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Yang Gao

Publications and source records attributed to Yang Gao.

At least 325 records · Page 18Linked to original sources
arXiv2024

CItruS: Chunked Instruction-aware State Eviction for Long Sequence Modeling

Long sequence modeling has gained broad interest as large language models (LLMs) continue to advance. Recent research has identified that a large portion of hidden states within the key-value caches of Transformer models can be discarded (also termed evicted) without affecting the perplexity performance in generating long sequences. However, we show that these methods, despite preserving perplexity performance, often drop information that is important for solving downstream tasks, a problem which we call information neglect. To address this issue, we introduce Chunked Instruction-aware State Eviction (CItruS), a novel modeling technique that integrates the attention preferences useful for a downstream task into the eviction process of hidden states. In addition, we design a method for chunked sequence processing to further improve efficiency. Our training-free method exhibits superior performance on long sequence comprehension and retrieval tasks over several strong baselines under the same memory budget, while preserving language modeling perplexity. The code and data have been released at https://github.com/ybai-nlp/CItruS.

cs.CL↗
arXiv2024

Observation of an axial-vector state in the study of $ψ(3686) \to ϕηη'$ decay

Using (2712.4 $\pm$ 14.3)$\times 10^{6}$ $ψ(3686)$ events collected with the BESIII detector at BEPCII, a partial wave analysis of the decay $ψ(3686) \to ϕηη' $ is performed with the covariant tensor approach. An axial-vector state with a mass near 2.3 $\rm GeV/c^2$ is observed for the first time. Its mass and width are measured to be 2316 $\pm 9_{\mathrm{stat}} \pm 30_{\mathrm{syst}}\,\rm MeV/c^2$ and 89 $\pm 15_{\mathrm{stat}} \pm 26_{\mathrm{syst}}\,\rm MeV$, respectively. The product branching fractions of $\mathcal{B}(ψ(3686) \to X(2300) η') \mathcal{B}(X(2300)\to ϕη)$ and $\mathcal{B}(ψ(3686) \to X(2300) η)\mathcal{B}(X(2300)\to ϕη')$ are determined to be (4.8 $\pm 1.3_{\mathrm{stat}} \pm 0.7_{\mathrm{syst}})\times 10^{-6}$ and (2.2 $\pm 0.7_{\mathrm{stat}} \pm 0.7_{\mathrm{syst}})\times 10^{-6}$, respectively. The branching fraction $\mathcal{B}(ψ(3686) \to ϕηη')$ is measured for the first time to be (3.14$\pm0.17_{\mathrm{stat}}\pm0.24_{\mathrm{syst}})\times10^{-5}$. The first uncertainties are statistical and the second are systematic.

hep-ex↗
arXiv2024

Constraining the Presence of Companion Planets in Hot Jupiter Planetary System Using TTV Observation from TESS

The presence of another planetary companion in a transiting exoplanet system can impact its transit light curve, leading to sinusoidal transit timing variations (TTV). By utilizing both $χ^2$ and RMS analysis, we have combined the TESS observation data with an N-body simulation to investigate the existence of an additional planet in the system and put a limit on its mass. We have developed CMAT, an efficient and user-friendly tool for fitting transit light curves and calculating TTV with a theoretical period, based on which we can give a limit on its hidden companion's mass. We use 260 hot Jupiter systems from the complete TESS data set to demonstrate the use of CMAT. Our findings indicate that, for most systems, the upper mass limit of a companion planet can be restricted to several Jupiter masses. This constraint becomes stronger near resonance orbits, such as the 1:2, 2:1, 3:1, and 4:1 mean motion resonance, where the limit is reduced to several Earth masses. These findings align with previous studies suggesting that a lack of companion planets with resonance in hot Jupiter systems could potentially support the high eccentricity migration theory. Additionally, we observed that the choice between $χ^2$ or {root mean square (RMS)} method does not significantly affect the upper limit on companion mass; however, $χ^2$ analysis may result in weaker restrictions but is statistically more robust compared to RMS analysis in most cases.

