20,092,594 research outputs found
Precision Measurement of the Mass Difference
We have measured the vector-pseudoscalar mass splitting , significantly more precise than the previous
world average. We minimize the systematic errors by also measuring the
vector-pseudoscalar mass difference using the radiative
decay , obtaining
. This is
then combined with our previous high-precision measurement of
, which used the decay . We also
measure the mass difference MeV, using the
decay modes of the and mesons.Comment: 18 pages uuencoded compressed postscript (process with uudecode then
gunzip). hardcopies with figures can be obtained by sending mail to:
[email protected]
D-branes from M-branes
The 2-brane and 4-brane solutions of ten dimensional IIA supergravity have a
dual interpretation as Dirichlet-branes, or `D-branes', of type IIA superstring
theory and as `M-branes' of an -compactified eleven dimensional
supermembrane theory, or M-theory. This eleven-dimensional connection is used
to determine the ten-dimensional Lorentz covariant worldvolume action for the
Dirichlet super 2-brane, and its coupling to background spacetime fields. It is
further used to show that the 2-brane can carry the Ramond-Ramond charge of the
Dirichlet 0-brane as a topological charge, and an interpretation of the 2-brane
as a 0-brane condensate is suggested. Similar results are found for the
Dirichlet 4-brane via its interpretation as a double-dimensional reduction of
the eleven-dimensional fivebrane. It is suggested that the latter be
interpreted as a D-brane of an open eleven-dimensional supermembrane.Comment: Version to appear in Physics Letters B. Incorporates minor revisions
to previous revised version. 16 p
Equitable -edge designs
The paper addresses design of experiments for classifying the input factors
of a multi-variate function into negligible, linear and other
(non-linear/interaction) factors. We give constructive procedures for
completing the definition of the clustered designs proposed Morris 1991, that
become defined for arbitrary number of input factors and desired clusters'
multiplicity. Our work is based on a representation of subgraphs of the
hyper-cube by polynomials that allows the formal verification of the designs'
properties. Ability to generate these designs in a systematic manner opens new
perspectives for the characterisation of the behaviour of the function's
derivatives over the input space that may offer increased discrimination
Resolutions of ideals of fat points with support in a hyperplane
Our results concern minimal graded free resolutions of fat point ideals for
points in a hyperplane. Suppose, for example, that I(m,d) is the ideal defining
r given points of multiplicity m in the projective space P^d. Assume that the
given points lie in a hyperplane P^{d-1} in P^d, and that the ground field k is
algebraically closed of characteristic 0. We give an explicit minimal graded
free resolution of I(m,d) in k[P^d] in terms of the minimal graded free
resolutions of the ideals I(j,d-1) in k[P^{d-1}] with j < m+1. As a corollary,
we give the following formula for the Poincare polynomial P_{m,d} of I(m,d) in
terms of the Poincare polynomials P_{j,d-1} of I(j,d-1): P_{m,d} = (1 +
XT)(\Sigma_{0<j\le m} T^{m-j}(P_{j,d-1} - 1)) + 1 + XT^m.Comment: 10 pages; to appear in Proc. Amer. Math. Soc.; some expositional
changes; added a reference to paper of Geramita, Migliore and Sabourin
(math.AC/0411445
Эволюция интерпретации термина "рекламное издание" в Беларуси и России
Статья посвящена установлению четкого и емкого определения термина «рекламное издание» в Беларуси и России. Проанализировано 36 нормативных, научных, практических, учебных, справочных изданий, выпущенных с 1890 по 2015 г. Описана эволюция взглядов на интерпретацию понятий «реклама», «рекламное издание» в белорусских и российских источниках. Выделены основные подходы к определению термина «рекламное издание»: использующегося в официальных и нормативных источниках, базирующегося на исследованиях А. Э. Мильчина. Установлена максимально полная дефиниция термина «рекламное издание» в нормативно-законодательной, научно-исследовательской, профессиональной, общественной среде в Беларуси и России, выявлены сходства (рекламным изданием может считаться издание, зарегистрированное в качестве специализированного для размещения (распространения) рекламы и содержащее рекламные материалы, цель которых — создание спроса на объекты рекламирования, информирование о них, форма подачи рекламных материалов — привлекающая внимание, краткая, легко запоминающаяся, расположение рекламных материалов — в зависимости от концепции издания) и отличия (сводятся к процентному объему рекламных материалов в одном выпуске издания. В Республике Беларусь содержание рекламных материалов для зарегистрированных государственных рекламных изданий может составлять 25% и более, для иных периодических изданий — 30% и более объема номера. В Российской Федерации объем рекламных материалов в зарегистрированных рекламных периодических печатных изданиях может составлять 40% и более объема одного номера. Издания, не зарегистрированные в качестве рекламных, не могут превышать указанный объем рекламных сообщений
The smallest sets of points not determined by their X-rays
Let be an -point set in with
and . A (discrete) X-ray of
in direction gives the number of points of on each line parallel to
. We define as the minimum number for which
there exist directions (pairwise linearly independent and
spanning ) such that two -point sets in exist
that have the same X-rays in these directions. The bound
has been observed many times in the
literature. In this note we show
for . For the
cases and , , this
represents the first upper bound on that is polynomial
in . As a corollary we derive bounds on the sizes of solutions to both the
classical and two-dimensional Prouhet-Tarry-Escott problem. Additionally, we
establish lower bounds on that enable us to prove a
strengthened version of R\'enyi's theorem for points in
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