Strong field effects on physics processes at the Interaction Point of future linear colliders

Future lepton colliders will be precision machines whose physics program includes close study of the Higgs sector and searches for new physics via polarised beams. The luminosity requirements of such machines entail very intense lepton bunches at the interaction point with associated strong electromagnetic fields. These strong fields not only lead to obvious phenomena such as beamstrahlung, but also potentially affect every particle physics process via virtual exchange with the bunch fields. For precision studies, strong field effects have to be understood to the sub-percent level. Strong external field effects can be taken into account exactly via the Furry Picture or, in certain limits, via the Quasi-classical Operator method . Significant theoretical development is in progress and here we outline the current state of play.Comment: 6 pages, ICHEP 2012 Proceeding

Copper and Barium Abundances in the Ursa Major Moving Group

We present Cu and Ba abundances for 7 G-K dwarf stars, members of the solar-metallicity, 0.3 Gyr old Ursa Major Moving Group. All analyzed member stars show [Ba/Fe] excesses of +0.3-plus, associated with [Cu/Fe] deficiencies of up to -0.23 dex. The present results suggest that there is an anti-correlation between the abundances of Cu and the heavy elements produced by the main component of the neutron capture s-process. Other possible anomalies are Na and C deficiencies with respect to normal solar-metallicity stars. The new data do not confirm the recent claim that the group member HR6094 is a Ba dwarf star.Comment: 8 pages, 6 figures, accepted to MNRA

On the comparison of results regarding the post-Newtonian approximate treatment of the dynamics of extended spinning compact binaries

A brief review is given of all the Hamiltonians and effective potentials calculated hitherto covering the post-Newtonian (pN) dynamics of a two body system. A method is presented to compare (conservative) reduced Hamiltonians with nonreduced potentials directly at least up to the next-to-leading-pN order.Comment: Conference proceedings for the 7th International Conference on Gravitation and Cosmology (ICGC2011), 4 page

A lattice of double wells for manipulating pairs of cold atoms

We describe the design and implementation of a 2D optical lattice of double wells suitable for isolating and manipulating an array of individual pairs of atoms in an optical lattice. Atoms in the square lattice can be placed in a double well with any of their four nearest neighbors. The properties of the double well (the barrier height and relative energy offset of the paired sites) can be dynamically controlled. The topology of the lattice is phase stable against phase noise imparted by vibrational noise on mirrors. We demonstrate the dynamic control of the lattice by showing the coherent splitting of atoms from single wells into double wells and observing the resulting double-slit atom diffraction pattern. This lattice can be used to test controlled neutral atom motion among lattice sites and should allow for testing controlled two-qubit gates.Comment: 9 pages, 11 figures Accepted for publication in Physical Review

Seismic Analysis of Traditional Stone Rural Buildings: Case study of a one-storey building

Specific features of traditional rural buildings can influence the assessment of their seismic behaviour. When a change in intended use of traditional rural buildings is necessary, restoration work must comply with specific seismic norms and should preserve their original features. In this paper, a model for the seismic safety verification of masonry walls for inplane actions was applied to investigate the structural behaviour of one-storey stone-masonry traditional rural buildings, in relation to standards application and possible retrofitting interventions. The results showed that pier-panel collapse mechanisms and the simulation method of masonry spandrel behaviour are of importance and affect the need to provide for strengthening interventions

Kernel density estimation analyses based on a low power-global positioning system for monitoring environmental issues of grazing cattle

The use of wearable sensors that record animal activity in intensive livestock systems has become more and more frequent for both early detection of diseases and improving production quality. Their application may also be significant in extensive livestock systems, with infrequent farmer-to-animal contact. The pre-sent study aimed to prove the feasibility of a novel automatic sys- tem for locating and tracking cows in extensive livestock systems based on space-time data provided by a low-power global positioning system (LP-GPS). The information was used to study the pasture exploitation by the herd for modelling the environmental impacts of extensive livestock systems through geographical information systems (GIS). A customised device, placed within a rectangular PVC case compatible with the collar usually worn by animals, was equipped with an LP-GPS omnidirectional system, an integrated SigFox communication system, and a power supply. The experimental trial was conducted in an existing semi-natural pasture characterised by good pasture allowance and cultivated grazing areas. Ten cows were embedded with LP-GPS collars, and the data, i.e., geographical coordinates and the time intervals related to each cow detection, were recorded every 20 minutes. Data were collected through a specifically developed AppWeb to be further imported and elaborated by using a GIS software tool. In the GIS environment, the daily distances travelled by each cow were linked with heatmaps obtained by applying Kernel density estimation models from the points obtained from the LP-GPS col-lars. The study results made it possible to obtain information on some relevant aspects of livestock’s environmental issues. In detail, it was possible to acquire information on herd behaviour related to the use of the pasture, e.g., the area of the pasture most frequently used during the day, individual use of the pasture, and possible animal interactions. These results represent the first step towards further insights and research activities because monitoring of animal locations could reduce several environmental issues such as soil degradation and greenhouse emissions. r

On the exponential Diophantine equation p⋅3x+py=z2{\displaystyle p\cdot 3^{x}+p^{y}=z^2} with pp a prime number

In this paper we find non-negative integer solutions for exponential Diophantine equations of the type $p \cdot 3^x+ p^y=z^2,$ where $p$ is a prime number. We prove that such equation has a unique solution $\displaystyle{(x,y,z)=\left(\log_3(p-2), 0, p-1\right)}$ if $2 \neq p \equiv 2 \pmod 3$ and $(x,y,z)=(0,1,2)$ if $p=2$. We also display the infinite solution set of that equation in the case $p=3$. Finally, a brief discussion of the case $p \equiv 1 \pmod 3$ is made, where we display an equation that does not have a non-negative integer solution and leave some open questions. The proofs are based on the use of the properties of the modular arithmetic

Magic wavelengths for the 5s−18s5s-18s transition in rubidium

Magic wavelengths, for which there is no differential ac Stark shift for the ground and excited state of the atom, allow trapping of excited Rydberg atoms without broadening the optical transition. This is an important tool for implementing quantum gates and other quantum information protocols with Rydberg atoms, and reliable theoretical methods to find such magic wavelengths are thus extremely useful. We use a high-precision all-order method to calculate magic wavelengths for the $5s-18s$ transition of rubidium, and compare the calculation to experiment by measuring the light shift for atoms held in an optical dipole trap at a range of wavelengths near a calculated magic value