Axial anomaly and the interplay of quark loops with pseudoscalar and vector mesons in the gamma* --> pi+ pi0 pi- process

Motivated by the ongoing measurements of the Primakoff process pi- gamma* --> pi- pi0 by COMPASS collaboration at CERN, the transition form factor for the canonical anomalous process gamma* --> pi+ pi0 pi- is calculated in a constituent quark loop model. The simplest contribution to this process is the quark "box" amplitude. In the present paper we also explicitly include the vector meson degrees of freedom, i.e., the rho and the omega, thus giving rise to additional, resonant contributions. We find that in order to satisfy the axial anomaly result, a further subtraction in the resonant part is needed. The results are then compared with the vector meson dominance model as well as the Dyson--Schwinger calculations, the chiral perturbation theory result, and the available data.Comment: 21 pages, 8 eps figures, revtex4, a factor of 2 in resonant contribution corrected, three figures revised and one added, discussion enlarged and references adde

Absorption of microdroplets by layered porous media

Paper presented at the 6th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 30 June - 2 July, 2008.The subject of this paper is the sequential absorption of two droplets at its arbitrary location on the surface of single- and double-layer porous media. The consideration is based on simultaneous solution of the equations describing liquid flow in the droplet and equations of unsteady filtration in the porous medium. The layers of porous medium were characterized by effective permeability coefficients dependent on porosity and pore size. The change in the droplet shape during absorption and the propagation of absorbed fluid in a porous medium are the output data of the problem. The effect of porous medium structure parameters and relative location of droplets on the rate of absorption and distribution of absorbed liquids is analyzed using the numerical experiment. It is shown that the presence of the second layer can significantly affect the duration and result of droplet absorption. The ratio of the pore size in the layers is found to be the main parameter that governs the effect of the second layer.vk201

Триасовый нефтегазоносный комплекс – потенциальный объект для прироста ресурсной базы Западной Сибири

The paper considers the results of analysis of information on the distribution of the Triassic deposits on the Western Siberia territory. It was established that the Triassic deposits are at different stages of catagenesis. Analysis of sediments distribution allowed defining that the highest potential for oil content is at the central and southern parts, and for gas at the northern area. It is assumed that the deep-seated Triassic deposits at the north of Western Siberia may be considered as a new potential gas-bearing object.Приводятся данные о распространении триасовых отложений на территории Западной Сибири. В связи с тем, что триасовые отложения находятся на разных стадиях катагенеза, установлена следующая закономерность: нефтеносны ее центральная и южная части, а газоносна – северная. Сделано предположение о том, что глубокопогруженные триасовые отложения севера Западной Сибири могут быть новым потенциальным газоносным объектом

Diagnostic opportunities of computer bronchophonography in bronchial asthma in children 5 years and younger

The aim of the research was to study the possibilities of computer bronhofonography (KBFG) in primary diagnostics and evaluation of basic therapy of bronchial asthma (BA) in children 5 years and younger. 53 children 3-5 years with BA, 39 children of the same age with acute obstructive bronchitis (AOB) or prolonged cough after suffering respiratory viral infection were examined. The study was conducted at intervals of one week for 6 weeks. KBFG with bronchodilatation test carried out at intervals of one week for 6 weeks. It has been established that the presence of hidden reversible bronchial obstruction without clinical spptoms of BA is indication for correction of basic therapy towards its reinforcement. The risk group by BA in a cohort of children with GPG and prolonged cough-registration hidden reversible obstruction of one month after the heavily acute period of diseases was defined.Целью работы явилось исследование возможностей компьютерной бронхофонографии (КБФГ) в первичной диагностике и оценке эффективности базисной терапии бронхиальной астмы (БА) у детей 5 лет и младше. Обследованы 53 ребёнка 3-5 лет с БА, 39 детей того же возраста с острым обструктивным бронхитом (00Б) или длительным кашлем после перенесенной респираторной вирусной инфекции. КБФГ с бронходилатационным тестом проводилось с интервалом в одну неделю в течение 6 недель. Установлено, что наличие скрытой обратимой бронхиальной обструкции без клинических симптомов БА является показанием для коррекции базисной терапии в сторону её усиления. Определена группа риска по БА в когорте детей с 00Б или длительным кашлем - регистрация скрытой обратимой обструкции через один месяц после купирования острого периода заболевания

No Sommerfeld resummation factor in e+e- -> ppbar ?

The Sommerfeld rescattering formula is compared to the e+e- -> ppbar BaBar data at threshold and above. While there is the expected Coulomb enhancement at threshold, two unexpected outcomes have been found: |G^p (4M_p^2)|= 1, like for a pointlike fermion, and moreover data show that the resummation factor in the Sommerfeld formula is not needed. Other e+e- -> baryon-antibaryon cross sections show a similar behavior near threshold.Comment: 9 pages, 6 figure

Where is the pseudoscalar glueball ?

The pseudoscalar mesons with the masses higher than 1 GeV are assumed to belong to the meson decuplet including the glueball as the basis state supplementing the standard $SU(3)_F$ nonet of light $q\bar{q}$ states $(u,d,s)$. The decuplet is investigated by means of an algebraic approach based on hypothesis of vanishing the exotic $SU(3)_F$ commutators of "charges" and their time derivatives. These commutators result in a system of equations determining contents of the isoscalar octet state in the physical isoscalar mesons as well as the mass formula including all masses of the decuplet: $\pi(1300)$, K(1460), $\eta(1295)$, $\eta(1405)$ and $\eta(1475)$. The physical isoscalar mesons $\eta_i$, are expressed as superpositions of the "ideal" $q\bar{q}$ states ($N$ and $S$) and the glueball $G$ with the mixing coefficient matrix following from the exotic commutator restrictions. Among four one-parameter families of the calculated mixing matrix (numerous solutions result from bad quality of data on the $\pi(1300)$ and K(1460) masses) there is one family attributing the glueball-dominant composition to the $\eta(1405)$ meson. Similarity between the pseudoscalar and scalar decuplets, analogy between the whole spectra of the $0^{-+}$ and $0^{++}$ mesons and affinity of the glueball with excited $q\bar{q}$ states are also noticed.Comment: 18 pp., 2. figs., 2 tabs.; Published version. One of the authors withdraws his nam

Theoretical optimization of the shape and size of adsorbent grains for associated petroleum gas drying

The shape of adsorbent grains used for drying hydrocarbon gas flows at a reduced hydraulic resistance of their beds are theoretically optimized. A two-velocity model of gas flow in fixed beds consisting of differently shaped holed particles is used for calculations at typical parameters of the associated petroleum gas drying process. It is shown that the optimum shape of a grain is a four-spoke ring. At an equivalent diameter of 3 mm, such a grain is 6.154 × 6.154 mm in size, and its walls and baffles are 1.026 mm thick