Non-Abelian Vortices, Super-Yang-Mills Theory and Spin(7)-Instantons

We consider a complex vector bundle E endowed with a connection A over the eight-dimensional manifold R^2 x G/H, where G/H = SU(3)/U(1)xU(1) is a homogeneous space provided with a never integrable almost complex structure and a family of SU(3)-structures. We establish an equivalence between G-invariant solutions A of the Spin(7)-instanton equations on R^2 x G/H and general solutions of non-Abelian coupled vortex equations on R^2. These vortices are BPS solitons in a d=4 gauge theory obtained from N=1 supersymmetric Yang-Mills theory in ten dimensions compactified on the coset space G/H with an SU(3)-structure. The novelty of the obtained vortex equations lies in the fact that Higgs fields, defining morphisms of vector bundles over R^2, are not holomorphic in the generic case. Finally, we introduce BPS vortex equations in N=4 super Yang-Mills theory and show that they have the same feature.Comment: 14 pages; v2: typos fixed, published versio

Флуктуационная теория зарождения защитных нанослоёв на металлах в агрессивных электролитах

In this article the mathematical model of inhibitiring nanolayer is exposed. The latter is formed by the mechanism of heterogeneous germ-formation on energetically non-uniformed surface S of the real anodic dissolution metal. There considered the rise of a fluctuation ΔVф of electrolyte on the surface S. Their saturation by the ions components is described by the classical equations of the ionic mass transfer. Every volume ΔVф can be a mother phase for the germ of inhibitor. There considered the kinetics of germ-formation and the evolution of germ given by the change of the mother phase.В статье изложена математическая модель ингибирующего нанослоя. Он формируется по механизму гетерогенного зародышеобразования на энергетически неоднородной поверхности S реального анодно-растворяющегося металла. Рассмотрено возникновение на S флюктуации ΔVф электролита, насыщение которых ионными компонентами описывается классическими уравнениями ионного массопереноса. Каждый объём ΔVф может быть материнской фазой для зародыша ингибитора. Рассмотрена кинетика зародышеобразования и эволюция зародышей, обусловленная изменением материнской фазы

Chronic tonsillitis in adolescents: clinical features and the role of ultrasound diagnosis in the northern region of Ukraine

Background. Chronic tonsillitis is the most common disease among children and adolescents in the structure of pathology of the ENT organs. Untimely diagnosis and irrational treatment lead to decompensation of chronic tonsillitis and the development of lesions of many organs and systems of the child’s body of tonsillogenic origin. The aim of the work was to study the clinical features and ultrasound changes of the palatine tonsils in adolescents with chronic tonsillitis. Materials and methods. We have examined 47 children aged 13 to 17 years suffering from chronic tonsillitis: group I — 27 patients with compensated chronic tonsillitis, group II — 20 patients suffering from decompensated chronic tonsillitis. The control group consisted of 16 practically healthy children, representative in terms of age and gender. We used clinical methods, ultrasonography of the palatine tonsils, and statistical methods. The study was approved by the Institutional Bioethics Committee and it conforms to the principles outlined in the Declaration of Helsinki. Results. According to the results of an ultrasound examination of the palatine tonsils in children with chronic tonsillitis, the main changes were an increase in their transverse dimensions by more than 15 mm, deepening of lacunae, thickening of the capsule, fibrous changes. In addition, in patients with tonsillogenic lesions of the cardiovascular system and a decompensated form of chronic tonsillitis, the pathological signs of the disease according to ultrasound were more significant and were manifested by unclear contours, increased echogenicity, heterogeneous hyperechoic structure, diffuse fibrous and cystic changes of the palatine tonsils. Conclusions. Ultrasonography of the palatine tonsils is a non-invasive, painless, accessible and informative method for studying the structure of the tonsils in normal and pathological conditions. It allows for a more thorough assessment of their changes in compensated and decompensated forms of chronic tonsillitis

Nonperturbative equation of state of quark-gluon plasma. Applications

The vacuum-driven nonperturbative factors $L_i$ for quark and gluon Green's functions are shown to define the nonperturbative dynamics of QGP in the leading approximation. EoS obtained recently in the framework of this approach is compared in detail with known lattice data for $\mu=0$ including $P/T^4$, $\epsilon/T^4$, $\frac{\epsilon-3P}{T^4}$. The basic role in the dynamics at T\la 3T_c is played by the factors $L_i$ which are approximately equal to the modulus of Polyakov line for quark $L_{fund}$ and gluon $L_{adj}$. The properties of $L_i$ are derived from field correlators and compared to lattice data, in particular the Casimir scaling property $L_{adj} =(L_{fund})^{\frac{C_2(adj)}{C_2(fund)}}$ follows in the Gaussian approximation valid for small vacuum correlation lengths. Resulting curves for $P/T^4$, $\epsilon/T^4$, $\frac{\epsilon-3P}{T^4}$ are in a reasonable agreement with lattice data, the remaining difference points out to an effective attraction among QGP constituents.Comment: 20 pages, 6 figure

