745,662 research outputs found
Supermembrane limit of Yang-Mills theory
We consider Yang-Mills theory with super translation group in eleven
auxiliary dimensions as the structure group. The gauge theory is defined on a
direct product manifold , where is a
three-dimensional Lorentzian manifold and is a circle. We show that in
the infrared limit, when the metric on is scaled down, the Yang-Mills
action supplemented by a Wess-Zumino-type term reduces to the action of an
M2-brane.Comment: 1+6 page
Phenomenological Applications of QCD Factorization to Semi-inclusive B Decays
We have systematically investigated the semi-inclusive B decays ,
which are manifestations of the quark decay , within a framework
inspired by QCD-improved factorization. These decays are theoretically clean
and have distinctive experimental signatures. We focus on a class of these that
do not require any form factor information and therefore may be especially
suitable for extracting information on the angles and of the
unitarity triangle. The strong phase coming from final-state rescattering due
to hard gluon exchange between the final states can induce large rate
asymmetries for tree-dominated color-suppressed modes
. The nonfactorizable hard spectator
interactions in the 3-body decay , though phase-space
suppressed, are extremely important for the tree-dominated modes
, and the
penguin-dominated mode . Our result for is in agreement with experiment. , , and are the most promising ones in searching for direct CP
violation: they have branching ratios of order and CP rate
asymmetries of order .Comment: 12 pages, talk given at International Conference on Flavor Physics,
Zhang-Jia-Jie City, Hunan, China, 31 May - 6 June, 200
PENGEMBANGAN DAN ANALISA KESERAGAMAN ALIRAN TEROWONGAN ANGIN TIPE TERBUKA SEBAGAI SARANA PENGUJIAN AERODINAMIKA
Terowongan angin sebagai sarana praktikum dan riset di bidang aerodinamika sangat penting keberadaannya, namun harganya yang mahal seringkali menjadi kendala utama di berbagai institusi pendidikan. Pengembangan terowongan angin dengan biaya murah namun memenuhi syarat sangat penting untuk dilakukan. Penelitian ini bertujuan untuk mengembangkan terowongan angin tipe terbuka dan menguji keseragaman aliran pada seksi uji sehingga layak untuk dipergunakan. Terowongan angin dibuat dari plat besi dengan tebal 1,4 mm, angin dihasilkan oleh fan aksial yang digerakkan dengan motor listrik dengan daya 1 HP. Pengujian dilakukan pada bebrapa kecepatan angin yang berbeda, variasi kecepatan diperoleh dengan mengubah putaran motor listrik menggunakan inverter. Hasil pengujian menunjukkan bahwa kecepatan terendah yang dicapai adalah 2 m/s dan tertinggi 5,8 m/s. Pada kecepatan 2 m/s variasi kecepatan pada seksi uji sekitar 0,1 m/s , dan pada kecepatan 5,8 m/s sekitar 0,1 hingga 0,3 m/s
Kata Kunci : terowongan angin, aerodinamika, open circuit wind tunne
Maximally Non-Abelian Vortices from Self-dual Yang--Mills Fields
A particular dimensional reduction of SU(2N) Yang--Mills theory on , with a Riemann surface, yields an
gauge theory on , with a matrix Higgs field. The SU(2N) self-dual
Yang--Mills equations reduce to Bogomolny equations for vortices on .
These equations are formally integrable if is the hyperbolic plane,
and we present a subclass of solutions.Comment: 11 page
New Physics in b --> s bar(s) s Decay
We perform a model-independent analysis of the data on branching ratios and
CP asymmetries of and modes. The present
data is encouraging to look for indirect evidences of physics beyond the
Standard Model. We investigate the parameter spaces for different possible
Lorentz structures of the new physics four-Fermi interaction. It is shown that
if one takes the data at confidence level, only one particular
Lorentz structure is allowed. Possible consequences for the system are
also discussed.Comment: 9 pages, 3 encapsulated figures, minor changes in the text,
conclusions unchanged, a few references added, version to appear in PL
Yang-Yang thermodynamics on an atom chip
We investigate the behavior of a weakly interacting nearly one-dimensional
(1D) trapped Bose gas at finite temperature. We perform in situ measurements of
spatial density profiles and show that they are very well described by a model
based on exact solutions obtained using the Yang-Yang thermodynamic formalism,
in a regime where other, approximate theoretical approaches fail. We use
Bose-gas focusing [Shvarchuck etal., Phys. Rev. Lett. 89, 270404 (2002)] to
probe the axial momentum distribution of the gas, and find good agreement with
the in situ results.Comment: extended introduction and conclusions, and minor changes throughout;
accepted for publication in Phys. Rev. Let
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