astro-ph.EP↗
arXiv2024

Leveraging Locality to Boost Sample Efficiency in Robotic Manipulation

Given the high cost of collecting robotic data in the real world, sample efficiency is a consistently compelling pursuit in robotics. In this paper, we introduce SGRv2, an imitation learning framework that enhances sample efficiency through improved visual and action representations. Central to the design of SGRv2 is the incorporation of a critical inductive bias-action locality, which posits that robot's actions are predominantly influenced by the target object and its interactions with the local environment. Extensive experiments in both simulated and real-world settings demonstrate that action locality is essential for boosting sample efficiency. SGRv2 excels in RLBench tasks with keyframe control using merely 5 demonstrations and surpasses the RVT baseline in 23 of 26 tasks. Furthermore, when evaluated on ManiSkill2 and MimicGen using dense control, SGRv2's success rate is 2.54 times that of SGR. In real-world environments, with only eight demonstrations, SGRv2 can perform a variety of tasks at a markedly higher success rate compared to baseline models. Project website: http://sgrv2-robot.github.io

cs.RO↗
arXiv2024

Search for $D^0\to K^-ηe^+ν_e$, $D^+\to K_S^0 ηe^+ν_e$ and $D^+\to ηηe^+ν_e$ decays

By analyzing $e^+e^-$ annihilation data corresponding to an integrated luminosity of 7.93 fb$^{-1}$, collected at the center-of-mass energy of 3.773 GeV with the BESIII detector, we search for the semileptonic decays $D^0\to K^-ηe^+ν_e$, $D^+\to K_S^0 ηe^+ν_e$ and $D^+\to ηηe^+ν_e$ for the first time. We present evidence for $D^0\to K^-ηe^+ν_e$ with a significance of $3.3σ$. The branching fraction of $D^0\to K^-ηe^+ν_e$ is measured to be $(0.84_{-0.34}^{+0.29}\pm0.22)\times 10^{-4}$. Here, the first uncertainties are statistical and the second ones are systematic. No significant signals are observed for the decays $D^+\to K_S^0 ηe^+ν_e$ and $D^+\to ηηe^+ν_e$ and we set the upper limits on their branching fractions.

hep-ex↗
arXiv2024

General Flow as Foundation Affordance for Scalable Robot Learning

We address the challenge of acquiring real-world manipulation skills with a scalable framework. We hold the belief that identifying an appropriate prediction target capable of leveraging large-scale datasets is crucial for achieving efficient and universal learning. Therefore, we propose to utilize 3D flow, which represents the future trajectories of 3D points on objects of interest, as an ideal prediction target. To exploit scalable data resources, we turn our attention to human videos. We develop, for the first time, a language-conditioned 3D flow prediction model directly from large-scale RGBD human video datasets. Our predicted flow offers actionable guidance, thus facilitating zero-shot skill transfer in real-world scenarios. We deploy our method with a policy based on closed-loop flow prediction. Remarkably, without any in-domain finetuning, our method achieves an impressive 81\% success rate in zero-shot human-to-robot skill transfer, covering 18 tasks in 6 scenes. Our framework features the following benefits: (1) scalability: leveraging cross-embodiment data resources; (2) wide application: multiple object categories, including rigid, articulated, and soft bodies; (3) stable skill transfer: providing actionable guidance with a small inference domain-gap. Code, data, and supplementary materials are available https://general-flow.github.io

cs.RO↗
arXiv2024

Search for $X(3872)\toπ^0π^0χ_{c1,2}$

Using 10.1 fb$^{-1}$ of $e^+e^-$ collision data collected by the BESIII detector with center-of-mass energies between 4.15 GeV and 4.30 GeV, we search for the decays $X(3872)\toπ^0π^0χ_{c1,2}$, where the $X(3872)$ is produced in $e^+e^-\toγX(3872)$. No evidence above $3σ$ is found for either decay. Upper limits at the $90\%$ C.L. on the branching fractions of $X(3872)\toπ^0π^0χ_{c1,2}$ normalized to the branching fraction of $X(3872)\toπ^+π^-J/ψ$ are set to be $\mathcal{B}(X(3872)\toπ^0π^0χ_{c1})/\mathcal{B}(X(3872)\toπ^+π^-J/ψ) < 1.1$ and $\mathcal{B}(X(3872)\toπ^0π^0χ_{c2})/\mathcal{B}(X(3872)\toπ^+π^-J/ψ) < 0.5$, taking into account both statistical and systematic uncertainties.

