Subdominant Channels Research Articles

Развитие на комуникативните умения при деца с алалия в условията на мултисензорно обучение

Speech is a main function, which has a defining meaning for the whole psychological development of the child as a personality. It is subordinate to the objective laws of language and runs through certain stages. At the same time without special and purposeful special-pedagogical intervention speech activity of children at preschool age with alalia isn’t realized spontaneously, preverbal forms of communication aren’t formed, either. One of the conditions is multisensory approach, which suggests using the whole structure of polimodal perception of the child – with the participation of the subdominant channels. In the article the main point of sensory integration is considered. The main focus is on the development of aural impressions, visual perception, tactile-kinesthetic emotions and sense perception, their role in the speech development of children with alalia. Multisensory approach contributes to the development and improvement of the communicative abilities of children with alalia.

Theoretical Investigation of the Chiral Transition of α‐Alanine Cu2+ Complex in Water Solution

AbstractThe chiral transition of S‐α‐alanine Cu2+ complex (S−A) in water solution was investigated by density functional theory combined with SMD solvation model. In principle, the chiral transition of S−A could be realized via the following four pathways: carbonyl oxygen as the bridge, carbonyl oxygen and amino nitrogen as the bridge, amino nitrogen as the bridge and Cu as the bridge. The potential energy surface calculation shows that under the effect of implicit solvent, the reaction channel with Cu as the bridge is the most dominant, and the energy barrier of the rate‐determining steps is 103.3 kJ mol−1. The subdominant channel of hydrogen migration is the bridge channel of amino nitrogen, and the energy barrier of the rate‐determining steps is 183.5 kJ mol−1. The remaining two channels are inferior channels. Under the explicit solvent effect, the channel with amino‐nitrogen as the bridge is the most advantageous, and the energy barrier of the rate‐determining steps is reduced to 138.0 kJ mol−1. The subdominant channel for hydrogen migration is Cu, and the energy barrier of the rate‐determining steps increases to 145.3 kJ mol−1. The remaining two channels are inferior channels. The results show that S−A complex can better maintain its chiral characteristics in water solution, and the divalent copper salt of α‐alanine is safe to supplement Cu2+ and alanine in living bodies.

Complete predictions for high-energy neutrino propagation in matter

We present predictions for the interactions of energetic neutrinos with matter as they propagate through Earth towards large-volume detectors. Our results are based on state-of-the-art calculations of the high-energy neutrino-matter interaction cross-sections, which we have implemented in the HEDIS module of GENIE. In addition to the dominant interaction process, deep inelastic scattering off quarks and gluons, we include the relevant subdominant channels: (in)elastic scattering off the photon field of nucleons, coherent scattering off the photon field of nuclei, as well as the scattering on atomic electrons via the Glashow resonance. Our predictions for the neutrino attenuation rates are provided by a new software package, NuPropEarth. We quantify the dependence of our results on the cross-section model, including nuclear corrections, the incidence angle, and the spectral index, and compare them with other publicly available tools.

Doubly charged Higgs boson production at hadron colliders

We present a systematic comparison of doubly charged Higgs boson production mechanisms at hadron colliders in the context of the Type II Seesaw model, emphasizing the importance of higher-order corrections and subdominant channels. We consider the Drell-Yan channel at next-to-leading order in QCD, photon fusion at leading order, gluon fusion with resummation of threshold logarithms up to next-to-next-to-next-to-leading logarithmic accuracy, and same-sign weak boson fusion at next-to-leading order in QCD. For Drell-Yan processes, we study the impact of a static jet veto at next-to-leading order matched to the resummation of jet veto scale logarithms at next-to-next-to-leading logarithmic accuracy. For the photon fusion channel, the dependence on modeling photon parton distribution functions is definitively assessed. To model vector boson fusion at next-to-leading order, we include all interfering topologies at $\mathcal{O}(\alpha^4)$ and propose a method for introducing generator-level cuts within the MC@NLO formalism. Our results are obtained using a Monte Carlo tool chain linking the \textsc{FeynRules}, \textsc{NloCT} and \textsc{MadGraph5\_aMC@NLO} programs and have necessitated the development of new, publicly available, Universal FeynRules Output libraries that encode the interactions between the Type II Seesaw scalars and Standard Model particles. Libraries are compatible with both the normal and inverted ordering of Majorana neutrino masses.

