New results on K physics from NA48 and NA62 experiments

Several analyses from the experiments NA48 and NA62 are presented in this paper, including new measurements with K ± → π±μ+μ− decays, K±μ3 form factors, branching fraction of K± → π+π−e±ν, and precise LFV test with Kl2 decays

Repulsion of Single-well Fundamental Edge Magnetoplasmons in Double Quantum Wells

A {\it microscopic} treatment of fundamental edge magnetoplasmons (EMPs) along the edge of a double quantum well (DQW) is presented for strong magnetic fields, low temperatures, and total filling factor \nu=2. It is valid for lateral confining potentials that Landau level (LL) flattening can be neglected. The cyclotron and Zeeman energies are assumed larger than the DQW energy splitting \sqrt{\Delta^2 +4T^2}, where \Delta is the splitting of the isolated wells and T the tunneling matrix element. %hen calculated unperturbed density profile is sharp at the edge. Using a random-phase approximation (RPA), which includes local and nonlocal contributions to the current density, it is shown that for negligible tunnel coupling 2T << \Delta the inter-well Coulomb coupling leads to two DQW fundamental EMPs which are strongly renormalized in comparison with the decoupled, single-well fundamental EMP. These DQW modes can be modified further upon varying the inter-well distance d, along the z axis, and/or the separation of the wells' edges \Delta y along the y axis. The charge profile of the {\it fast} and {\it slow} DQW mode varies, respectively, in an {\it acoustic} and {\it optical} manner along the y axis and is not smooth on the \ell_{0} scale. For strong tunneling \Delta\alt 2T these DQW modes are essentially modified when \Delta is changed by applying a transverse electric field to the DQW.Comment: Text 18 pages in Latex/Revtex/Preprint format, 2 Postscript figure

Random-phase Approximation Treatment Of Edge Magnetoplasmons: Edge-state Screening And Nonlocality

A random-phase approximation (RPA) treatment of edge magnetoplasmons (EMP) is presented for strong magnetic fields, low temperatures, and integer filling factors \nu. It is valid for negligible dissipation and lateral confining potentials smooth on the scale of the magnetic length \ell_{0} but sufficiently steep that the Landau-level (LL) flattening can be neglected. LL coupling, screening by edge states, and nonlocal contributions to the current density are taken into account. In addition to the fundamental mode with typical dispersion relation \omega\sim q_x \ln(q_{x}), fundamental modes with {\it acoustic} dispersion relation \omega\sim q_x are obtained for \nu>2. For \nu=1,2 a {\bf dipole} mode exists, with dispersion relation \omega\sim q_x^3, that is directly related to nonlocal responses.Comment: Text 12 pages in Latex/Revtex format, 4 Postscript figure

Edge magnetoplasmons in periodically modulated structures

We present a microscopic treatment of edge magnetoplasmons (EMP's) within the random-phase approximation for strong magnetic fields, low temperatures, and filling factor $\nu =1(2)$, when a weak short-period superlattice potential is imposed along the Hall bar. The modulation potential modifies both the spatial structure and the dispersion relation of the fundamental EMP and leads to the appearance of a novel gapless mode of the fundamental EMP. For sufficiently weak modulation strengths the phase velocity of this novel mode is almost the same as the group velocity of the edge states but it should be quite smaller for stronger modulation. We discuss in detail the spatial structure of the charge density of the renormalized and the novel fundamental EMP's.Comment: 8 pages, 4 figure

INTRATHYROID LYMPHOCYTE SUBSETS IN PATIENTS WITH AUTOIMMUNE THYROID DISEASE

Thyroid gland is an easily approachable for direct examination by aspiration biopsy organ. This fact gives a possibility for serial examination of liable disturbances in the immune regulation, connected with autoimmune thyroid disease and their response to the relevant therapy. Twenty-six patients with Basedow's disease (BD) and 12 patients with Hashimoto's thyroiditis (HT) - 34 women and 4 men (mean age 47,3 years) were studied. For determination of superficial markers of intrathyroidal mononuclear cells (ITMC) were used monoclonal antibodies for identification of total T-lymphocytes (CD3+), Т-helper/ inducer cells (CD4+), T-suppressor/cytotoxic eels (CD8+), B-lymphocytes (CD 19+), Nklymphocytes (CD16+56+), activated Т-lymphocytes (CD3+/HLA-DR+), interleukin-2 receptors (CD 25+), and the adhesion molecule ICAM-1 (CD54+). In the patients with BD the main lymphocyte subset was CD3+ with increased number of activated T-lymphocytes and CD4/CD8 ratio (2,22) due to the decreased number of T-suppressor/cytotoxic cells. After the thyreostatic therapy there was a normalization of B-lymphocytes, activated Tlymphocytes and reduction of CD4/CD8 ratio, due to the increased number of T-suppressor/ cytotoxic cells. In patients with HT and hypothyroidism the main cell population consisted of CD3+cells and increased number of CD16+56+ cells as the CD4/CD8 ratio was decreased (0,98). The presence of increased percentage ofIL-2 receptors and of adhesion molecules ICAM-1 in these patients suggests a more pronounced activity of the autoimmune process

