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En Wang

Publications and source records attributed to En Wang.

At least 19 recordsLinked to original sources

GeoBridge++: Fact-Guided Geo-Semantic Bridging for Unified Cross-View Geo-Localization

Cross-view geo-localization infers a location by retrieving geo-tagged reference images matching a query image. However, the traditional satellite-centric paradigm limits robustness when high-resolution or up-to-date satellite imagery is unavailable and underexploits complementary cues across views and modalities. To address these challenges, we propose GeoBridge, a novel model that performs bidirectional matching across views and supports language-to-image retrieval. GeoBridge builds on a novel semantic-anchor mechanism that bridges multi-view features through textual descriptions for robust, flexible localization. We further extend GeoBridge to propose GeoBridge++, a fact-guided geo-semantic bridging framework incorporating real-world geographic knowledge to reduce the ambiguity and instability in appearance-dominated supervision. It integrates structured geographic attributes with visual observations to construct factual descriptions and applies targeted guidance based on modality-specific observable content, thereby enhancing geographic discriminability. GeoBridge++ exploits explicit spatial structures encoded by static maps to build a geo-semantic bridge that adaptively aggregates complementary multi-view information and promotes cross-view consistency. In support of this task, we further construct GeoLoc-MM, a million-scale, multi-view, and multi-scale dataset with aligned drone, satellite, street-view, and static-map imagery at six spatial extents per location, enabling systematic evaluation of arbitrary cross-view retrieval, scale robustness, and cross-view generalization. Extensive experiments show that GeoBridge supports robust cross-view and cross-modal geo-localization, while GeoBridge++ achieves consistent improvements across multiple benchmarks. Code and dataset will be released at https://github.com/MiliLab/GeoBridge.

cs.CV

Revisiting the $Λ_c^+ \to nπ^+η$ decay in light of the BESIII measurement

Motivated by the latest BESIII measurements on $Λ_c^+\to nπ^+η$, we perform a systematic theoretical study of this decay. We take into account contributions from the $N(1535)$ state dynamically generated by $S$-wave pseudoscalar meson-octet baryon interactions, the $a_0(980)$ resonance originating from the $S$-wave pseudoscalar meson-pseudoscalar meson interactions, together with the intermediate states $N(1440)$ and $a_2(1320)$. Our results indicate that $a_0(980)$ provides a significant contribution to this process. The inclusion of $a_2(1320)$ hardly improves the fitting quality, while the nucleon resonances play a crucial role in describing the experimental behavior of the $π^+η$ invariant mass spectrum in both low and high energy regions. Restricted by insufficient experimental statistics and a coarse bin size of 33 MeV, the precise contribution fraction of $a_0(980)$ cannot be reliably extracted. We propose future higher-precision and higher-statistics experimental measurements of $Λ_c^+\to nπ^+η$, which can help reveal the intrinsic nature of $a_0(980)$ and quantify the roles of different excited nucleon states in this decay.

hep-ph

Role of $K^*_0(700)$ exchange in the $p \bar{p} \to Λ\barΛ$ reaction

Based on the effective Lagrangian approach, we investigate the $p \bar{p} \to Λ\barΛ$ reaction. Within this framework, we provide a dynamical explanation by analyzing its total and differential cross sections, as well as the polarization of the produced $Λ$ hyperon. Incorporating the $t$-channel exchange of the scalar $K^*_0(700)$ and pseudoscalar $K$ mesons, complemented by an $s$-channel contribution from the vector excited state, we can reproduce the current experimental data fairly well in a wide energy region. Compared to the conventional $K$ and $K^*(892)$ mesons exchange, the $K^*_0(700)$ meson exchange plays a more essential role in simultaneously capturing the observed features of the total and differential cross sections. The introduction of the vector $s$-channel resonance improves the description of the spin observables. This work gives a perspective to inspect the role of $K^*_0(700)$ and serves as a test to search for the resonances in the reaction $p \bar{p} \to Λ\barΛ$ at threshold.

