Relativistic descriptions of final-state interactions in neutral-current neutrino-nucleus scattering at MiniBooNE kinematics

The analysis of the recent neutral-current neutrino-nucleus scattering cross sections measured by the MiniBooNE Collaboration requires relativistic theoretical descriptions also accounting for the role of final state interactions. In this work we evaluate differential cross sections with the relativistic distorted-wave impulse-approximation and with the relativistic Green's function model to investigate the sensitivity to final state interactions. The role of the strange-quark content of the nucleon form factors is also discussed.Comment: 8 pages, 5 figure

Models for quasielastic electron and neutrino-nucleus scattering

Models developed for the exclusive and inclusive quasielastic (QE) electron-nucleus scattering have been extended to QE neutrino-nucleus scattering. Different descriptions of final-state interactions (FSI) are compared. For the inclusive electron scattering the relativistic Green's function model (RGF) is compared with a model based on the use of relativistic purely real mean field (RMF) potentials in the final state. Both approaches lead to a redistribution of the strength but conserving the total flux. Results for electron and neutrino scattering are presented and discussed in different conditions and kinematics. The results of the RGF and RMF models are compared with the double-differential charged-current QE neutrino cross sections recently measured by the MiniBooNE collaboration using a carbon target.Comment: 12 pages, 7 figures, contribution to the XIII Conference on Problems in Theoretical Nulcear Physics in Italy, Cortona 6-8 April 201

Electron-induced proton knockout from neutron rich nuclei

We study the evolution of the \eep cross section on nuclei with increasing asymmetry between the number of neutrons and protons. The calculations are done within the framework of the nonrelativistic and relativistic distorted-wave impulse approximation. In the nonrelativistic model phenomenological Woods-Saxon and Hartree-Fock wave functions are used for the proton bound-state wave functions, in the relativistic model the wave functions are solutions of Dirac-Hartree equations. The models are first tested against experimental data on $^{40}$Ca and $^{48}$Ca nuclei, and then they are applied to a set of spherical calcium isotopes.Comment: 5 pages, 2 figures. contribution to the XIX International School on Nuclear Physics, Neutron Physics and Applications, Varna (Bulgaria) September 19-25, 201

Ad- and desorption of Rb atoms on a gold nanofilm measured by surface plasmon polaritons

Hybrid quantum systems made of cold atoms near nanostructured surfaces are expected to open up new opportunities for the construction of quantum sensors and for quantum information. For the design of such tailored quantum systems the interaction of alkali atoms with dielectric and metallic surfaces is crucial and required to be understood in detail. Here, we present real-time measurements of the adsorption and desorption of Rubidium atoms on gold nanofilms. Surface plasmon polaritons (SPP) are excited at the gold surface and detected in a phase sensitive way. From the temporal change of the SPP phase the Rubidium coverage of the gold film is deduced with a sensitivity of better than 0.3 % of a monolayer. By comparing the experimental data with a Langmuir type adsorption model we obtain the thermal desorption rate and the sticking probability. In addition, also laser-induced desorption is observed and quantified.Comment: 9 pages, 6 figure

Power-laws in recurrence networks from dynamical systems

Recurrence networks are a novel tool of nonlinear time series analysis allowing the characterisation of higher-order geometric properties of complex dynamical systems based on recurrences in phase space, which are a fundamental concept in classical mechanics. In this Letter, we demonstrate that recurrence networks obtained from various deterministic model systems as well as experimental data naturally display power-law degree distributions with scaling exponents $\gamma$ that can be derived exclusively from the systems' invariant densities. For one-dimensional maps, we show analytically that $\gamma$ is not related to the fractal dimension. For continuous systems, we find two distinct types of behaviour: power-laws with an exponent $\gamma$ depending on a suitable notion of local dimension, and such with fixed $\gamma=1$.Comment: 6 pages, 7 figure

Author Correction: Identification of minimal parameters for optimal suppression of chaos in dissipative driven systems

Correction to: Scientific Reports https://doi.org/10.1038/s41598-017-17969-9, published online 21 December 201

A possible tremorgenic mycotoxicosis by Roquefortine C in a bovine herd

A total of 15 beef cows and calves were referred for history of neurological signs. The animals (12/15 Chianina breed, 3/15 Limousine) were grazing in 300 ha area, fed with grass and hay. Inspection of the hay reveled macroscopic alterations, consisting of diffuse and heavy mold contamination of many hay bales. Due to the not cooperative attitude, the animals were only visually examined in the field; the neurological signs observed were ataxia, intentional head tremors and muscle twitching. Only 3 calves with severe neurological signs were housed in a medication area and underwent a complete clinical exam. All 3 calves showed intentional head tremors and muscle twitching; 1/3 presented severe ataxia and stiffness gait, while 2/3 calves were recumbent and unable to rise. The most important clinical data were: hyperthermia, tachypnea, tachycardia and long capillary refill time. The neurological examination showed deficits of V and VII cranial nerves. Calves could swallow, but they were unable to grab the food. Based on history and clinical examination the following differential diagnoses were considered: tremorgenic mycotoxicosis, nervous ketosis, nervous BVD form, BHV1-5, Listeriosis and WMD. Blood samples were collected for CBC count and biochemistry panel (TP, urea, creatinine, total and direct bilirubin, GGT, AST, CPK, Mg, Se and vit E), urinalysis was performed for ketone bodies. Calves were also tested for infectious diseases (Listeriosis, BVD, BHV 1-5). Multiple samples of altered hay were analyzed for mycotoxins and hay balls were removed in all animals’ stock. The grazing animals recovered spontaneously within 1 week along with 2/3 hospitalized calves, while 1/3 calf was euthanized due to poor general conditions. CBC, biochemistry panel, vit E and oligo-minerals resulted within normal ranges and no positivity for infectious agents were detected. Food analysis showed high concentrations of roquefortine C (RC): 345 μg/kg DM. Presence of RC in livestock food is highly reported, in particular in visibly moldy areas (1). RC intoxication causes anorexia, paralysis and several reports attribute it neurotoxic properties (2). In mice experimental intoxications induced muscle contractions, ataxia, prostration and intermittent seizures. RC intoxication, resembling penitrem A (PA) intoxication, has been reported in dogs. Moreover, RC is considered a sensitive biomarker for PA exposure. PA is a tremorgenic fungal toxin which intoxication causes ataxia, tachypnea, and sustained tremors. The pathophysiological mechanism by which mycotoxins affect the CNS is unknown but the biochemical lesions are reversible. Diagnosis is based on the clinical signs, demonstration of the mycotoxins in the feed and identification of the fungal elements in blood and feces. Affected animals recover completely when they are removed from infected pastures. Based on neurological signs, recovery after altered food removing and results of food analysis, the diagnosis of tremorgenic intoxication was hypothesized. Limits of this report are: lack of PA dosage in the food and lack of RC and PA evaluation in blood and feces of affected animals