2,705 research outputs found
Study of four-body decays in the perturbative QCD approach
In this work, we make a systematical study on the four-body decays in the perturbative QCD approach, where the
invariant mass spectra are dominated by the vector resonance and
the scalar resonance . We improve the Gengenbauer moments for the
longitudinal -wave two-pion distribution amplitudes (DAs) by fitting the
PQCD factorization formulas to measured branching ratios of three-body and
four-body decays. With the fitted Gegenbauer moments, we make predictions
for the branching ratios and direct asymmetries of four-body decays. We extract the branching ratios of two-body from the corresponding four-body decay modes and calculate the
relevant polarization fractions. We find that the is consistent with the previous theoretical predictions and
data. The leading-order PQCD calculations of the , and the are a bit lower than the experimental measurements, which should
be further examined. In addition, the "true" and "fake" triple-product
asymmetries (TPAs) in the decays are also
analyzed. The sizable averaged TPA of the color-suppressed decay is predicted for the first time, which deviates a lot
from the so-called "true" TPA due to the
large direct violation. A large "fake" TPA
of the decay is also found, which indicates the significance of
the final-state interactions. The predictions in this work can be tested by
LHCb and Belle-II experiments in the near future.Comment: 24 pages, 4 figures. Several new references are added. arXiv admin
note: text overlap with arXiv:2204.01092, arXiv:2107.1068
Saline and Alkaline tolerance of wetland plants — what are the most representative evaluation indicators?
The increasing discharge of wastewater containing inorganic salts, sometimes accompanied by high pH, has been a worldwide environmental problem. Constructed wetlands (CWs) are considered a viable technology for treating saline and/or alkaline wastewater provided that saline-alkaline tolerant plant species are selected and applied. The influence of both saline and alkaline stress on four wetland plant species during their seed germination, early growth, vegetative propagation and continued growth stages was evaluated by three experiments. Principal component analysis (PCA) was conducted for selecting representative indicators for evaluating the saline and alkaline tolerance of plants during vegetative propagation and plant growth stages. The saline and alkaline stress inhibited the vegetative propagation and plant growth of all tested plant species to varying degrees, therein the influences of saline-alkaline stress on plants were more marked than saline stress. The length of new roots, Na+ accumulation in plant tissue, Na+/K+ ratios in aerial tissue and the total dry biomass were selected as most representative indicators for evaluating the saline and alkaline tolerance of plants. Iris sibirica and Lythrum salicaria showed better saline and alkaline tolerance ability among tested species and could be grown in CWs for treating saline and/or alkaline wastewater
Measuring the boundary gapless state and criticality via disorder operator
The disorder operator is often designed to reveal the conformal field theory
(CFT) information in the quantum many-body system. By using large-scale quantum
Monte Carlo simulation, we study the scaling behavior of disorder operator on
the boundary in the two-dimensional Heisenberg model on the square-octagon
lattice with gapless topological edge state. In the Affleck-Kennedy-Lieb-Tasaki
(AKLT) phase, the disorder operator is shown to hold the perimeter scaling with
a logarithmic term associated with the Luttinger Liquid parameter K. This
effective Luttinger Liquid parameter K reflects the low energy physics and CFT
for (1+1)d boundary. At bulk critical point, the effective K is suppressed but
keep finite value, indicating the coupling between the gapless edge state and
bulk fluctuation. The logarithmic term numerically capture this coupling
picture, which reveals the (1+1)d SU(2)_1 CFT and (2+1)d O(3) CFT at boundary
criticality. Our work paves a new way to study the exotic boundary state and
boundary criticality.Comment: 8 Pages,7 figure
Electronic Structures of Graphene Layers on Metal Foil: Effect of Point Defects
Here we report a facile method to generate a high density of point defects in
graphene on metal foil and show how the point defects affect the electronic
structures of graphene layers. Our scanning tunneling microscopy (STM)
measurements, complemented by first principle calculations, reveal that the
point defects result in both the intervalley and intravalley scattering of
graphene. The Fermi velocity is reduced in the vicinity area of the defect due
to the enhanced scattering. Additionally, our analysis further points out that