hep-ph

Identifying $Σ(1380)$ and $Σ(1430)$ in the $J/ψ\to Λπ\barΣ$ reaction

We study the $J/ψ\to Λπ\barΣ$ reaction by looking at the $π^+ Λ$ mass distribution at low energies, in search of signals for the low lying $Σ^+$ states. Apart from a clear signal of the $Σ(1385) (3/2^+)$ state, we find a smaller peak for the predicted $Σ(1430) (1/2^-)$, which has already been confirmed by the Belle Collaboration. A first analysis, considering only the $πΛ$ interaction, shows that the low energy part of the spectrum is better reproduced including contributions from the $Σ(1430)$ and the predicted $Σ(1380)(1/2^-)$ state that has been claimed before from analyses of different experiments. However, when we consider the $π\barΣ$ interaction the need for the $Σ(1380)$ disappears.

hep-ph

Unveiling the elusive $Σ(1380)$ resonance through coupled-channel dynamics in $Λ_c^+\toηπ^+Λ$ reaction

We investigate the $Λ_c^+ \to ηπ^+ Λ$ decay measured by the Belle and BESIII Collaborations, focusing on the possible role of the $Σ(1380)$ state with spin-parity $J^P=1/2^-$. In our theoretical framework, the $Λ(1670)$ and $a_0(980)$ are dynamically generated from meson-baryon and meson-meson final-state interactions, respectively, and the corresponding line shapes of these two states used here are applicable to all relevant hadronic reactions. Furthermore, the contributions from the intermediate $Σ(1385)$ resonance and the possible $Σ(1380)$ state are included explicitly. By comparing the invariant mass and angular distributions obtained with and without the $Σ(1380)$ state, we demonstrate that this state plays an important role in improving the description of the experimental data. We also identify the kinematic regions most sensitive to the possible $Σ(1380)$ contribution. Future high-precision measurements of this process will be instrumental for testing the existence of the $Σ$ state with $J^P=1/2^-$.

hep-ph

Finding a clean process $B^- \to K^- D^0 K^0$ to probe absolutely exotic four-quark states

Motivated by the observations of $T_{c\bar{s}0}(2900)^0$ and $T_{c\bar{s}0}(2900)^{++}$, we propose to search for $\tcsbar^0$ in the cleaner process $B^- \to K^- D^0 K^0$. In the $D^*K^*$ molecular picture, our estimates suggest that $T_{c\bar{s}0}(2900)^0$ should contribute significantly to the $D^0 K^0$ invariant mass distribution in $B^- \to K^- D^0 K^0$, as reported by the Belle II Collaboration. The corresponding fit fraction is estimated to be $(9.72\pm 3.92)\%$ or $(7.09\pm 5.88)\%$ in different fitting schemes. Further precise measurements of this process at Belle II and LHCb could be helpful for clarifying the nature of $T_{c\bar{s}0}(2900)$.

hep-ph

Search for the low-lying excited baryon $Σ^*(1/2^-)$ through process $Λ^+_c \to ΛK^0 π^+$

Motivated by recent BESIII measurements of the singly Cabibbo-suppressed processes $Λ^+_c \to ΛK^+ π^0$ and $Λ^+_c \to ΛK_S^0 π^+$, we investigate the process $Λ^+_c \to ΛK^0 π^+$ by taking into account the contribution from the low-lying excited baryon $Σ^*(1/2^-)$, dynamically generated via the $S$-wave pseudoscalar meson-octet baryon interaction, as well as from the intermediate resonances $K^*(892)$ and $N(1535)$. Our model successfully reproduces the BESIII $π^+K^0$ invariant mass distribution, and predicts a distinct cusp structure around 1.43~GeV in the $π^+Λ$ invariant mass distribution, which is associated with the predicted $Σ^*(1/2^-)$. Future high-precise measurements of this process at BESIII, Belle~II, and the proposed Super Tau-Charm Facility experiments will be crucial for testing the existence of $Σ^*(1/2^-)$ and advancing our understanding of the light baryon spectrum.

hep-ph

Probing the isospin structure and low-lying resonances in $Λ_c^+ \to n\bar{K}^0 π^+$ decays

