9 enhancement in photon collection compared to the planar region of the trap.Comment: 15 pages, 8 figure

Transport of charged particles by adjusting rf voltage amplitudes

We propose a planar architecture for scalable quantum information processing (QIP) that includes X-junctions through which particles can move without micromotion. This is achieved by adjusting radio frequency (rf) amplitudes to move an rf null along the legs of the junction. We provide a proof-of-principle by transporting dust particles in three dimensions via adjustable rf potentials in a 3D trap. For the proposed planar architecture, we use regularization techniques to obtain amplitude settings that guarantee smooth transport through the X-junction.Comment: 16 pages, 10 figure

Radium ion: A possible candidate for measuring atomic parity violation

Single trapped and laser cooled Radium ion as a possible candidate for measuring the parity violation induced frequency shift has been discussed here. Even though the technique to be used is similar to that proposed by Fortson [1], Radium has its own advantages and disadvantages. The most attractive part of Radium ion as compared to that of Barium ion is its mass which comes along with added complexity of instability as well as other issues which are discussed hereComment: Conference proceedin

Fabrication of a planar micro Penning trap and numerical investigations of versatile ion positioning protocols

We describe a versatile planar Penning trap structure, which allows to dynamically modify the trapping conguration almost arbitrarily. The trap consists of 37 hexagonal electrodes, each with a circumcirle-diameter of 300 m, fabricated in a gold-on-sapphire lithographic technique. Every hexagon can be addressed individually, thus shaping the electric potential. The fabrication of such a device with clean room methods is demonstrated. We illustrate the variability of the device by a detailed numerical simulation of a lateral and a vertical transport and we simulate trapping in racetrack and articial crystal congurations. The trap may be used for ions or electrons, as a versatile container for quantum optics and quantum information experiments.Comment: 10 pages, 7 figures, pdflatex, to be published in New Journal of Physics (NJP) various changes according to the wishes of the NJP referees. Text added and moved around, title changed, abstract changed, references added rev3: one reference had a typo (ref 15), fixed (phys rev a 72, not 71