4,337 research outputs found
Semi-inclusive decays of meson into a dark anti-baryon and baryons
Using the recently developed -Mesogenesis scenario, we studied the
semi-inclusive decays of meson into a dark anti-baryon plus any
possible states containing and quarks with unit baryon number.
The two types of effective Lagrangians proposed by the scenario are both
considered in the study. The semi-inclusive decay branching fractions of are calculated by the method of heavy quark expansion, where the
non-perturbative contributions from the matrix elements of dimension-5
operators are included. We obtained the branching fractions as functions of the
dark anti-baryon mass. Using the experimental upper limits of the branching
fractions, we presented the constraints of the coupling constants in the
-Mesogenesis scenario.Comment: 17 pages, 4 figures and 1 tabl
Anomalous dimensions for the interpolating currents of baryons
The anomalous dimensions for the interpolating currents of baryons are
indispensable inputs in a serious analysis of baryon QCD sum rules. However,
the results in the literature are vague. In view of this, in this work, we
investigate the one-loop anomalous dimensions for some interpolating currents
such as those of and proton. This work has more significance in
pedagogy.Comment: 5 pages, 1 figur
A novel method for searching the - mixing effect in the angular distribution analysis of a four-body decay
In this work, we raised a novel method for searching the
- mixing effect in an angular distribution
analysis of the decay, where the
mixing effect can be observed by the appearance of the resonant.
Armed with this angular distribution, the decay branching fraction and the
forward-backward asymmetry are predicted. We pointed out that the
forward-backward asymmetry, as a function of the invariant mass square of
and the - mixing angle
, can be used to distinguish the two resonants and
even provide a possibility to determine the exact mixing angle.Comment: 7 pages, 3 figure
Light baryon in three quark picture light front approach and its application: hyperon weak radiative decays
Motivated by recent experimental data on at BESIII, we
investigate a class of hyperon weak radiative decays. To estimate these
processes, in our research, we employ a new type of light-front quark model
with a three-quark picture for octet baryons. In the three-quark picture, with
the use of and spin symmetries, we present a general form of the
light front wave function for each octet baryon. By including contributions
from the penguin diagram and W exchange diagram, we perform a complete
calculation on the branching ratios () and the asymmetry parameter
() for hyperon weak radiative decay processes. Our results are helpful
for discovering additional hyperon weak radiative decay processes in
experimental facilities, and our research will promote the theoretical study of
baryons.Comment: 15 pages, 2 figures, 5 table
Ionic effect on combing of single DNA molecules and observation of their force-induced melting by fluorescence microscopy
Molecular combing is a powerful and simple method for aligning DNA molecules
onto a surface. Using this technique combined with fluorescence microscopy, we
observed that the length of lambda-DNA molecules was extended to about 1.6
times their contour length (unextended length, 16.2 micrometers) by the combing
method on hydrophobic polymethylmetacrylate (PMMA) coated surfaces. The effects
of sodium and magnesium ions and pH of the DNA solution were investigated.
Interestingly, we observed force-induced melting of single DNA molecules.Comment: 12 page
k-semistratifiable spaces and expansions of set-valued mappings
[EN] In this paper, the concept of k-upper semi-continuous set-valued mappings is introduced. Using this concept, we give characterizations of k-semistratifiable and k-MCM spaces, which answers a question posed by Xie and Yan.Yan, P.; Hu, X.; Xie, L. (2018). k-semistratifiable spaces and expansions of set-valued mappings. Applied General Topology. 19(1):145-153. doi:10.4995/agt.2018.7883SWORD14515319
When Prompt-based Incremental Learning Does Not Meet Strong Pretraining
Incremental learning aims to overcome catastrophic forgetting when learning
deep networks from sequential tasks. With impressive learning efficiency and
performance, prompt-based methods adopt a fixed backbone to sequential tasks by
learning task-specific prompts. However, existing prompt-based methods heavily
rely on strong pretraining (typically trained on ImageNet-21k), and we find
that their models could be trapped if the potential gap between the pretraining
task and unknown future tasks is large. In this work, we develop a learnable
Adaptive Prompt Generator (APG). The key is to unify the prompt retrieval and
prompt learning processes into a learnable prompt generator. Hence, the whole
prompting process can be optimized to reduce the negative effects of the gap
between tasks effectively. To make our APG avoid learning ineffective
knowledge, we maintain a knowledge pool to regularize APG with the feature
distribution of each class. Extensive experiments show that our method
significantly outperforms advanced methods in exemplar-free incremental
learning without (strong) pretraining. Besides, under strong retraining, our
method also has comparable performance to existing prompt-based models, showing
that our method can still benefit from pretraining. Codes can be found at
https://github.com/TOM-tym/APGComment: Accepted to ICCV 202
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