Nikolai Nikovaevich Bogolyubov – Great Scientist and Humanist of the XX-th Century

August 21, 2009 marked the hundredth anniversary of Nikolai Nikolaevich Bogoliubov,World Science Classic. Bogoliubov’s name entered forever the history of civilization. He was a Scientist of encyclopedic dimensions, one of the Creators of modern theoretical and mathematical physics, Founder of a constellation of scientific schools and of the widely known journal of Theoretical and Mathematical Physics. The logotype М∩Ф introduced by him, in Cyrillic, became the brand of a series of International Congresses on Mathematical Physics. (The last, XVI Congress of this series, was held in Prague, 2009, 3–8 August). The present paper is a short review of N.N. Bogoliubov’s life in science. His original papers, quoted in this review, can be found in [1]. For a colorful biography of the Master, we refer to Ref. [2].21 серпня 2009 року вiдзначалося столiття вiд дня народження Миколи Миколайовича Боголюбова – класика свiтової науки. Iм’я Боголюбова назавжди увiйшло в iсторiю цивiлiзацiї. Вiн був вченим енциклопедичного масштабу, одним з творцiв сучасної теоретичної i математичної фiзики, засновником сузiр’я наукових шкiл, а також широко вiдомого журналу “Теоретична i математична фiзика”. Логотип Ф∩М, запропонований ним, став знаком серiї мiжнародних конгресiв з математичної фiзики (останнiй, XVI-й Конгрес цiєї серiї вiдбувся у Празi 3–8 серпня 2009 року). Ця стаття є коротким оглядом основних наукових результатiв М.М. Боголюбова. Оригiнальнi роботи М.М. Боголюбова, якi згадуються в оглядi, можна знайти в його збiрцi творiв [1], а коротку бiографiю – в роботi [2]

The Pomeron in Exclusive J/ψJ/\psi Vector Meson Production

An earlier developed model for vector meson photoproduction, based on a dipole Pomeron exchange, is extended to electroproduction. Universality of the non linear Pomeron trajectory is tested by fitting the model to ZEUS and H1 data as well as to CDF data on $\bar pp$ elastic scatteringComment: 6 pages, 5 figures, talk presented by A. Prokudin at Photon 2003, Frascati, Italy, 7-11 April 200

Finite sum of gluon ladders and high energy cross sections

A model for the Pomeron at $t=0$ is suggested. It is based on the idea of a finite sum of ladder diagrams in QCD. Accordingly, the number of $s$-channel gluon rungs and correspondingly the powers of logarithms in the forward scattering amplitude depends on the phase space (energy) available, i.e. as energy increases, progressively new prongs with additional gluon rungs in the $s$-channel open. Explicit expressions for the total cross section involving two and three rungs or, alternatively, three and four prongs (with $\ln^2(s)$ and $\ln^3(s)$ as highest terms, respectively) are fitted to the proton-proton and proton-antiproton total cross section data in the accelerator region. Both QCD calculation and fits to the data indicate fast convergence of the series. In the fit, two terms (a constant and a logarithmically rising one) almost saturate the whole series, the $\ln^2(s)$ term being small and the next one, $\ln^3(s)$, negligible. Theoretical predictions for the photon-photon total cross section are also given.Comment: 18 pages, LaTeX, 2 EPS figures, uses axodraw.st

Diffractive Deep-Inelastic Scattering

Diffractive deep inelastic events with a large rapidity gap are analyzed by using a Regge model for the pomeron flux and a gluonic content for the pomeron. Contrary to the expectations, the simplest assumption for the pomeron trajectory gives the best agreement with the data on the ratio of diffractive to the total number of events. In this case the main properties of the model are described by an analytic expression.Comment: 18 pages (postcript file

The Pomeron In Exclusive Vector Meson Production

An earlier developed model for vector meson photoproduction, based on a dipole Pomeron exchange, is extended to electroproduction. Universality of the non linear Pomeron trajectory is tested by fitting the model to ZEUS and H1 data as well as to CDF data on $\bar pp$ elastic scattering.Comment: 12 pages, 13 figure

Study of one-zone subcritical amplifiers of neutron flux involving enriched uranium

We examine the main aspects of the construction of subcritical systems able to multiply neutrons from the external source with emphasis on the choice of the neutron source and optimization of the parameters of the subcritical system. We present results of our calculations of neutron flux amplification factor for the one-zone spherical systems made up of the enriched uranium, water solution of the enriched uranium, and for the spherical enriched uranium system with reflector.Розглянуто основні аспекти побудови підкритичних систем, здатних розмножувати нейтрони зовнішнього джерела, що стосуються вибору джерела нейтронів і оптимізації параметрів підкритичної системи. Представлено результати розрахунків коефіцієнтів посилення для однозонної сферичної системи зі збагаченого урану, однозонної сферичної системи з розчину збагаченого урану у воді, а також для системи збагаченого урану, що складається зі сферичної активної зони, і відбивача.Рассмотрены основные аспекты построения подкритических систем, способных усиливать нейтроны внешнего источника, касающиеся выбора источника нейтронов и оптимизации параметров подкритической системы. Представлены результаты расчетов коэффициентов усиления для однозонной сферической системы из обогащенного урана, однозонной сферической системы из раствора обогащенного урана в воде, а также для системы обогащенного урана, состоящей из сферической активной зоны и отражателя

Can supercooling explain the HBT puzzle?

Possible hadronization of supercooled QGP, created in heavy ion collisions at RHIC and SPS, is discussed within a Bjorken hydrodynamic model. Such a hadronization is expected to be a very fast shock-like process, what, if hadronization coincides or shortly followed by freeze out, could explain a part of the HBT puzzle, i.e. the flash-like particle emission ($R_{out}/R_{side}\approx 1$). HBT data also show that the expansion time before freeze out is very short ($\sim 6-10 fm/c$). In this work we discuss question of supercooled QGP and the timescale of the reaction.Comment: 9 pages, 2 figure

Effective Functional Form of Regge Trajectories

We present theoretical arguments and strong phenomenological evidence that hadronic Regge trajectories are essentially nonlinear and can be well approximated, for phenomenological purposes, by a specific square-root form.Comment: 29 pages, LaTeX. Published versio

Statistical Hadronization of Supercooled Quark-Gluon Plasma

The fast simultaneous hadronization and chemical freeze out of supercooled quark-gluon plasma, created in relativistic heavy ion collisions, leads to the re-heating of the expanding matter and to the change in a collective flow profile. We use the assumption of statistical nature of the hadronization process, and study quantitatively the freeze out in the framework of hydrodynamical Bjorken model with different quark-gluon plasma equations of state.Comment: 7 pages, 3 figure

Non-Perturbative QCD Treatment of High-Energy Hadron-Hadron Scattering

Total cross-sections and logarithmic slopes of the elastic scattering cross-sections for different hadronic processes are calculated in the framework of the model of the stochastic vacuum. The relevant parameters of this model, a correlation length and the gluon condensate, are determined from scattering data, and found to be in very good agreement with values coming from completely different sources of information. A parameter-free relation is given between total cross-sections and slope parameters, which is shown to be remarkably valid up to the highest energies for which data exist.Comment: 60 pages, Heidelberg preprin