periodic point defects can tailor the electronic properties of graphene by
introducing a significant bandgap, which opens an avenue towards all-graphene
electronics.Comment: 4 figure
Decouple knowledge from paramters for plug-and-play language modeling
Pre-trained language models(PLM) have made impressive results in various NLP
tasks. It has been revealed that one of the key factors to their success is the
parameters of these models implicitly learn all kinds of knowledge during
pre-training. However, encoding knowledge implicitly in the model parameters
has two fundamental drawbacks. First, the knowledge is neither editable nor
scalable once the model is trained, which is especially problematic in that
knowledge is consistently evolving. Second, it lacks interpretability and
prevents humans from understanding which knowledge PLM requires for a certain
problem. In this paper, we introduce PlugLM, a pre-training model with
differentiable plug-in memory(DPM). The key intuition is to decouple the
knowledge storage from model parameters with an editable and scalable key-value
memory and leverage knowledge in an explainable manner by knowledge retrieval
in the DPM. To justify this design choice, we conduct evaluations in three
settings including: (1) domain adaptation. PlugLM obtains 3.95 F1 improvements
across four domains on average without any in-domain pre-training. (2)
knowledge update. PlugLM could absorb new knowledge in a training-free way
after pre-training is done. (3) in-task knowledge learning. PlugLM could be
further improved by incorporating training samples into DPM with knowledge
prompting.Comment: ACL2023 Finding
Mass-induced sea level change in the northwestern North Pacific and its contribution to total sea level change
Author Posting. © American Geophysical Union, 2013. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 40 (2013): 3975–3980, doi:10.1002/grl.50748.Over the period 2003–2011, the Gravity Recovery and Climate Experiment (GRACE) satellite pair revealed a remarkable variability in mass-induced sea surface height (MSSH) in the northwestern North Pacific. A significant correlation is found between MSSH and observed total sea surface height (SSH), indicative of the importance of barotropic variability in this region. For the period 2003–2011, MSSH rose at a rate of 6.1 ± 0.7 mm/yr, which has a significant contribution to the SSH rise (8.3 ± 0.7 mm/yr). Analysis of the barotropic vorticity equation based on National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis product, GRACE, and altimetry data suggests that the MSSH signal is primarily caused by negative wind stress curl associated with an anomalous anticyclonic atmospheric circulation. Regression analysis indicates that trends in MSSH and surface wind are related to the Pacific Decadal Oscillation, whose index had a decreasing trend in the last decade.This work was supported by the National
Basic Research Program of China (2010CB950303 and 2012CB955603)
and the National Natural Science Foundation of China (41176023,
41276108, and 41006006). X.H.C. is also sponsored by “Youth Innovation
Promotion Association,” CAS (SQ201204, LTOZZ1202).2014-02-0
Multi-domain Recommendation with Embedding Disentangling and Domain Alignment
Multi-domain recommendation (MDR) aims to provide recommendations for
different domains (e.g., types of products) with overlapping users/items and is
common for platforms such as Amazon, Facebook, and LinkedIn that host multiple
services. Existing MDR models face two challenges: First, it is difficult to
disentangle knowledge that generalizes across domains (e.g., a user likes cheap
items) and knowledge specific to a single domain (e.g., a user likes blue
clothing but not blue cars). Second, they have limited ability to transfer
knowledge across domains with small overlaps. We propose a new MDR method named
EDDA with two key components, i.e., embedding disentangling recommender and
domain alignment, to tackle the two challenges respectively. In particular, the
embedding disentangling recommender separates both the model and embedding for
the inter-domain part and the intra-domain part, while most existing MDR
methods only focus on model-level disentangling. The domain alignment leverages
random walks from graph processing to identify similar user/item pairs from
different domains and encourages similar user/item pairs to have similar
embeddings, enhancing knowledge transfer. We compare EDDA with 12
state-of-the-art baselines on 3 real datasets. The results show that EDDA
consistently outperforms the baselines on all datasets and domains. All
datasets and codes are available at https://github.com/Stevenn9981/EDDA.Comment: Accepted by CIKM'23 as a Long pape
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