159 research outputs found
Measuring the Relative Strong Phase in and Decays
In a recently suggested method for measuring the weak phase in
decays, the relative strong phase in and decays (equivalently, in and \od \to K^{*+} K^-) plays a role. It is shown how a study of
the Dalitz plot in can yield information on this phase,
and the size of the data sample which would give a useful measurement is
estimated.Comment: 13 pages, latex, 5 figures, submitted to Phys. Rev. D. Appendix and
some text on additional resonant contributions adde
Image tag completion by local learning
The problem of tag completion is to learn the missing tags of an image. In
this paper, we propose to learn a tag scoring vector for each image by local
linear learning. A local linear function is used in the neighborhood of each
image to predict the tag scoring vectors of its neighboring images. We
construct a unified objective function for the learning of both tag scoring
vectors and local linear function parame- ters. In the objective, we impose the
learned tag scoring vectors to be consistent with the known associations to the
tags of each image, and also minimize the prediction error of each local linear
function, while reducing the complexity of each local function. The objective
function is optimized by an alternate optimization strategy and gradient
descent methods in an iterative algorithm. We compare the proposed algorithm
against different state-of-the-art tag completion methods, and the results show
its advantages
Efficient scheme for one-way quantum computing in thermal cavities
We propose a practical scheme for one-way quantum computing based on
efficient generation of 2D cluster state in thermal cavities. We achieve a
controlled-phase gate that is neither sensitive to cavity decay nor to thermal
field by adding a strong classical field to the two-level atoms. We show that a
2D cluster state can be generated directly by making every two atoms collide in
an array of cavities, with numerically calculated parameters and appropriate
operation sequence that can be easily achieved in practical Cavity QED
experiments. Based on a generated cluster state in Box configuration,
we then implement Grover's search algorithm for four database elements in a
very simple way as an example of one-way quantum computing.Comment: 6 pages, 3 figure
Possible Effects of Noncommutative Geometry on Weak CP Violation and Unitarity Triangles
Possible effects of noncommutative geometry on weak CP violation and
unitarity triangles are discussed by taking account of a simple version of the
momentum-dependent quark mixing matrix in the noncommutative standard model. In
particular, we calculate nine rephasing invariants of CP violation and
illustrate the noncommutative CP-violating effect in a couple of charged
D-meson decays. We also show how inner angles of the deformed unitarity
triangles are related to CP-violating asymmetries in some typical B_d and B_s
transitions into CP eigenstates. B-meson factories are expected to help probe
or constrain noncommutative geometry at low energies in the near future.Comment: RexTev 16 pages. Modifications made. References added. Accepted for
publication in Phys. Rev.
Widespread somatic L1 retrotransposition occurs early during gastrointestinal cancer evolution
Somatic L1 retrotransposition events have been shown to occur in epithelial cancers. Here, we attempted to determine how early somatic L1 insertions occurred during the development of gastrointestinal (GI) cancers. Using L1-targeted resequencing (L1-seq), we studied different stages of four colorectal cancers arising from colonic polyps, seven pancreatic carcinomas, as well as seven gastric cancers. Surprisingly, we found somatic L1 insertions not only in all cancer types and metastases but also in colonic adenomas, well-known cancer precursors. Some insertions were also present in low quantities in normal GI tissues, occasionally caught in the act of being clonally fixed in the adjacent tumors. Insertions in adenomas and cancers numbered in the hundreds, and many were present in multiple tumor sections, implying clonal distribution. Our results demonstrate that extensive somatic insertional mutagenesis occurs very early during the development of GI tumors, probably before dysplastic growth
Neutrino mixing matrices with relatively large and with texture one-zero
The recent T2K, MINOS and Double Chooz oscillation data hint a relatively
large , which can be accommodated by some general modification of
the Tribimaximal/Bimaximal/Democratic mixing matrices. Using such matrices we
analyze several Majorana mass matrices with texture one-zero and show whether
they satisfy normal or inverted mass hierarchy and phenomenologically viable or
not.Comment: 16 pages, 3 figures, minor modification in the text, version to
appear in EPJ
A White Paper on keV sterile neutrino Dark Matter
We present a comprehensive review of keV-scale sterile neutrino Dark Matter, collecting views and insights from all disciplines involved—cosmology, astrophysics, nuclear, and particle physics—in each case viewed from both theoretical and experimental/observational perspectives. After reviewing the role of active neutrinos in particle physics, astrophysics, and cosmology, we focus on sterile neutrinos in the context of the Dark Matter puzzle. Here, we first review the physics motivation for sterile neutrino Dark Matter, based on challenges and tensions in purely cold Dark Matter scenarios. We then round out the discussion by critically summarizing all known constraints on sterile neutrino Dark Matter arising from astrophysical observations, laboratory experiments, and theoretical considerations. In this context, we provide a balanced discourse on the possibly positive signal from X-ray observations. Another focus of the paper concerns the construction of particle physics models, aiming to explain how sterile neutrinos of keV-scale masses could arise in concrete settings beyond the Standard Model of elementary particle physics. The paper ends with an extensive review of current and future astrophysical and laboratory searches, highlighting new ideas and their experimental challenges, as well as future perspectives for the discovery of sterile neutrinos
Prompt K_short production in pp collisions at sqrt(s)=0.9 TeV
The production of K_short mesons in pp collisions at a centre-of-mass energy
of 0.9 TeV is studied with the LHCb detector at the Large Hadron Collider. The
luminosity of the analysed sample is determined using a novel technique,
involving measurements of the beam currents, sizes and positions, and is found
to be 6.8 +/- 1.0 microbarn^-1. The differential prompt K_short production
cross-section is measured as a function of the K_short transverse momentum and
rapidity in the region 0 < pT < 1.6 GeV/c and 2.5 < y < 4.0. The data are found
to be in reasonable agreement with previous measurements and generator
expectations.Comment: 6+18 pages, 6 figures, updated author lis
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