The Cabibbo-favored decay $Λ_c^+ \to n \bar{K}^0π^+$ offers a unique window to explore unresolved puzzles in the low-energy baryon spectroscopy and the isospin dynamics of the $\bar{K}N$ system. Recent experimental results present a, for now, contradiction: LHCb and Belle analyses of $Λ_c^+ \to p K^-π^+$ suggest the $pK^-$ ($I=0$) component dominates, while the Beijing Spectrometer III (BESIII) hints at significant contributions from both isospin $0$ and $1$ in the $n\bar{K}^0$ system of $Λ_c^+ \to n K_S^0 π^+$. Furthermore, the measured branching fraction of $Λ_c^+ \to n K_S^0 π^+$ exceeds SU(3) symmetry predictions by a factor of 3-4, signaling strong contributions from low-lying resonances. In this work, we provide a theoretical analysis of $Λ_c^+ \to n \bar{K}^0π^+$ within the coupled-channel chiral unitary approach, where the $N(1535)$ and $Λ(1670)$ can be dynamically generated. Our calculations show a narrow peak from $N(1535)$ in the $π^+ n$ invariant mass spectrum and a distinct dip from $Λ(1670)$ in the $\bar{K}^0 n$ spectrum. The dip structure is qualitatively consistent with the $Λ(1670)$ manifestation in $\bar{K}N \to \bar{K}N$ scattering, supporting its molecular interpretation. This study not only connects the experimental observations but also highlights $Λ_c^+ \to n \bar{K}^0π^+$ as a crucial process to disentangle the nature of $N(1535)$ and $Λ(1670)$. Future precise measurements of this decay channel by the BESIII, Belle II, LHCb, and the proposed Super Tau-Charm Factory are strongly encouraged.

hep-ph

Token-Level Policy Optimization: Linking Group-Level Rewards to Token-Level Aggregation via Sequence-Level Likelihood

Group Relative Policy Optimization (GRPO) has significantly advanced the reasoning ability of large language models (LLMs), particularly in their mathemat ical reasoning performance. However, GRPO and related entropy regularization methods still struggle with token-level sparse-rewards, which is an inherent chal lenge in chain-of-thought (CoT) reasoning. These approaches often rely on undifferen tiated token-level entropy regularization, which easily leads to entropy collapse or model degradation under sparse token rewards. In this work, we propose TEPO, a novel token-level framework that (1) leverages sequence-level likelihood to link group-level rewards with individual tokens via token-level aggregation, and (2) introduces a token-level KL-Divergence mask constraint that targets tokens with positive advantages and decreasing entropy to mitigate abrupt policy updates. Experiments demonstrate that TEPO not only achieves state-of-the-art performance on mathematical reasoning benchmarks but also markedly enhances training stability, reducing convergence time by 50% compared with GRPO/DAPO.

cs.CL

The dynamically generated $N(1535)$ state in the $Λ_c^+ \to p\bar{K}^0 π^0$ decay

We present a theoretical analysis of the process $Λ_c^+ \to p\bar{K}^0 π^0$ within the chiral unitary approach, with particular emphasis on the dynamically generated $N(1535)$ resonance. In addition to $N(1535)$, our model incorporates contributions from other intermediate resonances including $N(1650)$, $K^*(892)$, $K_0^*(1430)$, $N(1440)$, and $Σ(1750)$. The calculated invariant mass distributions and Dalitz plot are in good agreement with the recent Belle measurements. Our analysis highlights the crucial role of $N(1535)$ state in this decay channel and supports its interpretation as a dynamically generated state arising from coupled-channel meson-baryon interactions.

