1,836 research outputs found
Excited Heavy Quarkonium Production at the LHC through -Boson Decays
Sizable amount of heavy-quarkonium events can be produced through -boson
decays at the LHC. Such channels will provide a suitable platform to study the
heavy-quarkonium properties. The "improved trace technology", which disposes
the amplitude at the amplitude-level, is helpful for deriving
compact analytical results for complex processes. As an important new
application, in addition to the production of the lower-level Fock states
and , we make a further study on the
production of higher-excited -quarkonium Fock states
, and . Here
stands for the -charmonium,
-quarkonium and -bottomonium respectively. We show
that sizable amount of events for those higher-excited states can also be
produced at the LHC. Therefore, we need to take them into consideration for a
sound estimation.Comment: 7 pages, 9 figures and 6 tables. Typo errors are corrected, more
discussions and two new figures have been adde
1-[3-(4-Methoxyphenyl)-6-methyl-1,6-dihydro-1,2,4,5-tetrazin-1-yl]propanone
In the title compound, C13H16N4O2, the central tetrazine ring adopts an unsymmetrical boat conformation with the two C atoms as flagpoles. This compound can be considered as having homoaromaticity
Coherent quantum effects through dispersive bosonic media
The coherent evolution of two atomic qubits mediated by a set of bosonic
field modes is investigated. By assuming a specific encoding of the quantum
states in the internal levels of the two atoms we show that entangling quantum
gates can be realised, with high fidelity, even when a large number of
mediating modes is involved. The effect of losses and imperfections on the
gates' operation is also considered in detail.Comment: 7 pages, 10 figure
(E)-1-[(2-Chloro-5-methylpyridin-3-yl)methylene]thiosemicarbazide
The title compound, C8H9ClN4S, which has potential insecticidal activity, was synthesized by the reaction of 2-chloro-5-methylnicotinaldehyde and thiosemicarbazide. In the crystal structure, the molecules are linked via intermolecular N—H⋯N, N—H⋯S and N—H⋯Cl hydrogen bonds, forming a three-dimensional network stacked down a
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Quantification of atherosclerotic plaque volume in coronary arteries by computed tomographic angiography in subjects with and without diabetes.
BackgroundDiabetes mellitus (DM) is considered a cardiovascular risk factor. The aim of this study was to analyze the prevalence and volume of coronary artery plaque in patients with diabetes mellitus (DM) vs. those without DM.MethodsThis study recruited consecutive patients who underwent coronary computed tomography (CT) angiography (CCTA) between October 2016 and November 2017. Personal information including conventional cardiovascular risk factors was collected. Plaque phenotypes were automatically calculated for volume of different component. The volume of different plaque was compared between DM patients and those without DM.ResultsAmong 6381 patients, 931 (14.59%) were diagnosed with DM. The prevalence of plaque in DM subjects was higher compared with nondiabetic group significantly (48.34% vs. 33.01%, χ = 81.84, P < 0.001). DM was a significant risk factor for the prevalence of plaque in a multivariate model (odds ratio [OR] = 1.465, 95% CI: 1.258-1.706, P < 0.001). The volume of total plaque and any plaque subtypes in the DM subjects was greater than those in nondiabetic patients significantly (P < 0.001).ConclusionThe coronary artery atherosclerotic plaques were significantly higher in diabetic patients than those in non-diabetic patients
Comparison Between Single Loading–Unloading Indentation and Continuous Stiffness Indentation
Experiments are performed on fused silica, Si, and duplex stainless steel to examine whether the CSM (continuous stiffness indentation) method will provide approximately the “same” results of contact modulus and indentation hardness as those measured from the quasi-static single loading–unloading indentation. The experimental results show that the elastic modulus measured by the CSM method is compatible with that by the quasi-static loading–unloading method for hard materials, while there exists a percentage difference of ∼21.3% between the smallest value and the largest vale of the measured indentation hardnesses from the CSM method for fused silica and a percentage difference of ∼15.3% between the hardnesses measured by the CSM method and the single indentation for duplex stainless steel. The large percentage difference suggests that the indentation hardness measured by the CSM method may not be compatible with that measured by the quasi-static loading–unloading method for hard materials. The finite element results reveal the percentage difference between the indentation hardness at the wave peak and that at the wave valley for the CSM method increases with the increase of the ratio of elastic modulus to yield stress
Heavy Quarkonium Production at LHC through Boson Decays
The production of the heavy -quarkonium, -quarkonium
and -quarkonium states (-quarkonium for short), via
the semi-inclusive decays, has been systematically studied within the
framework of the non-relativistic QCD. In addition to the two color-singlet
-wave states, we also discuss the production of the four color-singlet
-wave states and (with ) together with the two color-octet components
and . Improved
trace technology is adopted to derive the simplified analytic expressions at
the amplitude level, which shall be useful for dealing with the following
cascade decay channels. At the LHC with the luminosity and the center-of-mass energy TeV, sizable
heavy-quarkonium events can be produced through the boson decays, i.e.
, and
-wave charmonium events per year can be obtained; and
, and -wave
-quarkonium events per year can be obtained. Main theoretical
uncertainties have also been discussed. By adding the uncertainties caused by
the quark masses in quadrature, we obtain KeV, KeV, KeV and eV.Comment: 24 pages, 12 figures. References updated. To be published in
Phys.Rev. D. To match the published versio
An Empirical Study of Catastrophic Forgetting in Large Language Models During Continual Fine-tuning
Catastrophic forgetting (CF) is a phenomenon that occurs in machine learning
when a model forgets previously learned information as it learns new
information. As large language models (LLMs) have shown excellent performance,
it is interesting to uncover whether CF exists in the continual fine-tuning of
LLMs. In this study, we empirically evaluate the forgetting phenomenon in LLMs'
knowledge, from the perspectives of domain knowledge, reasoning, and reading
comprehension. The experiments demonstrate that catastrophic forgetting is
generally observed in LLMs ranging from 1b to 7b. Furthermore, as the scale
increases, the severity of forgetting also intensifies. Comparing the
decoder-only model BLOOMZ with the encoder-decoder model mT0, BLOOMZ suffers
less forgetting and maintains more knowledge. We also observe that LLMs can
mitigate language bias (e.g. gender bias) during continual fine-tuning.
Moreover, we find that ALPACA can maintain more knowledge and capacity compared
with LLAMA during the continual fine-tuning, which implies that general
instruction tuning can help mitigate the forgetting phenomenon of LLMs in the
further fine-tuning process
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