Searcharxiv⌕ Search

arXiv subjects

Yang Gao

Publications and source records attributed to Yang Gao.

At least 577 records · Page 32Linked to original sources

Entity-Agnostic Representation Learning for Parameter-Efficient Knowledge Graph Embedding

We propose an entity-agnostic representation learning method for handling the problem of inefficient parameter storage costs brought by embedding knowledge graphs. Conventional knowledge graph embedding methods map elements in a knowledge graph, including entities and relations, into continuous vector spaces by assigning them one or multiple specific embeddings (i.e., vector representations). Thus the number of embedding parameters increases linearly as the growth of knowledge graphs. In our proposed model, Entity-Agnostic Representation Learning (EARL), we only learn the embeddings for a small set of entities and refer to them as reserved entities. To obtain the embeddings for the full set of entities, we encode their distinguishable information from their connected relations, k-nearest reserved entities, and multi-hop neighbors. We learn universal and entity-agnostic encoders for transforming distinguishable information into entity embeddings. This approach allows our proposed EARL to have a static, efficient, and lower parameter count than conventional knowledge graph embedding methods. Experimental results show that EARL uses fewer parameters and performs better on link prediction tasks than baselines, reflecting its parameter efficiency.

cs.CL↗

Study of $e^+e^-\toγϕJ/ψ$ from $\sqrt{s}=4.600$ to $4.951$ GeV

Using data samples with an integrated luminosity of $6.4$~fb$^{-1}$ collected by the BESIII detector operating at the BEPCII storage ring, the process of $e^+e^-\toγϕJ/ψ$ is studied. The processes of $e^+e^-\toϕχ_{c1,c2}$, $χ_{c1,c2}\toγJ/ψ$ are observed with a significance of more than $10σ$. The $\sqrt{s}$-dependent cross section of $e^+e^- \to ϕχ_{c1,c2}$ is measured between 4.600 and 4.951~GeV, and evidence of a resonance structure is found for the first time in the $ϕχ_{c2}$ process. We also search for the processes of $e^+e^-\toγX(4140)$, $γX(4274)$ and $γX(4500)$ via the $γϕJ/ψ$ final state, but no obvious structures are found. The upper limits on the production cross section times the branching fraction for these processes at the 90% confidence level are reported.

hep-ex↗

Locating multiple magnetized anomalies by geomagnetic monitoring

The presence of magnetized anomalies in the shell of the Earth interrupts its geomagnetic field. We consider the inverse problem of identifying the anomalies by monitoring the variation of the geomagnetic field. Motivated by the theoretical unique identifiability result in [5], we develop a novel numerical scheme of locating multiple magnetized anomalies. In our study, we do not assume that the source that generates the geomagnetic field, and the medium configurations of the Earth's core and the magnetized anomalies are a-priori known. The core of the reconstruction scheme is a novel imaging functional whose quantitative behaviours can be used to identify the anomalies. Both rigorous analysis and extensive numerical experiments are provided to verify the effectiveness and promising features of the proposed reconstruction scheme.

math.NA↗

Search for hyperon $ΔS=ΔQ$ violating decay $Ξ^{0}\toΣ^{-}e^{+}ν_{e}$

Using a data sample of $(1.0087\pm0.0044)\times10^{10}$ $J/ψ$ decay events collected with the BESIII detector at the center-of-mass energy of $\sqrt{s}=3.097$ GeV, we present a search for the hyperon semileptonic decay $Ξ^{0}\toΣ^{-}e^{+}ν_{e}$ which violates the $ΔS=ΔQ$ rule. No significant signal is observed, and the upper limit on the branching fraction $\mathcal{B}(Ξ^{0}\toΣ^{-}e^{+}ν_{e})$ is determined to be $1.6\times10^{-4}$ at the 90% confidence level. This result improves the previous upper limit result by about one order of magnitude.

hep-ex↗

Search for hidden-charm tetraquark with strangeness in $e^{+}e^{-}\rightarrow K^+ D_{s}^{*-} D^{*0}+c.c.$