hep-ph

Role of $Σ(1660)$ in the $K^- p \toπ^0π^0Σ^0$ reaction

The processes of $K^-p \to π^0 π^0 Σ^0$ and $K^- p \to π^0 Λ(1405)$ are studied within the effective Lagrangian approach. In addition to the ``background" contribution from the $u$-channel nucleon pole term, contribution from the $Σ(1660)$ resonance with spin-parity $J^P=1/2^+$ is also considered. For the $K^-p \to π^0 π^0 Σ^0$ reaction, we perform a calculation for the total and differential cross sections by considering the contribution from the $Σ(1660)$ intermediate resonance decaying into $π^0 Λ(1405)$ with $Λ(1405)$ decaying into $π^0 Σ^0$. With our model parameters, the available experimental data on both the $K^-p \to π^0 π^0 Σ^0$ and $K^- p \to π^0 Λ(1405)$ reactions can be fairly well reproduced. It is shown that we really need the contribution from the $Σ(1660)$ resonance, and that these experimental measurements could be used to determine some properties of the $Σ(1660)$ resonance.

hep-ph

Token-Level Policy Optimization: Linking Group-Level Rewards to Token-Level Aggregation via Markov Likelihood

Group Relative Policy Optimization (GRPO) has significantly advanced the reasoning ability of large language models (LLMs), particularly by boosting their mathematical performance. However, GRPO and related entropy-regularization methods still face challenges rooted in the sparse token rewards inherent to chain-of-thought (CoT). Current approaches often rely on undifferentiated token-level entropy adjustments, which frequently lead to entropy collapse or model collapse. In this work, we propose TEPO, a novel token-level framework that incorporates Markov Likelihood (sequence likelihood) links group-level rewards with tokens via token-level aggregation. Experiments show that TEPO consistently outperforms existing baselines across key metrics (including @k and accuracy). It not only sets a new state of the art on mathematical reasoning tasks but also significantly enhances training stability.

cs.CL

Roles of $a_0(980)$ and $a_0(1710)$ in Cabibbo-suppressed process $D^+\to π^0π^+η$

Motivated by the BESIII amplitude analysis of the single Cabibbo-suppressed process $D^+\to π^0π^+η$, we investigate this reaction by taking into account the contributions from the $a_0(980)$, $ρ$, and $a_0(1710)$, where the scalar meson $a_0(980)$ could be dynamically generated from the $S$-wave pseudoscalar meson-pseudoscalar meson interaction within the chiral unitary approach. Our theoretical predictions for the $π^0η$, $π^+η$, and $π^+π^0$ invariant mass distributions are in agreement with the BESIII measurements, especially the clear peaks around 1~GeV in the $π^0η$ and $π^+η$ invariant mass distributions could be associated with the dynamically generated state $a_0(980)$. Furthermore, we demonstrate that the intermediate $a_0(1710)$ is also necessary to describe the enhancement structure around $1.6\sim 1.7$~GeV in the $π^{0/+}η$ invariant mass distribution. More precise experimental measurements of this process could provide deeper insights into the nature of the scalar mesons $a_0(980)$ and $a_0(1710)$.

hep-ph

The $B^-\to J/ψη^\prime K^-$ reaction and the $Y(4710)$ and $K_0^*(1430)$ contributions

Motivated by the recent LHCb Collaboration analysis, we have investigated the process $B^-\to J/ψη^\prime K^-$ by considering the contributions from the resonances $Y(4710)$ and $K_0^*(1430)$. Our results are in good agreement with the measured invariant mass distributions and the Dalitz plot of LHCb, which supports the existence of the $K_0^*(1430)$ and the $Y(4710)$ in the process $B^-\to J/ψη^\prime K^-$. Since the decay mode of $Y(4710)\to J/ψη'$ is Okubo-Zweig-Iizuka (OZI) suppressed for the charmonium state, the measurements of the $\mathcal{B}(Y(4710)\to J/ψη')$ through the process $B^-\to J/ψη' K^-$ or other processes is helpful to understanding the nature of the $Y(4710)$. Thus, we advocate that Belle~II and LHCb Collaborations could perform the more precise analysis to confirm the evidence of the $Y(4710)$ state, which could be helpful to reduce the experimental uncertainties of its mass and width, and to explore its nature.