LHC signals from cascade decays of warped vector resonances

Recently (arXiv:1608.00526), a new framework for warped higher-dimensional compactifications with “bulk” standard model (SM) was proposed: in addition to the UV (Planck scale) and IR (a couple of TeV) branes, there is an intermediate brane, taken to be around 10TeV. The SM matter and Higgs fields propagate from the UV brane down to this intermediate brane only, while gauge and gravity fields propagate in the entire bulk. Such a configuration renders the lightest gauge Kaluza-Klein (KK) states within LHC reach, simultaneously satisfying flavor and CP constraints. In addition, the usual leading decay modes of the lightest KK gauge bosons into top and Higgs bosons are suppressed. This effect permits erstwhile subdominant channels to become significant. These include flavor-universal decays to SM fermions and Higgs bosons, and a novel channel — decay to a radion and a SM gauge boson, followed by radion decay to a pair of SM gauge bosons. In this work, we first delineate the parameter space where the above mentioned cascade decay of gauge KK particles dominates, and thereby can be the discovery mode at the LHC. We then perform a detailed analysis of the LHC signals from this model, finding that 300/fb suffices for evidence of KK-gluon in tri-jet, jet + di-photon and jet + di-boson channels. However, KK photon in photon + di-jet, and KK-W in leptonic W + di-jet require 3000/fb. The crucial feature of this decay chain is a “double” resonance, i.e. 3-particle and 2-particle invariant mass peaks, corresponding to the KK gauge boson and the radion respectively.

Magnetic Intragap States and Mixed Parity Pairing at the Edge of Spin-Triplet Superconductors

We show that a spontaneous magnetic moment may appear at the edge of a spin-triplet superconductor if the system allows for pairing in a subdominant channel. To unveil the microscopic mechanism behind such an effect, we combine numerical solution of the Bogoliubov-de Gennes equations for a tight-binding model with nearest-neighbor attraction, and the symmetry based Ginzburg-Landau approach. We find that a potential barrier modulating the electronic density near the edge of the system leads to a nonunitary superconducting state close to the boundary where spin-singlet pairing coexists with the dominant triplet superconducting order. We demonstrate that the spin polarization at the edge appears due to the inhomogeneity of the nonunitary state and originates in the lifting of the spin degeneracy of the Andreev bound states.

Raman-Scattering Detection of Nearly Degenerates-Wave andd-Wave Pairing Channels in Iron-BasedBa0.6K0.4Fe2As2andRb0.8Fe1.6Se2Superconductors

We show that electronic Raman scattering affords a window into the essential properties of the pairing potential V(k,k') of iron-based superconductors. In Ba0.6K0.4Fe2As2 we observe band dependent energy gaps along with excitonic Bardasis-Schrieffer modes characterizing, respectively, the dominant and subdominant pairing channel. The d(x(2)-y(2)) symmetry of all excitons allows us to identify the subdominant channel to originate from the interaction between the electron bands. Consequently, the dominant channel driving superconductivity results from the interaction between the electron and hole bands and has the full lattice symmetry. The results in Rb(0.8)Fe(1.6)Se(2) along with earlier ones in Ba(Fe(0.939)Co(0.061))(2)As(2) highlight the influence of the Fermi surface topology on the pairing interactions.

ELECTROWEAK SYMMETRY BREAKING AND THE HIGGS BOSON: CONFRONTING THEORIES AT COLLIDERS

In this review, we discuss methods of parsing direct information from collider experiments regarding the Higgs boson and describe simple ways in which experimental likelihoods can be consistently reconstructed and interfaced with model predictions in pertinent parameter spaces. We review prevalent scenarios for extending the electroweak symmetry breaking sector and emphasize their predictions for nonstandard Higgs phenomenology that could be observed in large hadron collider (LHC) data if naturalness is realized in particular ways. Specifically we identify how measurements of Higgs couplings can be used to imply the existence of new physics at particular scales within various contexts. The most dominant production and decay modes of the Higgs-like state observed in the early data sets have proven to be consistent with predictions of the Higgs boson of the Standard Model, though interesting directions in subdominant channels still exist and will require our careful attention in further experimental tests. Slightly anomalous rates in certain channels at the early LHC have spurred effort in model building and spectra analyses of particular theories, and we discuss these developments in some detail. Finally, we highlight some parameter spaces of interest in order to give examples of how the data surrounding the new state can most effectively be used to constrain specific models of weak scale physics.

