3,841 research outputs found
from the semileptonic decay and the properties of the meson distribution amplitude
The improved QCD light-cone sum rule (LCSR) provides an effective way to deal
with the heavy-to-light transition form factors (TFFs). Firstly, we adopt the
improved LCSR approach to deal with the TFF up to twist-4
accuracy. Due to the elimination of the most uncertain twist-3 contribution and
the large suppression of the twist-4 contribution, the obtained LCSR shall
provide us a good platform for testing the -meson leading-twist DA. For the
purpose, we suggest a new model for the -meson leading-twist DA
(), whose longitudinal behavior is dominantly determined by a
parameter . Moreover, we find its second Gegenbauer moment .
Varying within certain region, one can conveniently mimic the -meson DA
behavior suggested in the literature. Inversely, by comparing the estimations
with the experimental data on the -meson involved processes, one can get a
possible range for the parameter and a determined behavior for the
-meson DA. Secondly, we discuss the TFF at the maximum recoil
region and present a detailed comparison of it with the pQCD estimation and the
experimental measurements. Thirdly, by applying the LCSR on , we
study the CKM matrix element \Vcb together with its uncertainties by adopting
two types of processes, i.e. the -type and the -type.
It is noted that a smaller shows a better agreement with the
experimental value on \Vcb. For example, for the case of , we obtain
and , whose first (second)
uncertainty comes from the squared average of the mentioned theoretical
(experimental) uncertainties.Comment: 13 pages, 10 figures. Reference updated and discussion improved. To
be published in Nucl.Phys.
4-Methoxyanilinium hexafluorophosphate monohydrate
In the structure of the title compound, C7H10NO+·PF6
−·H2O, the protonated 4-methoxyanilinium cations and hexafluorophosphate anions are bridged by the water molecule via N—H⋯O and O—H⋯F hydrogen bonds. The resulting zigzag chains extend along the c axis. In addition, C—H⋯π interactions are observed in the crystal packing
The -meson longitudinal leading-twist distribution amplitude
In the present paper, we suggest a convenient model for the vector
-meson longitudinal leading-twist distribution amplitude
, whose distribution is controlled by a single parameter
. By choosing proper chiral current in the correlator, we obtain
new light-cone sum rules (LCSR) for the TFFs , and ,
in which the -order provides dominant
contributions. Then we make a detailed discussion on the
properties via those TFFs. A proper choice of can
make all the TFFs agree with the lattice QCD predictions. A prediction of
has also been presented by using the extrapolated TFFs, which
indicates that a larger leads to a larger . To
compare with the BABAR data on , the longitudinal leading-twist
DA prefers a doubly-humped behavior.Comment: 7 pages, 3 figures. Discussions improved and references updated. To
be published in Phys.Lett.
Nighttime Thermal Infrared Image Colorization with Feedback-based Object Appearance Learning
Stable imaging in adverse environments (e.g., total darkness) makes thermal
infrared (TIR) cameras a prevalent option for night scene perception. However,
the low contrast and lack of chromaticity of TIR images are detrimental to
human interpretation and subsequent deployment of RGB-based vision algorithms.
Therefore, it makes sense to colorize the nighttime TIR images by translating
them into the corresponding daytime color images (NTIR2DC). Despite the
impressive progress made in the NTIR2DC task, how to improve the translation
performance of small object classes is under-explored. To address this problem,
we propose a generative adversarial network incorporating feedback-based object
appearance learning (FoalGAN). Specifically, an occlusion-aware mixup module
and corresponding appearance consistency loss are proposed to reduce the
context dependence of object translation. As a representative example of small
objects in nighttime street scenes, we illustrate how to enhance the realism of
traffic light by designing a traffic light appearance loss. To further improve
the appearance learning of small objects, we devise a dual feedback learning
strategy to selectively adjust the learning frequency of different samples. In
addition, we provide pixel-level annotation for a subset of the Brno dataset,
which can facilitate the research of NTIR image understanding under multiple
weather conditions. Extensive experiments illustrate that the proposed FoalGAN
is not only effective for appearance learning of small objects, but also
outperforms other image translation methods in terms of semantic preservation
and edge consistency for the NTIR2DC task.Comment: 14 pages, 14 figures. arXiv admin note: text overlap with
arXiv:2208.0296
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