2d Gauge Theories and Generalized Geometry

We show that in the context of two-dimensional sigma models minimal coupling of an ordinary rigid symmetry Lie algebra $\mathfrak{g}$ leads naturally to the appearance of the "generalized tangent bundle" $\mathbb{T}M \equiv TM \oplus T^*M$ by means of composite fields. Gauge transformations of the composite fields follow the Courant bracket, closing upon the choice of a Dirac structure $D \subset \mathbb{T}M$ (or, more generally, the choide of a "small Dirac-Rinehart sheaf" $\cal{D}$), in which the fields as well as the symmetry parameters are to take values. In these new variables, the gauge theory takes the form of a (non-topological) Dirac sigma model, which is applicable in a more general context and proves to be universal in two space-time dimensions: A gauging of $\mathfrak{g}$ of a standard sigma model with Wess-Zumino term exists, \emph{iff} there is a prolongation of the rigid symmetry to a Lie algebroid morphism from the action Lie algebroid $M \times \mathfrak{g}\to M$ into $D\to M$ (or the algebraic analogue of the morphism in the case of $\cal{D}$). The gauged sigma model results from a pullback by this morphism from the Dirac sigma model, which proves to be universal in two-spacetime dimensions in this sense.Comment: 22 pages, 2 figures; To appear in Journal of High Energy Physic

Bremsstrahlung on noble gases at low energies

A detailed analysis of the bremsstrahlung spectrum at nonrelativistic electron scattering on argon and xenon is carried out. It is shown that the approximate formulas widely used for the description of bremsstrahlung spectra lead to predictions that significantly differ from the exact results. In the limit when the photon frequency tends to zero, a rigorous proof of the relationship between the spectrum of the bremsstrahlung with a transport cross section of electron scattering on an atom is given. This proof does not require any assumptions about the dependence of the scattering phases on energy. For electron energies lower than the luminescence threshold, it is shown that the predictions for a number of radiated photons obtained by the exact formula are in good agreement with the available experimental data.Comment: 15 pages, 5 figures, new section on the angular distributions is adde

Energy loss for heavy quarks in relation to light partons; is radiative energy loss for heavy quarks anomalous?

The scaling properties of jet suppression measurements are compared for non-photonic electrons ($e^{\pm}$) and neutral pions ($\pi^0$) in Au + Au collisions at $\sqrt{s_{NN}}=200$ GeV. For a broad range of transverse momenta and collision centralities, the comparison is consistent with jet quenching dominated by radiative energy loss for both heavy and light partons. Less quenching is indicated for heavy quarks via $e^{\pm}$; this gives an independent estimate of the transport coefficient $\hat{q}$ that agrees with its magnitude obtained from quenching of light partons via $\pi^0$'s.Comment: Published versio

The BaBar Event Building and Level-3 Trigger Farm Upgrade

The BaBar experiment is the particle detector at the PEP-II B-factory facility at the Stanford Linear Accelerator Center. During the summer shutdown 2002 the BaBar Event Building and Level-3 trigger farm were upgraded from 60 Sun Ultra-5 machines and 100MBit/s Ethernet to 50 Dual-CPU 1.4GHz Pentium-III systems with Gigabit Ethernet. Combined with an upgrade to Gigabit Ethernet on the source side and a major feature extraction software speedup, this pushes the performance of the BaBar event builder and L3 filter to 5.5kHz at current background levels, almost three times the original design rate of 2kHz. For our specific application the new farm provides 8.5 times the CPU power of the old system.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics (CHEP03), La Jolla, Ca, USA, March 2003, 4 pages, 1 eps figure, PSN MOGT00