Damping of phase fluctuations in superfluid Bose gases

Using Popov's hydrodynamic approach we derive an effective Euclidean action for the long-wavelength phase fluctuations of superfluid Bose gases in D dimensions. We then use this action to calculate the damping of phase fluctuations at zero temperature as a function of D. For D >1 and wavevectors | k | << 2 mc (where m is the mass of the bosons and c is the sound velocity) we find that the damping in units of the phonon energy E_k = c | k | is to leading order gamma_k / E_k = A_D (k_0^D / 2 pi rho) (| k | / k_0)^{2 D -2}, where rho is the boson density and k_0 =2 mc is the inverse healing length. For D -> 1 the numerical coefficient A_D vanishes and the damping is proportional to an additional power of |k | /k_0; a self-consistent calculation yields in this case gamma_k / E_k = 1.32 (k_0 / 2 pi rho)^{1/2} |k | / k_0. In one dimension, we also calculate the entire spectral function of phase fluctuations.Comment: 6 pages, 4 figures, published versio

Spin asymmetry A_1^d and the spin-dependent structure function g_1^d of the deuteron at low values of x and Q^2

We present a precise measurement of the deuteron longitudinal spin asymmetry A_1^d and of the deuteron spin-dependent structure function g_1^d at Q^2 < 1 GeV^2 and 4*10^-5 < x < 2.5*10^-2 based on the data collected by the COMPASS experiment at CERN during the years 2002 and 2003. The statistical precision is tenfold better than that of the previous measurement in this region. The measured A_1^d and g_1^d are found to be consistent with zero in the whole range of x.Comment: 17 pages, 10 figure

Gluon polarization in the nucleon from quasi-real photoproduction of high-pT hadron pairs

We present a determination of the gluon polarization Delta G/G in the nucleon, based on the helicity asymmetry of quasi-real photoproduction events, Q^2<1(GeV/c)^2, with a pair of large transverse-momentum hadrons in the final state. The data were obtained by the COMPASS experiment at CERN using a 160 GeV polarized muon beam scattered on a polarized 6-LiD target. The helicity asymmetry for the selected events is = 0.002 +- 0.019(stat.) +- 0.003(syst.). From this value, we obtain in a leading-order QCD analysis Delta G/G=0.024 +- 0.089(stat.) +- 0.057(syst.) at x_g = 0.095 and mu^2 =~ 3 (GeV}/c)^2.Comment: 10 pages, 3 figure

The Deuteron Spin-dependent Structure Function g1d and its First Moment

We present a measurement of the deuteron spin-dependent structure function g1d based on the data collected by the COMPASS experiment at CERN during the years 2002-2004. The data provide an accurate evaluation for Gamma_1^d, the first moment of g1d(x), and for the matrix element of the singlet axial current, a0. The results of QCD fits in the next to leading order (NLO) on all g1 deep inelastic scattering data are also presented. They provide two solutions with the gluon spin distribution function Delta G positive or negative, which describe the data equally well. In both cases, at Q^2 = 3 (GeV/c)^2 the first moment of Delta G is found to be of the order of 0.2 - 0.3 in absolute value.Comment: fits redone using MRST2004 instead of MRSV1998 for G(x), correlation matrix adde

A new measurement of the Collins and Sivers asymmetries on a transversely polarised deuteron target

New high precision measurements of the Collins and Sivers asymmetries of charged hadrons produced in deep-inelastic scattering of muons on a transversely polarised 6LiD target are presented. The data were taken in 2003 and 2004 with the COMPASS spectrometer using the muon beam of the CERN SPS at 160 GeV/c. Both the Collins and Sivers asymmetries turn out to be compatible with zero, within the present statistical errors, which are more than a factor of 2 smaller than those of the published COMPASS results from the 2002 data. The final results from the 2002, 2003 and 2004 runs are compared with naive expectations and with existing model calculations.Comment: 40 pages, 28 figure

Measurement of the Spin Structure of the Deuteron in the DIS Region

We present a new measurement of the longitudinal spin asymmetry A_1^d and the spin-dependent structure function g_1^d of the deuteron in the range 1 GeV^2 < Q^2 < 100 GeV^2 and 0.004< x <0.7. The data were obtained by the COMPASS experiment at CERN using a 160 GeV polarised muon beam and a large polarised 6-LiD target. The results are in agreement with those from previous experiments and improve considerably the statistical accuracy in the region 0.004 < x < 0.03.Comment: 10 pages, 6 figures, subm. to PLB, revised: author list, Fig. 4, details adde