hep-ex↗
arXiv2024

EfficientZero V2: Mastering Discrete and Continuous Control with Limited Data

Sample efficiency remains a crucial challenge in applying Reinforcement Learning (RL) to real-world tasks. While recent algorithms have made significant strides in improving sample efficiency, none have achieved consistently superior performance across diverse domains. In this paper, we introduce EfficientZero V2, a general framework designed for sample-efficient RL algorithms. We have expanded the performance of EfficientZero to multiple domains, encompassing both continuous and discrete actions, as well as visual and low-dimensional inputs. With a series of improvements we propose, EfficientZero V2 outperforms the current state-of-the-art (SOTA) by a significant margin in diverse tasks under the limited data setting. EfficientZero V2 exhibits a notable advancement over the prevailing general algorithm, DreamerV3, achieving superior outcomes in 50 of 66 evaluated tasks across diverse benchmarks, such as Atari 100k, Proprio Control, and Vision Control.

cs.LG↗
arXiv2024

Search for the radiative transition $χ_{c1}(3872)\toγψ_2(3823)$

Using 9.0 $\rm fb^{-1}$ of $e^+e^-$ collision data collected at center-of-mass energies from 4.178 to 4.278 GeV with the BESIII detector at the BEPCII collider, we perform the first search for the radiative transition $χ_{c1}(3872)\toγψ_2(3823)$. No $χ_{c1}(3872)\toγψ_2(3823)$ signal is observed. The upper limit on the ratio of branching fractions $\mathcal{B}(χ_{c1}(3872)\toγψ_2(3823), ψ_2(3823)\toγχ_{c1})/\mathcal{B}(χ_{c1}(3872)\toπ^+π^- J/ψ)$ is set as 0.075 at the 90\% confidence level. Our result contradicts theoretical predictions under the assumption that the $χ_{c1}(3872)$ is the pure charmonium state $χ_{c1}(2P)$.

hep-ex↗
arXiv2024

Study of $D^{+} \to K_{S}^{0}K^{*}(892)^{+}$ in $D^{+} \to K_{S}^{0} K_{S}^{0} π^{+}$

Using a data sample of $e^+e^-$ collisions corresponding to an integrated luminosity of 7.93 $\rm fb^{-1}$ collected with the BESIII detector at the center-of-mass energy 3.773~GeV, we perform the first amplitude analysis of the decay $D^{+} \to K_{S}^{0} K_{S}^{0} π^{+}$. The absolute branching fraction of $D^{+} \to K_{S}^{0}K_{S}^{0} π^{+}$ is measured to be $(2.97 \pm 0.09_{\rm stat.} \pm 0.05_{\rm syst.})\times10^{-3}$. The dominant intermediate process is $D^{+} \to K_{S}^{0}K^{*}(892)^{+}$, whose branching fraction is determined to be $(8.72 \pm 0.28_{\rm stat.} \pm 0.15_{\rm syst.}) \times 10^{-3}$, including all the $K^*(892)^+$ decays.

hep-ex↗
arXiv2024

Search for $C$-even states decaying to $D_{s}^{\pm}D_{s}^{*\mp}$ with masses between $4.08$ and $4.32~\mathrm{GeV}/c^{2}$