We report a search for a heavier partner of the recently observed $Z_{cs}(3985)^{-}$ state, denoted as $Z_{cs}^{\prime -}$, in the process $e^{+} e^{-}\rightarrow K^{+}D_{s}^{*-}D^{* 0}+c.c.$, based on $e^+e^-$ collision data collected at the center-of-mass energies of $\sqrt{s}=4.661$, 4.682 and 4.699 GeV with the BESIII detector. The $Z_{cs}^{\prime -}$ is of interest as it is expected to be a candidate for a hidden-charm and open-strange tetraquark. A partial-reconstruction technique is used to isolate $K^+$ recoil-mass spectra, which are probed for a potential contribution from $Z_{cs}^{\prime -}\to D_{s}^{*-}D^{* 0}$ ($c.c.$). We find an excess of $Z_{cs}^{\prime -}\rightarrow D_{s}^{*-}D^{*0}$ ($c.c.$) candidates with a significance of $2.1σ$, after considering systematic uncertainties, at a mass of $(4123.5\pm0.7_\mathrm{stat.}\pm4.7_\mathrm{syst.})\ \mathrm{MeV}/c^{2}$. As the data set is limited in size, the upper limits are evaluated at the 90\% confidence level on the product of the Born cross sections ($σ^{\mathrm{Born}}$) and the branching fraction ($\mathcal{B}$) of $Z_{cs}^{\prime-}\rightarrow D_{s}^{*-}D^{* 0}$, under different assumptions of the $Z_{cs}^{\prime -}$ mass from 4.120 to 4.140 MeV and of the width from 10 to 50 MeV at the three center-of-mass energies. The upper limits of $σ^{\rm Born}\cdot\mathcal{B}$ are found to be at the level of $\mathcal{O}(1)$ pb at each energy. Larger data samples are needed to confirm the $Z_{cs}^{\prime -}$ state and clarify its nature in the coming years.

hep-ex↗

Measurement of branching fraction of $D^{*+}_s\to D^+_s π^0$ relative to $D^{*+}_s\to D^+_s γ$

Based on 7.33 fb$^{-1}$ of $e^+e^-$ collision data taken at center-of-mass energies between 4.128 and 4.226 GeV with the BESIII detector, we measure the branching fraction of $D^{*+}_s\to D^+_sπ^0$ relative to that of $D^{*+}_s\to D^+_sγ$ to be $(6.16\pm 0.43\pm 0.19)\%$. The first uncertainty is statistical and the second one is systematic. By using the world average value of the branching fraction of $D^{*+}_s\to D^+_se^+e^-$, we determine the branching fractions of $D^{*+}_s\to D^+_sγ$ and $D^{*+}_s\to D^+_sπ^0$ to be $(93.57\pm0.44\pm0.19)\%$ and $(5.76\pm0.44\pm0.19)\%$, respectively.

hep-ex↗

First Observation of the Semileptonic Decay $Λ_c^+\rightarrow pK^- e^+ν_e$

Using $4.5~\mathrm{fb}^{-1}$ of $e^+e^-$ annihilation data samples collected at the center-of-mass energies ranging from 4.600~GeV to 4.699~GeV with the BESIII detector at the BEPCII collider, a first study of the semileptonic decays $Λ_c^+\rightarrow pK^-e^+ν_e$, $Λ_c^+\rightarrow Λ(1520) e^+ν_e$ and $Λ_c^+\rightarrow Λ(1405) e^+ν_e$ is performed. The $Λ_c^+\rightarrow pK^-e^+ν_e$ decay is observed with a significance of $8.2σ$ and the branching fraction is measured to be $\mathcal{B}(Λ_c^+\rightarrow pK^- e^+ν_e)=(0.88\pm0.17_{\rm stat.}\pm0.07_{\rm syst.})\times 10^{-3}$. We also report evidence of $Λ_c^+\rightarrow Λ(1520)e^+ν_e$ and $Λ_c^+\rightarrow Λ(1405)e^+ν_e$ with significances of $3.3σ$ and $3.2σ$, respectively, and measure $\mathcal B(Λ^+_c\rightarrow Λ(1520)e^+ν_e)=(1.02\pm0.52_{\rm stat.}\pm0.11_{\rm syst.})\times10^{-3}$ and $\mathcal B(Λ^+_c\rightarrow Λ(1405)[\rightarrow pK^-]e^+ν_e)=(0.42\pm0.19_{\rm stat.}\pm0.04_{\rm syst.})\times10^{-3}$. Combining these with the inclusive semileptonic $Λ_c^+$ branching fraction measured by BESIII, the relative fraction is determined to be $[\mathcal{B}(Λ_c^+\rightarrow pK^-e^+ν_e)/\mathcal{B}(Λ_c^+\rightarrow X e^+ν_e)]=(2.1\pm0.4_{\rm stat.}\pm0.2_{\rm syst.})\%$, which provides a clear confirmation that semileptonic $Λ_c^+$ decays are not saturated by the $Λ\ell^+ν_{\ell}$ final state.