THE EFFECT OF MOTIVATION ON THE MOTOR ACTIVITIES OF STUDENTS UNDER DIFFERENT PHYSICAL EDUCATION APPROACHES

Introduction. Motivation of pupils is the principal aspect in successful physical education. One of the main objectives of a physical-education teacher is to create in pupils a strong desire to consciously and voluntarily carry out regular physical exercises and develop the potential to work independently. The aim of the research was to show the influence of various approaches to the organization of sports activities on motivation leading to physical activity in young men aged 16–18. Methodology and research methods. The methodological base of the research involved a personally-oriented educational concept combining differentiated and kinesiological approaches to physical education. The research was carried out in phases using annual and longitudinal tests to evaluate students’ knowledge and skills. Levels of general intelligence were estimated using the I-S-T 2000R test as adapted by L. A. Yasyukova. Formal-dynamic characteristics of individuality were studied using the method developed by V. M. Rusalov. In order to evaluate motivation for the realization of motor activity, a specially-designed questionnaire was used. IBM SPSS Statistics 22 and Microsoft Excel software programs were employed for statistical processing of primary experimental material. Results and scientific novelty. A comparative analysis of the personal characteristics of senior school students and 1st year students (177 people) identified heterochronism in the development of standard motive and mental abilities of young people. It was observed that a lack of synchronism in the formation of separate functional systems in an organism causes a different attitude of school students to physical exercises implemented through an integrated program and standard approach without taking into account individual characteristics of young men. As compared with their peers, motivation to sport activities is initially higher among pupils with higher motor function. A formative level of general intelligence is lower due to students’ potential success when performing a wide complex of activities required by the physical culture curriculum. However, allowing free choice in sport specialization significantly increases the motivation of young people who are physically weaker but who are more intellectually developed than their peers. Practical significance. The research outcomes serve as scientific justification for the more extensive introduction of sports-oriented approach into educational institutions when organizing physical education. A sports-oriented approach is focused on preferences and interests of each student. The approach provides a free choice of the most attractive kinds of activity which gives a feeling of satisfaction and self-confidence, and consequently, enhances motivation to physical selfimprovement through visiting fitness centres and gyms which, in turn, will ensure good health in the future. Введение. Важнейший фактор эффективности занятий физической культурой – мотивация учащихся. Сформировать у воспитанников устойчивое желание и потребность выполнять регулярно, добровольно, осознанно и в перспективе преимущественно самостоятельно физические упражнения – одна из основных задач преподавателя физкультуры. Цель статьи – продемонстрировать влияние различных подходов к организации спортивных занятий на мотивацию к двигательной активности юношей 16–18-летнего возраста. Методология и методики. Методологической базой исследования были положения личностно-ориентированной концепции обучения, а также дифференцированного и кинезиологического подходов к физическому воспитанию. Поэтапная работа проводилась методами «погодичных» и «продольных» (лонгитюдных) срезов. Уровни общего интеллекта испытуемых оценивались посредством теста Р. Амтхауэра в адаптации Л. А. Ясюковой. Формально-динамические свойства индивидуальности учащихся определялись с помощью методики В. М. Русалова. При выявлении уровня мотивации респондентов применялся авторский опросник. Для статистической обработки первичного экспериментального материала были задействованы программы SPSS Statistics 22 и Microsoft Excel. Результаты и научная новизна. На основе сравнительного анализа личностных характеристик старшеклассников общеобразовательной школы и студентов 1-х курсов вуза, совокупная выборка которых составила 177 человек, установлен гетерохронизм в развитии кондиционных двигательных и интеллектуальных способностей молодых людей. Доказывается, что отсутствием синхронности в становлении отдельных функциональных систем организма обусловлено разное отношение школьников к занятиям физкультурой, организованных на основе комплексного программно-нормативного подхода, не учитывающего индивидуальные особенности юношей. Мотивация к занятиям изначально выше у учащихся с более высокими двигательными показателями и менее низким, в сравнении со сверстниками, уровнем сформированности общего интеллекта, что объясняется их потенциальной успешностью выполнения широкого комплекса требований программы по физической культуре. Однако при свободном выборе спортивной специализации в вузе у молодых людей, отстающих в физической подготовке, но опережающих ровесников в интеллектуальном развитии, мотивация к спортивным занятиям существенно возрастает. Практическая значимость. Итоги исследования могут служить научным обоснованием внедрения в учебный процесс спортивно-ориентированного подхода к физвоспитанию, принимающего во внимание предпочтения и интересы каждого обучающегося и предоставляющего свободный выбор наиболее привлекательных для него видов деятельности, выполнение которых дает чувство удовлетворенности и уверенности в собственных силах, а следовательно, усиливает мотивацию к физическому самосовершенствованию и посещению спортивных залов и площадок, что, в свою очередь, является залогом поддержки крепкого здоровья

МАРКЕТИНГОВЫЙ ПОДХОД К ИССЛЕДОВАНИЮ ГОРОДСКИХ ПАССАЖИРОПОТОКОВ

The article is devoted to the organization of passenger flows of public transport in Yaroslavl. A new method for the study is proposed, based on the marketing concept. The field portion of the program was accomplished in May 2012. The results of the study on the transport situation allowed offering correction methods that optimize the route network of the city.Despite localization of problems under review, which was determined by the necessity to apply and verify the methods in real situation, the approaches and techniques suggested by the researcher can be generalized and used for other locations.Статья посвящена проблемам организации пассажиропотоков общественного транспорта в Ярославле. Взамен традиционных способов изучения спроса на городские пассажирские перевозки обоснован новый метод исследования, базирующийся на маркетинговой концепции. Полевая часть программы реализована в мае 2012 года. Результаты изучения транспортной ситуации позволили предложить коррекции, оптимизирующие маршрутную сеть города

Evidence of phi --> pi0 pi0 gamma and phi --> pi0 eta gamma decays in SND experiment at VEPP-2M

Preliminary results on the study of e+e- --> phi(1020) --> pi0 pi0 gamma, eta pi0 gamma processes from SND experiment at VEPP-2M collider in Novosibirsk are presented. Branching ratios of rare radiative phi --> pi0 pi0 gamma and phi --> pi0 eta gamma decays are measured: B(phi --> pi0 pi0 gamma ) = (1.1 +- 0.2) * 10^-4 (invariant mass (pi0 pi0) < 800 MeV), B(phi --> eta pi0 gamma ) = (1.3 +- 0.5) * 10^-4.Comment: Talk at the HADRON97 conference, BNL, Aug 24-30 1997; LaTeX, 4 pages, 4 eps figure