Low-temperature magnetic penetration depth in d-wave superconductors: Zero-energy bound state and impurity effects

We report a theoretical study on the deviations of the Meissner penetration depth $\ensuremath{\lambda}(T)$ from its London value in d-wave superconductors at low temperatures. The difference arises from low-energy surface Andreev bound states. The temperature dependent penetration depth is shown to go through a minimum at the temperature ${T}_{m0}\ensuremath{\sim}\sqrt{{\ensuremath{\xi}}_{0}/{\ensuremath{\lambda}}_{0}}{T}_{c}$ if the broadening of the bound states is small. The minimum will straighten out when the broadening reaches ${T}_{m0}.$ The impurity scattering sets up the low-temperature anomalies of the penetration depth and destroys them when the mean free path is not sufficiently large. A phase transition to a state with a spontaneous surface supercurrent is investigated and its critical temperature determined in the absence of a subdominant channel activated at low temperatures near the surface. Nonlinear corrections from Andreev low-energy bound states to the penetration length are obtained and shown, on account of their broadening, to be small in the Meissner state of strong type-II superconductors.

Subdominant pairing channels in unconventional superconductors: Ginzburg-Landau theory

A Ginzburg-Landau theory is developed for unconventional superconductors with the three relevant singlet pairing channels. Various consequences of the sub-dominant channels (i.e., s- and d_{xy}-channels) are examined in detail. (1) In the case of a d_{x^2-y^2}+is-wave superconductor, The structure of a single vortex above and below T_{DS} is four-fold and two-fold symmetric, respectively. (2) In the case of a d_{x^2-y^2}+id_{xy}-wave superconductor, there is also a second order zero-field phase transition from the pure d_{x^2-y^2}-phase to the Time-reversal-symmetry-breaking d_{x^2-y^2}+id_{xy}-wave phase at the temperature T_{DD'}. But the subdominant phase can (not) be induced by vortices above T_{DD'}. Below the time-reversal- symmetry-breaking transition, the sub-dominant phase in the mixed state is nontrivial: it survives at low fields, but may disappear above a field (increasing with decreasing temperature) presumably via a first-order transition. (3)By including the strong coupling effects, a time-reversal-symmetry -breaking coupling term between the d_{x^2-y^2}- and d_{xy}-waves is found to have significant effects on the low temperature behavior of d_{x^2-y^2}+id_{xy} superconductors. In a magnetic field, a d_{x^2-y^2}+id_{xy} state is always established, but the field-dependence of d_{xy}-amplitude above T_{DD'} is different from that below T_{DD'}. Above but not very close to T_{DD'}, the induced minimum gap Delta_0 proportional to B/(T-T_{DD'}).

THERMODYNAMICS OF SUPERCONDUCTING LATTICE FERMIONS

We consider the Cooper-problem on a lattice model including onsite and near-neighbor interactions. Expanding the interaction in basis functions for the irreducible representations of the point group C4v yields a classification of the symmetry of the Cooper-pair wave function, which we calculate in real-space. A change of symmetry upon doping, from s-wave at low filling fractions, to dx2-y2 at higher filling fractions, is found. Fermi-surface details are thus important for the symmetry of the superconducting wave function. Symmetry forbids mixing of s-wave and d-wave symmetry in the Cooper-pair wave function on a square lattice, unless accidental degeneracies occur. This conclusion also holds for the selfconsistent treatment of the many-body problem, at the critical temperature T c . Below T c , we find temperatures which are not critical points, where new superconducting channels open up in the order parameter due to bifurcations in the solutions of the nonlinear gap-equation. We calculate the free energy, entropy, coherence length, critical magnetic fields and Ginzburg–Landau parameter κ. The model is of the extreme type-II variety. At the temperatures where subdominant channels condense, we find cusps in the internal energy and entropy, as well as BCS-like discontinuities in the specific heat. The specific heat anomalies are however weaker than at the true superconducting critical point and argued to be of a different nature.