hep-ex↗

Observation of the $J/ψ$ and $ψ(3686)$ decays into $ηΣ^{+}\barΣ^{-}$

The decays $J/ψ\toηΣ^{+}\barΣ{}^-$ and $ψ(3686)\toηΣ^{+}\barΣ{}^-$ are observed for the first time, using $(10087 \pm 44)\times 10^{6}$ $J/ψ$ and $(448.1 \pm 2.9)\times 10^{6}$ $ψ(3686)$ events collected with the BESIII detector at the BEPCII collider. We determine the branching fractions of these two decays to be ${\cal B}(J/ψ\toηΣ^{+}\barΣ{}^-)=(6.34 \pm 0.21 \pm 0.37)\times 10^{-5}$ and ${\cal B}(ψ(3686)\toηΣ^{+}\barΣ{}^-)=(9.59 \pm 2.37 \pm 0.61)\times 10^{-6}$, where the first uncertainties are statistical and the second are systematic. The ratio of these two branching fractions is determined to be $\frac{{\cal B}(ψ(3686)\toηΣ^{+}\barΣ{}^-)}{{\cal B}(J/ψ\toηΣ^{+}\barΣ{}^-)}=(15.1 \pm 3.8)\%$, which is in agreement with the "12\% rule."

hep-ex↗

PanoViT: Vision Transformer for Room Layout Estimation from a Single Panoramic Image

In this paper, we propose PanoViT, a panorama vision transformer to estimate the room layout from a single panoramic image. Compared to CNN models, our PanoViT is more proficient in learning global information from the panoramic image for the estimation of complex room layouts. Considering the difference between a perspective image and an equirectangular image, we design a novel recurrent position embedding and a patch sampling method for the processing of panoramic images. In addition to extracting global information, PanoViT also includes a frequency-domain edge enhancement module and a 3D loss to extract local geometric features in a panoramic image. Experimental results on several datasets demonstrate that our method outperforms state-of-the-art solutions in room layout prediction accuracy.

cs.CV↗

Observations of the Cabibbo-Suppressed decays $Λ_{c}^{+}\to nπ^{+}π^{0}$, $nπ^{+}π^{-}π^{+}$ and the Cabibbo-Favored decay $Λ_{c}^{+}\to nK^{-}π^{+}π^{+}$

Using electron-positron annihilation data samples corresponding to an integrated luminosity of 4.5 $\rm{{fb}^{-1}}$, collected by the BESIII detector in the energy region between $4600$ MeV and $4699$ MeV, we report the first observations of the Cabibbo-suppressed decays $Λ_c^+\to nπ^+π^0$, $Λ_c^+\to nπ^+π^-π^+$, and the Cabibbo-favored decay $Λ_c^+\to nK^-π^+π^+$ with statistical significances of $7.9σ$, $7.8σ$, and $>10σ$, respectively. The branching fractions of these decays are measured to be $\mathcal{B}(Λ_{c}^{+}\rightarrow nπ^{+}π^{0})=(0.64\pm0.09\pm0.02)\%$, $\mathcal{B}(Λ_{c}^{+}\rightarrow nπ^{+}π^{-}π^{+})=(0.45\pm0.07\pm0.03)\%$, and $\mathcal{B}(Λ_{c}^{+}\rightarrow nK^{-}π^{+}π^{+})=(1.90\pm0.08\pm0.09)\%$, where the first uncertainties are statistical and the second are systematic. We find that the branching fraction of the decay $Λ_{c}^{+}\rightarrow nπ^{+}π^{0}$ is about one order of magnitude higher than that of $Λ_{c}^{+}\rightarrow nπ^{+}$.

hep-ex↗

MutexMatch: Semi-Supervised Learning with Mutex-Based Consistency Regularization

The core issue in semi-supervised learning (SSL) lies in how to effectively leverage unlabeled data, whereas most existing methods tend to put a great emphasis on the utilization of high-confidence samples yet seldom fully explore the usage of low-confidence samples. In this paper, we aim to utilize low-confidence samples in a novel way with our proposed mutex-based consistency regularization, namely MutexMatch. Specifically, the high-confidence samples are required to exactly predict "what it is" by conventional True-Positive Classifier, while the low-confidence samples are employed to achieve a simpler goal -- to predict with ease "what it is not" by True-Negative Classifier. In this sense, we not only mitigate the pseudo-labeling errors but also make full use of the low-confidence unlabeled data by consistency of dissimilarity degree. MutexMatch achieves superior performance on multiple benchmark datasets, i.e., CIFAR-10, CIFAR-100, SVHN, STL-10, mini-ImageNet and Tiny-ImageNet. More importantly, our method further shows superiority when the amount of labeled data is scarce, e.g., 92.23% accuracy with only 20 labeled data on CIFAR-10. Our code and model weights have been released at https://github.com/NJUyued/MutexMatch4SSL.