Six $C$-even states, denoted as $X$, with quantum numbers $J^{PC}=0^{-+}$, $1^{\pm+}$, or $2^{\pm+}$, are searched for via the $e^+e^-\toγD_{s}^{\pm}D_{s}^{*\mp}$ process using $(1667.39\pm8.84)~\mathrm{pb}^{-1}$ of $e^+e^-$ collision data collected with the BESIII detector operating at the BEPCII storage ring at center-of-mass energy of $\sqrt{s}=(4681.92\pm0.30)~\mathrm{MeV}$. No statistically significant signal is observed in the mass range from $4.08$ to $4.32~\mathrm{GeV}/c^{2}$. The upper limits of $σ[e^+e^- \to γX] \cdot \mathcal{B}[X \to D_{s}^{\pm} D_{s}^{*\mp}]$ at a $90\%$ confidence level are determined.

hep-ex↗
arXiv2024

Precise Measurement of Born Cross Sections for $e^+e^-\to D\bar{D}$ at $\sqrt{s} = 3.80-4.95$ GeV

Using data samples collected with the BESIII detector at the BEPCII collider at center-of-mass energies ranging from 3.80 to 4.95 GeV, corresponding to an integrated luminosity of 20 fb$^{-1}$, a measurement of Born cross sections for the $e^+e^-\to D^{0}\bar{D}^{0}$ and $D^{+}D^{-}$ processes is presented with unprecedented precision. Many clear peaks in the line shape of $e^+e^-\to D^{0}\bar{D}^{0}$ and $D^{+}D^{-}$ around the mass range of $G(3900)$, $ψ(4040)$, $ψ(4160)$, $Y(4260)$, and $ψ(4415)$, etc., are foreseen. These results offer crucial experimental insights into the nature of hadron production in the open-charm region.

hep-ex↗
arXiv2024

DexCatch: Learning to Catch Arbitrary Objects with Dexterous Hands

Achieving human-like dexterous manipulation remains a crucial area of research in robotics. Current research focuses on improving the success rate of pick-and-place tasks. Compared with pick-and-place, throwing-catching behavior has the potential to increase the speed of transporting objects to their destination. However, dynamic dexterous manipulation poses a major challenge for stable control due to a large number of dynamic contacts. In this paper, we propose a Learning-based framework for Throwing-Catching tasks using dexterous hands (LTC). Our method, LTC, achieves a 73\% success rate across 45 scenarios (diverse hand poses and objects), and the learned policies demonstrate strong zero-shot transfer performance on unseen objects. Additionally, in tasks where the object in hand faces sideways, an extremely unstable scenario due to the lack of support from the palm, all baselines fail, while our method still achieves a success rate of over 60\%.

cs.RO↗
arXiv2024

Multipolar Anisotropy in Anomalous Hall Effect from Spin-Group Symmetry Breaking

Traditional view of the anomalous Hall effect~(AHE) in ferromagnets is that it arises from the magnetization perpendicular to the measurement plane and that there is a linear dependence on the latter. Underlying such a view is the thinking that the AHE is a time-reversal symmetry breaking phenomenon and can therefore be treated in terms of a power series in the magnetic order. However, this view is squarely challenged by a number of experiments recently, urging for a thorough theoretical investigation on the fundamental level. We find that for strong magnets, it is more appropriate and fruitful to regard the AHE as a spin-group symmetry breaking phenomenon where the critical parameter is the spin-orbit interaction strength, which involves a much smaller energy scale. In ferromagnets, the spin-orbit coupling breaks the $\infty 2^\prime$ spin rotation symmetry, and the key to characterizing such symmetry breaking is the identification of spin-orbit vectors which transform regularly under spin group operations. Born out of our framework is a rich multi-polar relationship between the anomalous Hall conductivity and the magnetization direction, with each pole being expanded progressively in powers of the spin-orbit coupling strength. For the leading order contribution, i.e., the dipole, its isotropic part corresponds to the traditional view, and its anisotropic part can lead to the in-plane AHE where the magnetization lies within the measurement plane. Beyond the dipolar one, the octupolar structure offers the leading order source of nonlinearity and hence introduces unique anisotropy where the dipolar structure cannot. The dipolar and octupolar structure offers a unified explanation for the in-plane AHE recently observed in various ferromagnets, and our comprehensive analysis further extends the candidate material systems.

