The bound-electron g factor is a stringent tool for tests of the standard model and the search for new physics. The comparison between an experiment on the g factor of lithiumlike silicon and the two ...recent theoretical values revealed the discrepancies of 1.7σ Glazov et al. Phys. Rev. Lett. 123, 173001 (2019)PRLTAO0031-900710.1103/PhysRevLett.123.173001 and 5.2σ Yerokhin et al. Phys. Rev. A 102, 022815 (2020)PLRAAN2469-992610.1103/PhysRevA.102.022815. To identify the reason for this disagreement, we accomplish large-scale high-precision computation of the interelectronic-interaction and many-electron QED corrections. The calculations are performed within the extended Furry picture of QED, and the dependence of the final values on the choice of the binding potential is carefully analyzed. As a result, we significantly improve the agreement between the theory and experiment for the g factor of lithiumlike silicon. We also report the most accurate theoretical prediction to date for lithiumlike calcium, which perfectly agrees with the experimental value.
The joint recurrence analysis is used to reveal differences in the phase synchronization between intermittent photic stimulation and brain responses of patients with cardiac fibrillation of ...paroxysmal and persistent types. As a measure of phase synchronization between two signals, we consider the mutual correlation factor between recurrence probabilities of corresponding phase trajectories. The value of this coefficient increases upon an increase in the cardiac fibrillation time and in the extent of decline of cognitive functions for brain responses to theta-range frequencies.
The strong mixing of close levels with two valence electrons in Be-like xenon greatly complicates ab initio QED calculations beyond the first-order approximation. Because of a strong interplay ...between the electron-electron correlation and QED effects, the standard single-level perturbative QED approach may fail, even if it takes into account the second-order screened QED diagrams. In the present Letter, the corresponding obstacles are overcome by working out the QED perturbation theory for quasidegenerate states. The contributions of all the Feynman diagrams up to the second order are taken into account. The many-electron QED effects are rigorously evaluated in the framework of the extended Furry picture to all orders in the nuclear-strength parameter αZ. The higher-order electron-correlation effects are considered within the Breit approximation. The nuclear recoil effect is accounted for as well. The developed approach is applied to high-precision QED calculations of the ground and singly excited energy levels in Be-like xenon. The most accurate theoretical predictions for the binding and excitation energies are obtained. These results deviate from the most precise experimental value by 3σ but perfectly agree with a more recent measurement.
MicroRNA (miRNA) and other types of small regulatory RNAs play a crucial role in the regulation of gene expression in eukaryotes. Several distinct classes of small regulatory RNAs have been ...discovered in recent years. To extend the repertoire of small regulatory RNAs characterized in chickens we used a deep sequencing approach developed by Solexa (now Illumina Inc.). We sequenced three small RNA libraries prepared from different developmental stages of the chicken embryo (days five, seven, and nine) to produce over 9.5 million short sequence reads. We developed a bioinformatics pipeline to distinguish authentic mature miRNA sequences from other classes of small RNAs and short RNA fragments represented in the sequencing data. Using this approach we detected almost all of the previously known chicken miRNAs and their respective miRNA* sequences. In addition we discovered 449 new chicken miRNAs including 88 miRNA candidates. Of these, 430 miRNAs appear to be specific to the avian lineage. Another six new miRNAs had evidence of evolutionary conservation in at least one vertebrate species outside of the bird lineage. The remaining 13 putative miRNAs appear to represent chicken orthologs of known vertebrate miRNAs. We discovered 39 additional putative miRNA candidates originating from miRNA generating intronic sequences known as mirtrons.
HERAFitter Alekhin, S.; Behnke, O.; Belov, P. ...
The European physical journal. C, Particles and fields,
07/2015, Letnik:
75, Številka:
7
Journal Article
Recenzirano
Odprti dostop
HERAFitter is an open-source package that provides a framework for the determination of the parton distribution functions (PDFs) of the proton and for many different kinds of analyses in Quantum ...Chromodynamics (QCD). It encodes results from a wide range of experimental measurements in lepton–proton deep inelastic scattering and proton–proton (proton–antiproton) collisions at hadron colliders. These are complemented with a variety of theoretical options for calculating PDF-dependent cross section predictions corresponding to the measurements. The framework covers a large number of the existing methods and schemes used for PDF determination. The data and theoretical predictions are brought together through numerous methodological options for carrying out PDF fits and plotting tools to help to visualise the results. While primarily based on the approach of collinear factorisation, HERAFitter also provides facilities for fits of dipole models and transverse-momentum dependent PDFs. The package can be used to study the impact of new precise measurements from hadron colliders. This paper describes the general structure of HERAFitter and its wide choice of options.
A change in temperature during adiabatic elastic deformation of solids (thermoelastic effect) is determined in terms of the thermodynamic approach taking into account the existence of internal ...defects in them. A contribution of the defect structure of a material to the Kelvin formula as determined as there are mechanical stresses in a material. It is shown that the changes in the thermal expansion coefficient of a material due to a dependence of the elastic modulus and the defect concentration on temperature can have opposite directionalities.
The task is to determine the indices of phase synchronization between biological data extracted from neuronal activity and fluctuations in blood pressure and respiration, based on the calculation of ...instantaneous frequencies and phases using the synchrosqueezed wavelet analysis. Differences in synchronization indices between the analyzed data in two groups of rats (the control group and the group with experimentally induced colitis) were revealed. Pain exposure was found to be associated with frequency adjustment of the variability of the neuronal activity or the blood pressure, followed by the onset of phase synchronization.
Differences in phase synchronization between intermittent photic stimulation and electrical activity of the brain recorded as electroencephalographic (EEG) patterns were studied in two groups of ...patients with chronically elevated arterial pressure with and without cognitive impairment. It was found that the parameters of phase synchronization calculated using synchrosqueezed wavelet transform of the light stimulus and the EEG pattern can be used as neurophysiological markers of moderate cognitive impairment.
A theoretical model for the formation of ultrasonic signals in metallic microcrystalline rods taking into account the metastable behavior of their defective states is proposed. The influence of ...metastable states of the defective structure of samples on the features of changes in their resonant frequencies in ultrasonic experiments of fast dynamics is analyzed. The decrease in Young’s modulus in such processes is explained. The correspondence between theoretical and experimental data is demonstrated for the example of resonant acoustic vibrations of rods made of aluminum alloy D16.
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