hep-ph

Hadronic decay $D^+\toπ^+ηη$ and the $a_0(980)$ and $f_0(1370)$ contributions

Motivated by the resent BESIII Collaboration measurements of the process $D^+\toπ^+ηη$, we investigate this process by considering the contribution from the resonance $a_0(980)$, which is generated by $S$-wave pseudoscalar meson-pseudoscalar meson interaction, and the contribution from the intermediate scalar meson $f_0(1370)$. Our results could give a good description of the $π^+η$ and $ηη$ invariant mass distributions, which implies that the contribution from the intermediate $f_0(1370)$, neglected in BESIII analysis, could play a role in this process. Furthermore, the predicted Dalitz plots are also consistent with the BESIII measurements. The more precise measurements about this process in future could shed light on the mechanism of this process and the properties of $f_0(1370)$ and $a_0(980)$.

hep-ph

Strangeonium spectrum with the screening effects and interpretation of $h_1(1911)$ and $X(2300)$ observed by BESIII

Motivated by two news states $h_1(1911)$ and $X(2300)$ observed by BESIII, we have investigated the mass spectrum and the strong decay properties of the strangeonium mesons within the modified Godfrey-Isgur model by considering the screening effects. We have determined the free parameters using the masses and widths of the well established $s\bar{s}$ states $ϕ(1020)$, $ϕ(1680)$, $h_1(1415)$, $f_2^\prime(1525)$, and $ϕ_3(1850)$. According to our results, $h_1(1911)$ and $X(2300)$ could be well explained as states $h_1(2^1P_1)$ and $h_1(3^1P_1)$ $s\bar{s}$ states, respectively. Meanwhile, the possible assignments of $X(2000)$, $η_2(1870)$, and $ϕ(2170)$ as $3^3S_1$, $1^1D_2$, and $2^3D_1$ are also discussed. Furthermore, the masses and widths of the $2S$, $3S$, $1P$, $2P$, $3P$, $1D$, and $2D$ $s\bar{s}$ states are also given and compared with various theoretical predictions, which is helpful for the observations and confirmations of these states in future.

hep-ph

Revisiting the $Λ_c^+\to Ληπ^+$ and the roles of intermediate resonances

In this paper, we first review the theoretical and experimental studies of the process $Λ_c^+ \to π^+ ηΛ$. Motivated by the recent BESIII and Belle measurements, we have conducted a theoretical study of the process $Λ_c^+ \to π^+ ηΛ$, where the $a_0(980)$ and $Λ(1670)$ resonances are dynamically generated from the $S$-wave meson meson and meson baryon interaction, respectively. Our results give a reasonable description of the invariant mass distributions, which implies that the spin flip contribution in the $Σ(1385)$ excitation plays an important role.

hep-ph

Flavor Physics at the CEPC: a General Perspective

We discuss the landscape of flavor physics at the Circular Electron-Positron Collider (CEPC), based on the nominal luminosity outlined in its Technical Design Report. The CEPC is designed to operate in multiple modes to address a variety of tasks. At the $Z$ pole, the expected production of 4 Tera $Z$ bosons will provide unique and highly precise measurements of $Z$ boson couplings, while the substantial number of boosted heavy-flavored quarks and leptons produced in clean $Z$ decays will facilitate investigations into their flavor physics with unprecedented precision. We investigate the prospects of measuring various physics benchmarks and discuss their implications for particle theories and phenomenological models. Our studies indicate that, with its highlighted advantages and anticipated excellent detector performance, the CEPC can explore beauty and $τ$ physics in ways that are superior to or complementary with the Belle II and Large-Hadron-Collider-beauty experiments, potentially enabling the detection of new physics at energy scales of 10 TeV and above. This potential also extends to the observation of yet-to-be-discovered rare and exotic processes, as well as testing fundamental principles such as lepton flavor universality, lepton and baryon number conservation, etc., making the CEPC a vibrant platform for flavor physics research. The $WW$ threshold scan, Higgs-factory operation and top-pair productions of the CEPC further enhance its merits in this regard, especially for measuring the Cabibbo-Kobayashi-Maskawa matrix elements, and Flavor-Changing-Neutral-Current physics of Higgs boson and top quarks. We outline the requirements for detector performance and considerations for future development to achieve the anticipated scientific goals.

hep-ex