cond-mat.mtrl-sci↗
arXiv2024

Measurements of $K_S^0$-$K_L^0$ asymmetries in the decays $Λ_c^+ \to pK_{L,S}^0$, $pK_{L,S}^0π^+π^-$ and $pK_{L,S}^0π^0$

Using $e^+e^-$ annihilation data sets corresponding to an integrated luminosity of 4.5 $\text{fb}^{-1}$, collected with the BESIII detector at center-of-mass energies between 4.600 and 4.699 GeV, we report the first measurements of the absolute branching fractions $\mathcal{B}(Λ_c^+\to pK_{L}^{0})=(1.67 \pm 0.06 \pm 0. 04)\%$, $\mathcal{B}(Λ_c^+\to pK_{L}^{0}π^+π^-)=(1.69 \pm 0.10 \pm 0.05)\%$, and $\mathcal{B}(Λ_c^+\to pK_{L}^{0}π^0)=(2.02 \pm 0.13 \pm 0.05)\%$, where the first uncertainties are statistical and the second systematic. Combining with the known branching fractions of $Λ_c^+ \to pK_{S}^{0}$, $Λ_c^+ \to pK_{S}^{0}π^+π^-$, and $Λ_c^+ \to pK_{S}^{0}π^0$, we present the first measurements of the $K_{S}^{0}$-$K_{L}^{0}$ asymmetries $R(Λ_c^+, K_{S,L}^0X) = \frac{\mathcal{B}(Λ_c^+ \to K_{S}^{0} X) - \mathcal{B}(Λ_c^+ \to K_{L}^{0} X)}{\mathcal{B}(Λ_c^+ \to K_{S}^{0} X) + \mathcal{B}(Λ_c^+ \to K_{L}^{0} X)}$ in charmed baryon decays: $R(Λ_c^+, pK_{S,L}^0) = -0.025 \pm 0.031$, $R(Λ_c^+, pK_{S,L}^0π^+π^-) = -0.027 \pm 0.048$, and $R(Λ_c^+, pK_{S,L}^0π^0) =-0.015 \pm 0.046$. No significant asymmetries within the uncertainties are observed.

hep-ex↗
arXiv2024

Search for $e^{+}e^{-}\toη'ψ(2S)$ at center-of-mass energies from 4.66 to 4.95 GeV

Using data samples with an integrated luminosity of $4.67~\mathrm{fb}^{-1}$ collected by the BESIII detector operating at the BEPCII collider, we search for the process $e^+e^- \rightarrow η' ψ(2S)$ at center-of-mass energies from $4.66$ to $4.95~\mathrm{GeV}$. No significant signal is observed, and upper limits for the Born cross sections $σ^B(e^+e^-\rightarrowη'ψ(2S))$ at the 90\% confidence level are determined.

hep-ex↗
arXiv2024

Best-of-Venom: Attacking RLHF by Injecting Poisoned Preference Data

Reinforcement Learning from Human Feedback (RLHF) is a popular method for aligning Language Models (LM) with human values and preferences. RLHF requires a large number of preference pairs as training data, which are often used in both the Supervised Fine-Tuning and Reward Model training and therefore publicly available datasets are commonly used. In this work, we study to what extent a malicious actor can manipulate the LMs generations by poisoning the preferences, i.e., injecting poisonous preference pairs into these datasets and the RLHF training process. We propose strategies to build poisonous preference pairs and test their performance by poisoning two widely used preference datasets. Our results show that preference poisoning is highly effective: injecting a small amount of poisonous data (1-5\% of the original dataset), we can effectively manipulate the LM to generate a target entity in a target sentiment (positive or negative). The findings from our experiments also shed light on strategies to defend against the preference poisoning attack.

cs.CL↗