1,275 research outputs found
Production of the Doubly Charmed Baryons at the SELEX experiment -- The double intrinsic charm approach
The high production rate and of the doubly
charmed baryons measured by the SELEX experiment is not amenable to
perturbative QCD analysis. In this paper we calculate the production of the
doubly heavy baryons with the double intrinsic charm Fock states whose
existence is rigorously predicted by QCD. The production rate and the
longitudinal momentum distribution are both reproduced. We also show that the
production rates of the doubly charmed baryons and double production
observed by NA3 collaboration are comparable. Recent experimental results are
reviewed. The production cross section of the doubly charmed baryons at a
fixed-target experiment at the LHC is presented.Comment: The text is as published in Physics Letters
Future of B Physics at CDF and DO
In this contribution to the panel discussion on ``The Future of Hadron B
Experiments'' held at the 8th International Conference on B Physics at Hadron
Machines (Beauty 2002) at Santiago de Compostela, Spain, we explore the physics
potential for B physics at CDF and DO in five years and beyond. After a brief
introduction to precision flavour physics, we concentrate our discussion on the
future of CP violation by evaluating the prospects for measuring the CKM angles
beta, gamma and alpha at the Tevatron Collider experiments CDF and DO by the
end of Run II.Comment: Posting for the archives: Contribution to Panel Discussion on "The
Future of Hadron B Experiments". Pub. Proceedings Beauty 2002: 8th
International Conference on B Physics at Hadron Machines, Santiago de
Compostela, Spai
Predictions with Lattice QCD
In recent years, we used lattice QCD to calculate some quantities that were
unknown or poorly known. They are the dependence of the form factor in
semileptonic decay, the leptonic decay constants of the and
mesons, and the mass of the meson. In this paper, we summarize
these calculations, with emphasis on their (subsequent) confirmation by
measurements in , and collisions.Comment: 5 pages; update of hep-lat/0509169, with experimental confirmation of
form factors from Belle and fDs from BaBar; presented at SciDAC 2006 for the
Fermilab Lattice, MILC, and HPQCD Collaboration
Computational approach to the simulation of sapphire crystals growth by horizontal directed crystallization method
In this article we present an integrated approach to sapphire crystals growth simulation. Thermally induced stresses in sapphire crystals growing by horizontal directed crystallization are simulated by finite element method. The simulation results correspond to experimental observations. The results of the investigation allow to improve the process of crystal growth to obtain high quality large sapphire crystal. © Published under licence by IOP Publishing Ltd
A Study of the Pore Surface State of Porous TiNi-based Materials Obtained by SHS at Various Ignition Temperatures
Structural features of porous TiNi-based materials obtained by SHS at temperatures of synthesis beginning of400 Cand600 Chave been investigated. It is found that finely porous material with a porosity P=75 % was obtained at the temperature of400 C. A surface of pore walls contains a dendritic relief, oxycarbidenitride layer and a multitude of secondary phase particles. Phase and chemical composition of the material is non-uniform. SHS material obtained at the synthesis beginning temperature of600 °Cis characterized as a coarse-porosity one P=65 %. Nano- and micropores are practically absent. The oxycarbidenitride surface layer with a variable thickness is substantially free of secondary inclusions due to the more complete processes of alloy formation. This layer has an own substructure based on carbonitride and oxynitride layers
Проницаемость пористых сплавов на основе никелида титана с добавками титана, полученных методом диффузионного спекания
Выполнено исследование структурных особенностей пористых сплавов на основе никелида титана с различной концентрацией добавки Ti, полученных методом диффузионного спекания. Определены параметры макроструктуры порового пространства сплавов TiNi–Ti – коэффициенты пористости и проницаемости, средний размер пор и межпоровых перемычек. Увеличение концентрации добавок Ti ведет к уменьшению средних размеров пор и увеличению средних размеров межпоровых перемычек. Исследованы коэффициенты проницаемости пористых материалов, полученных методами диффузионного спекания и СВС. Установлено, что коэффициенты проницаемости образцов, полученных разными методами, существенно отличались несмотря на схожие коэффициенты пористости. Это может быть объяснено тем, что экспериментальные образцы, полученные разными методами, имеют отличающуюся структуру поровых каналов: СВС-материал имеет регулярную взаимосвязанную пористую структуру, а спеченный материал – менее взаимосвязанные поры в продольном направлении, что в совокупности с малым размером пор затрудняет течение жидкости в материале
Measurement of the lifetimes of B meson mass eigenstates
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 2004.Includes bibliographical references (p. 201-209).In this dissertation, we present the results of the average lifetime measurements in ..., ..., and ... decays, as well as the results of a time-dependent angular analysis of ... and ... decays. The time-dependent angular analysis of ... allows the extraction of separate lifetimes for the mass eigenstates, ... and ..., in the ... system. The two lifetimes are combined to extract the width difference, ..., between the two eigenstates. This quantity is extremely useful for over-constraining the Unitarity Triangle and thereby inferring if CP violation in the quark sector is entirely explained within the Standard Model. From ... of data collected by CDF up to February 13, 2004, we obtain a wealth of results, most importantly: ... Several of the results obtained here are currently the best of their kind, and in some cases they are unique measurements. We devote special attention to these, in particular ...by Konstantin Anikeev.Ph.D
Получение биосовместимых пористых сплавов на основе никелида титана методами СВС и спекания
В статье рассматривается проблема получения сплавов на основе никелида титана (TiNi). Значительное внимание уделяется производству пористых проницаемых сплавов на основе TiNi. Существуют различные способы получения сплавов на основе TiNi, но многие из них требуют дорогостоящего оборудования, а также имеют недостатки, такие как продолжительность синтеза и получение недостаточно чистого продукта. Сегодня для получения пористых материалов широко используются методы самораспространяющегося высокотемпературного синтеза (СВС) и спекания, основным преимуществом которого является возможность получения пористых материалов с регулируемыми характеристиками структуры и физико-механическими свойствами. Поэтому целью данной работы является определение параметров СВС и спекания
Features of Cells Integration on TiNi-based Porous Scaffold
Developing of standard population of cells — line fibroblasts 3T3 in porous structure of incubator having fixed composition, porousness and pore size distribution has been studied. The volume of scaffold space was shown to determine the potential cell division and its function. The characteristic integration of fibroblasts in porous incubators from TiNi-based alloy having different volumes was analyzed. The relation of colonization by cells and growth of tissues in porous samples from titanium nickel depending on depth of penetration is determined
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