cs.CV↗

Determination of U-spin breaking parameters with an amplitude analysis of the decay $D^0 \to K_{\rm L}^0π^+π^-$

We present a study of the resonant structure of the decay $D^0 \to K_{\rm L}^0π^+π^-$, using quantum-correlated $D^0\bar{D}^0$ data produced at $\sqrt{s}=3.773$ GeV. The data sample was collected by the BESIII experiment and corresponds to an integrated luminosity of $2.93$ fb$^{-1}$. This study is the first amplitude analysis of a decay mode involving a $K_{\rm L}^0$, which also results in the first measurement of the complex $\textit{U-spin breaking parameters}$ ($\hatρ$) related to various $\mathit{CP}$-eigenstate resonant modes through which the three-body decay proceeds. The moduli of the $\hatρ$ parameters have central values in a wide range from $0.4$ to $12.1$, which indicates substantial U-spin symmetry breaking. We present the fractional resonant contributions and average strong-phase parameters over regions of phase space for both $K_{\rm S}^0π^+π^-$ and $K_{\rm L}^0π^+π^-$ modes. We also report the ratio of the branching fractions between $K_{\rm L}^0π^+π^-$ and $K_{\rm S}^0π^+π^-$ decay modes and the $\mathit{CP}$-even fraction of the $K_{\rm L}^0π^+π^-$ state calculated using the U-spin breaking parameters.

hep-ex↗

Amplitude analysis of $D_s^{+} \rightarrow π^{+} π^{-} π^{+}$

Utilizing the data set corresponding to an integrated luminosity of $3.19$ fb$^{-1}$ collected by the BESIII detector at a center-of-mass energy of 4.178 GeV, we perform an amplitude analysis of the $D_s^+\toπ^+π^-π^+$ decay. The sample contains 13,797 candidates with a signal purity of $\sim$80%. The amplitude and phase of the contributing $ππ$ ${\cal S}$ wave are measured based on a quasi-model-independent approach, along with the amplitudes and phases of the ${\cal P}$ and ${\cal D}$ waves parametrized by Breit-Wigner models. The fit fractions of different intermediate decay channels are also reported.

hep-ex↗

Pre-Trained Image Encoder for Generalizable Visual Reinforcement Learning

Learning generalizable policies that can adapt to unseen environments remains challenging in visual Reinforcement Learning (RL). Existing approaches try to acquire a robust representation via diversifying the appearances of in-domain observations for better generalization. Limited by the specific observations of the environment, these methods ignore the possibility of exploring diverse real-world image datasets. In this paper, we investigate how a visual RL agent would benefit from the off-the-shelf visual representations. Surprisingly, we find that the early layers in an ImageNet pre-trained ResNet model could provide rather generalizable representations for visual RL. Hence, we propose Pre-trained Image Encoder for Generalizable visual reinforcement learning (PIE-G), a simple yet effective framework that can generalize to the unseen visual scenarios in a zero-shot manner. Extensive experiments are conducted on DMControl Generalization Benchmark, DMControl Manipulation Tasks, Drawer World, and CARLA to verify the effectiveness of PIE-G. Empirical evidence suggests PIE-G improves sample efficiency and significantly outperforms previous state-of-the-art methods in terms of generalization performance. In particular, PIE-G boasts a 55% generalization performance gain on average in the challenging video background setting. Project Page: https://sites.google.com/view/pie-g/home.

cs.LG↗

Optical Berry Curvature of Hinge State and Its Detection

We demonstrate that the topological hinge state can possess a nontrivial optical Berry curvature in the nonAbelian formulation of the Berry curvature. It can be readily probed by the circular photogalvanic effect (CPGE), with the light illuminating a specific hinge, and we refer to it as the hinge CPGE. As a concrete example, we calculate the hinge CPGE in ferromagnetic MnBi2nTe3n+1, and find that the hinge CPGE peak structure well reflects the optical Berry curvature of hinge states and the optical sum rule captures the optical Berry curvature between the hinge state and the ground state. Thus, the hinge CPGE provides a promising route towards the optical detection of the hinge state geometrical structure.

