Event shapes in e+e- annihilation and deep inelastic scattering

This article reviews the status of event-shape studies in e+e- annihilation and DIS. It includes discussions of perturbative calculations, of various approaches to modelling hadronisation and of comparisons to data.Comment: Invited topical review for J.Phys.G; 40 pages; revised version corrects some nomenclatur

Measurement of e⁺e⁻-->e⁺e⁻ and e⁺e⁻-->gammagamma at energies up to 36.7 GeV

e+e- +- +- ... + e e und e e + yy wurden bel Energlen zwischen 33.0 und 36.7 GeV gemessen. Die Ergebnisse stimmen mit den Vorhersagen der Quantenelektrodynamik überein. Ein Vergleich mit dem Standardmodell der elektroschwachen Wechselwirkung liefert sin 20w= 0.25 ± 0.13

Resolved Photon Contributions to Leptoquark Production in e+e−e^+ e^- and eγe\gamma Collision

We calculate the resolved photon contribution to leptoquark production at $e\gamma$ colliders for the center of mass energies $\sqrt s=500$~GeV and 1~TeV. We also calculate the resolved photon contribution to leptoquark production at $e^+ e^-$ colliders for the center of mass energies $\sqrt{s} = 1$~and~2~TeV. In both cases we find that these contributions are considerably larger than the standard contributions considered in the literature.Comment: 9 pages (5 postscript figures in separate uuencoded file), OCIP/C 93-1

A three-step numerical approximant based on block hybrid backward differentiation formula for stiff system of ordinary differential equation

We present results of an analysis of the reaction $γγ→ωϱ$ in the two-photon process $e^+e^−→ϵ^+e^−2π^+2π^−π^0$ in the untagged mode. The cross section is largely compatible with previous determinations; however, we do not confirm the enhancement claimed at 1.9 GeV. All observed ω's are accompanied by ϱ's in the recoiling ππ spectrum. An angular correlation analysis shows that the data is not dominated by a single spin-parity state, thus establishing severe constraints on $qqqq$ models which predict $JP= 2^+$

Алгоритм сжатия на основе вычисления скорости изменения ультразвукового сигнала

The intermittency structure of multihadronic e+e- annihilation is analyzed by evaluating the factorial moments F2-F5 in three-dimensional Lorentz invariant phase space as a function of the resolution scale. We interpret our data in the language of fractal objects. It turns out that the fractal dimension depends on the resolution scale in a way that can be attributed to geometrical resolution effects and dynamical effects, such as the pi-O Dalitz decay. The LUND 7.2 hadronization model provides an excellent description of the data. There is no indication of unexplained multiplicity fluctuations in small phase space regions

Разработка модульного стенда физического подобия для изучения гидротехнических систем

В рамках данной работы проведен обзор и анализ образовательных стендов, сформулирована концепция модульного стенда физического подобия, разработаны функциональные схемы двух модулей, в соответствии с которыми подобраны основные элементы. Для первого модуля предоставлены принципиальная схема и демонстрационный алгоритм работы.In this work, a review and analysis of educational booths, formulated the concept of modular stand physical similarity, developed functional diagrams of the two modules, in accordance with which the selected basic elements. For the first module, a schematic diagram and a demonstration algorithm are provided

Накопление газообразных продуктов деления и соединений в микрокапсулированном топливе в сверхдлинных кампаниях

The production of b and c quarks in $e^+e^−$ annihilation has been studied with the CELLO detector in the range from 35 GeV up to the highest PETRA energies. The heavy quarks have been tagged by their semileptonic decays. The charge asymmetries for b quarks at 35 and 43 GeV have been found to be $A^b=−(22.2±8.1)$, respectively, using a method incorporating jet variables and their correlations for the separation of the heavy quarks from the back ground of the lighter quarks. For c quarks we obtain $A^c=−(12.9±8.8)$ and $A^c=+(7.7±14.0)$, respectively. The axial vector coupling constants of the heavy quarks c and b are found to be $a^c=+(0.29±0.46)$ and $a^b=−(1.15±0.41)$ taking $B^0 \bar(B^0) B^0\bar(B^0)$ mixing into account. The results are in agreement with the expectations from the standard model

Measurement of inclusive γπ0\gamma \pi^0 and η production in e+e−e^+e^- annihilation at s\sqrt {s}=35 GeV

We have measured the inclusive production of γ, π0 and η ine+e− annihilation at the center of mass energy of 35 GeV. The differential cross sections, extended to the kinematical limit and measured with high accuracy, are found to be in good agreement with previously reported results. Using the measured spectra we determine the average multiplicity for each of these particle species

A measurement of the π0,η\pi^0, \eta and η′\eta′ electromagnetic form factors

We present measurement of the $π^0γ^*γ, ηγ^*γ$ and $η′γ^*γ$ form factors. The π0-form factor is for the first time observed in the space-like region. The transition form factor of the $η^-$ meson is determined from its decay modes $π^+π^−π^0, π^+π^−γ$ and the neutral decay mode γγ. The decay of the η′ is observed in the decay channels ργ, ηπ+π− with η→γγ and in the four charged prong final state stemming from $ηπ^+π^−$ with the η decaying into $π^+π^−(π^0/γ)$. All form factors agree well with a simple ρ-pole predicted by the vector meson dominance model and also with the QCD inspired Brodsky-Lepage model

Exclusive τ\tau decays with the CELLO detector at PETRA

We present high precision results from an analysis of all major τ branching ratios, determined simultaneously in the same experiment. The results are based on 6064 τ decays observed at s√=35GeVs=35GeV , using the CELLO detector at PETRA. The sum of the measured exclusive branching ratios saturates the total τ decay width. In a comparison with the topological branching ratios measured recently by CELLO, the sums of the respective exclusive branching ratios are found to saturate the inclusive fractions. Our results are in good general agreement with existing measurements. However, the decay fractions for$τ^−→π^−π^+π^−vτ$, and $π^−→π^−π^0π^0vτ$ are larger than the present world averages. All measured branching ratios are in good agreement with the expectations from a standard τ lepton