Spin asymmetries for electron-thallium scattering calculated with the relativistic convergentclose-coupling method

Spin asymmetries for elastic and inelastic scattering of electrons from thallium are presented. Thalliumis a heavy target (Z 81) and the spin asymmetries can be caused by relativistic effects (spin-orbit interactions) in addition to exchange effects

Nonperturbative electron-ion scattering theory incorporating the Møller interaction

We present the first calculations that investigate the effects of both the Møller interaction and close-coupling in the calculation of electron-impact excitation cross sections. Electron scattering from U 91+ is used as a test case. The RCCC method is nonperturbative and we emphasise the restrictions and subsequent limitations associated with employing the Møller interaction in the RCCC method

Comparison of experiment and theory for superelastic electron-collision studies from laser-aligned magnesium

A combined experimental and theoretical study of superelastic electron collisions from laser-aligned magnesium atoms for a range of collision energies from 35 to 55 eV is presented. 24Mg atoms were excited from the 3 1S0 ground state to the 3 1P1 excited state using continuous-wave linearly polarized laser radiation at ∼285 nm. Electrons of well-defined energy Einc then deexcited the targets, and the superelastically scattered electrons emerging from the collision were detected as a function of scattering angle and laser polarization. Results for alignment of the target by the electron beam are presented for a range of scattering angles, for outgoing energies from Eout=35 to 55 eV. The agreement between the measurements and the results of the convergent close-coupling theory are encouraging, but some discrepancies remain

Profiles of resilient psychosocial function during three isolated ski expeditions in the High Arctic

To successfully complete a Polar expedition individuals and teams must respond resiliently to the environmental, psychological, and social demands they face. In this study we examined profiles of resilient function in seven people from three expeditions in the High Arctic. Using a structured daily diary, participants reported on experiences of physical health (morning and evening), affect, team cohesion, performance, and potential explanatory factors including sleep, demand appraisals, events, and coping strategies. Notable intra- and inter-individual variability was observed in daily reports and all profiles could be interpreted as representing resilient function. A number of significant relationships were found between markers of resilient physical and psychosocial function and potential explanatory variables. For example, there was much more daily variability in an individual's reporting of positive affect than prior research might imply, and what prior research designs could capture. Further, while negative affect tended to remain low and stable, our findings reveal that even minor and infrequent increases in negative emotions were significantly associated with other variables in the network. Finally, across the expedition period individual coping resources consistently exceeded demands, suggesting that individuals viewed the expedition as a challenge and not a threat. More broadly, these findings inform efforts to monitor, and maintain resilience when operating in Polar and other extreme settings

The neodymium isotope fingerprint of Adélie coast bottom water

Adélie Land Bottom Water (ALBW), a variety of Antarctic Bottom Water formed off the Adélie Land coast of East Antarctica, ventilates the abyssal layers of the Australian sector of the Southern Ocean as well as the eastern Indian and Pacific Oceans. We present the first dissolved neodymium (Nd) isotope and concentration measurements for ALBW. The summertime signature of ALBW is characterized by εNd = −8.9, distinct from Ross Sea Bottom Water, and similar to Weddell Sea Bottom Water. Adélie Land Shelf Water, the precursor water mass for wintertime ALBW, features the least radiogenic Nd fingerprint observed around Antarctica to date (εNd = −9.9). Local geology around Antarctica is important in setting the chemical signature of individual varieties of Antarctic Bottom Water, evident from the shelf water signature, which should be considered in the absence of direct wintertime observations

Perturbations of Gauss-Bonnet Black Strings in Codimension-2 Braneworlds

We derive the Lichnerowicz equation in the presence of the Gauss-Bonnet term. Using the modified Lichnerowicz equation we study the metric perturbations of Gauss-Bonnet black strings in Codimension-2 Braneworlds.Comment: 26 pages, no figures, clarifying comments and one reference added, to be published in JHE

Bulk Axions, Brane Back-reaction and Fluxes

Extra-dimensional models can involve bulk pseudo-Goldstone bosons (pGBs) whose shift symmetry is explicitly broken only by physics localized on branes. Reliable calculation of their low-energy potential is often difficult because it requires details of the stabilization of the extra dimensions. In rugby ball solutions, for which two compact extra dimensions are stabilized in the presence of only positive-tension brane sources, the effects of brane back-reaction can be computed explicitly. This allows the calculation of the shape of the low-energy pGB potential and response of the extra dimensional geometry as a function of the perturbing brane properties. If the pGB-dependence is a small part of the total brane tension a very general analysis is possible, permitting an exploration of how the system responds to frustration when the two branes disagree on what the proper scalar vacuum should be. We show how the low-energy potential is given by the sum of brane tensions (in agreement with common lore) when only the brane tensions couple to the pGB. We also show how a direct brane coupling to the flux stabilizing the extra dimensions corrects this result in a way that does not simply amount to the contribution of the flux to the brane tensions. We calculate the mass of the would-be zero mode, and briefly describe several potential applications, including a brane realization of `natural inflation,' and a dynamical mechanism for suppressing the couplings of the pGB to matter localized on the branes. Since the scalar can be light enough to be relevant to precision tests of gravity (in a technically natural way) this mechanism can be relevant to evading phenomenological bounds.Comment: 36 pages, JHEP styl