5,754 research outputs found
Interaction-induced first order correlation between spatially-separated 1D dipolar fermions
We calculate the ground-state properties of fermionic dipolar atoms or
molecules in a one-dimensional double-tube potential by using the Luttinger
liquid theory and the density matrix renormalization-group calculation. When
the external field is applied near a magic angle with respect to the
double-tube plane, the long-ranged dipolar interaction can generate a
spontaneous correlation between fermions in different tubes, even when the bare
intertube tunneling rate is negligibly small. Such interaction-induced
correlation strongly enhances the contrast of the interference fringes and
therefore can be easily observed in the standard time-of-flight experiment.Comment: Same as the published versio
Charmless Two-body decays In Soft-Collinear-Effective-Theory
We provide the analysis of charmless two-body decays under the
framework of the soft-collinear-effective-theory (SCET), where denotes a
light vector (pseudoscalar) meson. Besides the leading power contributions,
some power corrections (chiraly enhanced penguins) are also taken into account.
Using the current available and experimental data on
branching fractions and CP asymmetry variables, we find two kinds of solutions
in fit for the 16 non-perturbative inputs which are essential in the
87 and decay channels. Chiraly enhanced penguins can change
several charming penguins sizably, since they share the same topology. However,
most of the other non-perturbative inputs and predictions on branching ratios
and CP asymmetries are not changed too much. With the two sets of inputs, we
predict the branching fractions and CP asymmetries of other modes especially
decays. The agreements and differences with results in QCD
factorization and perturbative QCD approach are analyzed. We also study the
time-dependent CP asymmetries in channels with CP eigenstates in the final
states and some other channels such as and
. In the perturbative QCD approach, the
penguins in annihilation diagrams play an important role. Although
they have the same topology with charming penguins in SCET, there are many
differences between the two objects in weak phases, magnitudes, strong phases
and factorization properties.Comment: 34 pages, revtex, 2 figures, published at PR
Effectiveness of RSS feed item duplication detection using word matching
Users of feed aggregators know that duplicated articles are found occasionally on the feeds they subscribe to. It can be time consuming to read all articles and stumble upon duplicated items they have already read. Our work here is to determine the effectiveness of using basic word matching to remove duplicated items and only show the most relevant item, thus saving readers’ time. The method described in this paper to remove duplicates involves word matching heuristics with an appropriate matching percentage. The duplicated feeds are then ranked to only display the highest ranked article. Ranking is done using the number of search items found on the titles of the news feeds where the highest number returned will be considered the highest ranked article. Using Malaysian online news feeds, our method found that with a matching percentage of 40%, our method will be able to minimize duplicates effectively with minimal errors. We did further empirical studies using 9 technology blog feeds over a longer period to provide us with a better averaging results. The matching percentage obtained is also within the same quantum. The method described here has a low overhead in terms of processing for the duplicates and with careful selection of matching percentage, the system will effectively remove the majority of duplicate
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