FLOWCYTOMETRIC STUDIES OF CELL IMMUNITY IN PATIENTS WITH URAEMIA ON PERIODIC HAEMODIALYSIS AND AFTER RENAL TRANSPLANTATION

The course of a series of kidney diseases is characterized by impaired immunity additionally altered during haemodialysis and after renal transplantation. The study covered 50 patients divided into three groups: 16 patients with chronic renal failure (CRF), 23 ones on periodic haemodialysis (PHD), and 11 after renal transplantation. Flowcytometric immunophenotyping by means of FACS-analysis using monoclonal antibodies was carried out. The investigation aimed at revealing the changes in the cell immunity, activation of surface markers and adhesion molecules in these patients. Statistically significant changes in the expression of 1С AM-1 adhesion molecules were established as followed: CD54+/ CD4+ = 24,8 ± 11,6 (in CRF) against 14,9 ±8,1 (in PHD) atp < 0,05 and CD54+/CD8+ = 17 ± 6,9 (in CRF) against 10,3 ± 4,8 (in PHD) at p < 0,05. A conclusion was drawn that immune response damage in PHD patients resulted mainly from the lowered expression of the adhesion molecules of the ICAM-1 immunoglobulin gene superfamily

Electron correlation effects in a wide channel from the ν=1\nu =1 quantum Hall edge states

The spatial behavior of Landau levels (LLs) for the $nu=1$ quantum Hall regime at the edge of a wide channel is studied in a self-consistent way by using a generalized local density approximation proposed here. Both exchange interaction and strong electron correlations, due to edge states, are taken into account. They essentially modify the spatial behavior of the occupied lowest spin-up LL in comparison with that of the lowest spin-down LL, which is totally empty. The contrast in the spatial behavior can be attributed to a different effective one-electron lateral confining potentials for the spin-split LLs. Many-body effects on the spatially inhomogeneous spin-splitting are calculated within the screened Hartree-Fock approximation. It is shown that, far from the edges, the maximum activation energy is dominated by the gap between the Fermi level and the bottom of the spin-down LL, because the gap between the Fermi level and the spin-up LL is much larger. In other words, the maximum activation energy in the bulk of the channel corresponds to a highly asymmetric position of the Fermi level within the gap between spin-down and spin-up LLs in the bulk. We have also studied the renormalization of the edge-state group velocity due to electron correlations. The results of the present theory are in line with those suggested and reported by experiments on high quality samples.Comment: 9 pages, 4 figure

Collective Edge Excitations In The Quantum Hall Regime: Edge Helicons And Landau-level Structure

Based on a microscopic evaluation of the local current density, a treatment of edge magnetoplasmons (EMP) is presented for confining potentials that allow Landau level (LL) flattening to be neglected. Mode damping due to electron-phonon interaction is evaluated. For nu=1, 2 there exist independent modes spatially symmetric or antisymmetric with respect to the edge. Certain modes, changing shape during propagation, are nearly undamped even for very strong dissipation and are termed edge helicons. For nu > 2 inter-LL Coulomb coupling leads to a strong repulsion of the decoupled LL fundamental modes. The theory agrees well with recent experiments.Comment: 4 pages in Latex/Revtex/two-column format, 3 ps figure

Effect of superficial treatment with new natural antioxidant on salmon (Salmo salar) lipid oxidation

Lipid oxidation is one of the main factors responsible for the quality loss in refrigerated and frozen stored fish products. The aim of the study was to evaluate the effect of superficial treatment of Atlantic salmon (Salmo salar) with dihydroquercetin (DHQ) solutions on the hydrolytic and oxidative changes in fish lipids during refrigerated storage. It was found that treatment with DHQ solution (1.0 g l−1) reduced approximately twice the free fatty acids content of chilled stored salmon. After 11 days of storage at 1 °С, the contents of hydroperoxides (HPO) and 2-thiobarbituric acid reactive substances (TBARS) of these samples decreased with 45.00 and 0.91 mg MDA/kg, respectively. The share of saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), and polyunsaturated fatty acids (PUFA) in control and experimental samples did not differ significantly (P>0.05). Results obtained show that the superficial treatment of salmon with DHQ solution (1.0 g l−1) delayed the hydrolytic and oxidative changes in fish lipids significantly, thus preserving the salmon freshness up to 11 days of storage at 1 °С

Inhomogeneous broadening of tunneling conductance in double quantum wells

The lineshape of the tunneling conductance in double quantum wells with a large-scale roughness of heterointerfaces is investigated. Large-scale variations of coupled energy levels and scattering due to the short-range potential are taken into account. The interplay between the inhomogeneous broadening, induced by the non-screened part of large-scale potential, and the homogeneous broadening due to the scattering by short-range potentials is considered. It is shown that the large inhomogeneous broadening can be strongly modified by nonlocal effects involved in the proposed mechanism of inhomogeneity. Related change of lineshape of the resonant tunneling conductance between Gaussian and Lorentzian peaks is described. The theoretical results agree quite well with experimental data.Comment: 11 pages, 5 figure