cond-mat.mes-hall↗

Search for the weak radiative decay $Λ_{c}^+\to Σ^+γ$ at BESIII

The Cabibbo-allowed weak radiative decay $Λ_{c}^+\to Σ^+γ$ has been searched for in a sample of $Λ_{c}^+\barΛ_{c}^-$ pairs produced in $e^+e^-$ annihilations, corresponding to an integrated luminosity of $4.5 \mathrm{fb}^{-1}$ collected with the BESIII detector at center-of-mass energies between 4.60 and 4.70 GeV. No excess of signal above background is observed, and we set an upper limit on the branching fraction of this decay to be ${\mathcal B}(Λ_{c}^+\to Σ^+γ)<4.4\times10^{-4}$ at a confidence level of 90\%, which is in agreement with Standard Model expectations.

hep-ex↗

Measurement of the Branching Fraction of the Singly Cabibbo-Suppressed Decay $Λ_{c}^{+}\toΛK^{+}$

We report a branching fraction measurement of the singly Cabibbo-suppressed decay $Λ_{c}^{+}\toΛK^{+}$ using a data sample collected with the BESIII detector at the BEPCII storage ring. The data span center-of-mass energies from 4.599 to 4.950 GeV and correspond to an integrated luminosity of 6.44 fb$^{-1}$. The branching fraction of $Λ_{c}^{+}\toΛK^{+}$ relative to that of the Cabibbo-favored decay $Λ_{c}^{+}\toΛπ^{+}$ is measured to be $\mathcal{R}=\frac{\mathcal{B}(Λ_{c}^{+}\toΛK^{+})}{\mathcal{B}(Λ_{c}^{+}\toΛπ^{+})}=(4.78\pm0.34\pm0.20)\%$. Combining with the world-average value of $\mathcal{B}(Λ_{c}^{+}\toΛπ^{+})$, we obtain $\mathcal{B}(Λ_c^+\toΛK^+)=(6.21\pm0.44\pm0.26\pm0.34)\times 10^{-4}$. Here the first uncertainties are statistical, the second systematic, and the third comes from the uncertainty of the $Λ_{c}^{+}\toΛπ^{+}$ branching fraction. This result, which is more precise than previous measurements, does not agree with theoretical predictions, and suggests that non-factorizable contributions have been under-estimated in current models.

hep-ex↗

Partial wave analysis of the charmed baryon hadronic decay $Λ_c^+\toΛπ^+π^0$

Based on $e^+e^-$ collision samples corresponding to an integrated luminosity of 4.4 $\mbox{fb$^{-1}$}$ collected with the BESIII detector at center-of-mass energies between $4.6\,\,\mathrm{GeV}$ and $4.7\,\,\mathrm{GeV}$, a partial wave analysis of the charmed baryon hadronic decay $Λ_c^+\toΛπ^+π^0$ is performed, and the decays $Λ_c^+\toΛρ(770)^{+}$ and $Λ_c^+\toΣ(1385)π$ are studied for the first time. Making use of the world-average branching fraction $\mathcal{B}(Λ_c^+\toΛπ^+π^0)$, their branching fractions are determined to be \begin{eqnarray*} \begin{aligned} \mathcal{B}(Λ_c^+\toΛρ(770)^+)=&(4.06\pm0.30\pm0.35\pm0.23)\times10^{-2},\\ \mathcal{B}(Λ_c^+\toΣ(1385)^+π^0)=&(5.86\pm0.49\pm0.52\pm0.35)\times10^{-3},\\ \mathcal{B}(Λ_c^+\toΣ(1385)^0π^+)=&(6.47\pm0.59\pm0.66\pm0.38)\times10^{-3},\\ \end{aligned} \end{eqnarray*} where the first uncertainties are statistical, the second are systematic, and the third are from the uncertainties of the branching fractions $\mathcal{B}(Λ_c^+\toΛπ^+π^0)$ and $\mathcal{B}(Σ(1385)\toΛπ)$. In addition, %according to amplitudes determined from the partial wave analysis, the decay asymmetry parameters are measured to be $α_{Λρ(770)^+}=-0.763\pm0.053\pm0.045$, $α_{Σ(1385)^{+}π^0}=-0.917\pm0.069\pm0.056$, and $α_{Σ(1385)^{0}π^+}=-0.789\pm0.098\pm0.056$.

hep-ex↗