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

China

Xing-Yi Ji

Si-Wei Liu

Wen-Tao Lyu

De-Min Li

En Wang

Ju-Jun Xie

Role of Σ(1660) in the $\textit{K}$ $^{−}$ $\textit{p}$ → $\textit{π}$ $^{0}$ $\textit{π}$ $^{0}$Σ$^{0}$ reaction * Supported by the National Key R&D Program of China (2023YFA1606703, 2024YFE0105200), the National Natural Science Foundation of China (12435007, 12475086, 12192263, 12361141819, 1252200936), the Natural Science Foundation of Henan (232300421140, 252300423951) and the Zhengzhou University Young Student Basic Research Projects (PhD students) (ZDBJ202522)

We have performed an updated analysis of the angular distribution of the $ \psi(3686) \to p\bar{p} $ decay by considering transverse beam polarization to investigate potential sources of forward-backward asymmetry and azimuthal modulation beyond the simple $ 1+\alpha\cos^2\theta $ form. We focus on the interference between the $ \psi(3686) $ resonance and two-photon exchange continuum process, as well as on the background from initial-state–final-state radiation (ISR–FSR) interference. A maximum-likelihood fit to the $ \cos\theta $ distribution of $ \psi(3686)\to p\bar{p} $ yields $ \alpha = 1.00 \pm 0.03 $ , which is consistent with previous results. Our model predicts a significant $ \sin(2\phi) $ modulation in the azimuthal angle, indicating the influence of transverse beam polarization. Based on these findings, two-dimensional angular analyses can be conducted in the future to fully disentangle the polarization and interference dynamics in charmonium decays to baryon pairs.

Zhi Gao

Rong-Gang Ping

Minggang Zhao

Update analysis of $ {\psi(3686)\to p\bar{p}}$ * The work is partly supported by the National Natural Science Foundation of China(NSFC) (12575112)

This study investigates the ultraviolet realization of semileptonic four-fermion operator $ O_{ledq}^{\alpha \beta 11} $ that incorporates Majorana dark matter (DM) in both lepton-flavor-conserving (LFC) and lepton-flavor-violating (LFV) scenarios at the one-loop level via box diagram, thereby effectively alleviating the lower bounds on the new physics scale. In addition, we investigate the interplay between model-independent constraints on the Wilson coefficients and DM direct detection, relic density, and collider searches in the context of fermion portal DM model with two mediators. We found that both the projected future constraint on the LFC Wilson coefficient $ C_{ledq}^{2211}/\Lambda^2 \lt $ $ (12.3\; \text{TeV})^{-2} $ from the measurements of neutrino non-standard interaction in the next-generation neutrino oscillation experiments, and the LFV constraint $ C_{ledq}^{1211}/\Lambda^2 \lt \left(2.2\times 10^3\; \text{TeV} \right)^{-2} $ from ongoing charged-lepton-flavor-violation searches, provide a complementary exploration of the parameter space encompassing the DM and scalar masses. With a colored mediator mass of approximately $ 2\; \text{TeV} $ , the sensitivity of the indirect constraints on the four-fermion operator can surpass those of collider searches and DM direct detection, in scenarios where the masses of the DM and scalar are close. By ensuring the correct DM relic density, however, we find that the collider searches and DM direct detection are more sensitive to the electroweak-scale DM and scalar than indirect constraints.

Yuxuan He

Gang Li

Jia Liu

Xiao-Ping Wang

Xiang Zhao

Lepton flavor of four-fermion operator and fermion portal dark matter * Gang Li and Xiang Zhao are supported by the National Natural Science Foundation of China (12347105, 12505127), the Guangdong Basic and Applied Basic Research Foundation (2024A1515012668). The work of Jia Liu is supported by the National Science Foundation of China (12235001, 12475103) and State Key Laboratory of Nuclear Physics and Technology (NPT2025ZX11). The work of Xiao-Ping Wang is supported by National Science Foundation of China (12375095) and the Fundamental Research Funds for the Central Universities

We have performed a next-to-leading-order (NLO) QCD sum rules analysis of the $1^{-+}$ light tetraquark states. By investigating various compact and molecular tetraquark currents, we extracted the mass spectra of the corresponding states, all of which lie above $1.7\,\text{GeV}$ . We have identified multiple $1^{-+}$ states around $2.0\,\text{GeV}$ matching well with $\pi_{1}(2015)$ , confirming that $\pi_{1}(2015)$ is an excellent tetraquark candidate. By contrast, our calculations exclude the possibility that the $\pi_{1}(1400)$ is a tetraquark or hybrid–tetraquark mixture. This result suggests that it may not exist, which is consistent with recent experimental results.

Wei-Yang Lai

Hong-Ying Jin

NLO QCD sum rules analysis of 1$^{− +}$ tetraquark states

The classical no-hair theorem states that stationary black holes in general relativity can be completely described by only a small set of global parameters. Within this framework, no additional geometric structures are expected to persist outside the event horizon. However, quantum vacuum polarization may introduce small modifications to the near-horizon geometry, effectively giving rise to what is known as quantum hair. Such corrections may provide a possible window into the microscopic structure and thermodynamic properties of black holes. In this work, we examine how the quantum hair parameter $$\gamma $$ influences the periodic orbital dynamics of test bodies in extreme mass-ratio inspirals (EMRIs) and their associated gravitational-wave emission. We find that $$\gamma $$ significantly modifies the characteristic radii and angular momenta of two important circular orbits, namely the marginally bound orbit (MBO) and the innermost stable circular orbit (ISCO), leading to a shift in the allowed region of the energy–angular momentum ($\textit{E}$–$\textit{L}$) phase space. Based on the rational number $\textit{q}$ classification, we further show that quantum corrections tend to enhance the zoom–whirl orbital behavior. Within the conservative Numerical Kludge framework adopted in this work, the quantum hair parameter modifies the effective potential and induces small shifts in the fundamental orbital frequencies, which in turn produce cumulative phase differences in long-duration waveform evolutions. These results provide an illustrative example of how quantum-corrected geometry can affect conservative orbital dynamics and waveform phasing, and they offer a phenomenological basis for future, more complete studies of possible quantum-gravity imprints in EMRI signals.

Yiru Zhang

Meirong Tang

Zhaoyi Xu

Periodic orbits and gravitational radiation from extreme mass-ratio inspirals as probes of black hole quantum hair

We present a global analysis of the current $\textit{B}$-meson flavor anomalies and extend it to the baryonic sector through the decay $$\Lambda _b^0 \rightarrow \Lambda _c^+(\rightarrow \Lambda ^0 \pi ^+) \tau ^-(\rightarrow \pi ^- \nu _\tau ){\bar{\nu }}_\tau $$ . The lepton flavor universality ratios $$R_{\tau /(\mu ,e)}(D^{(*)})$$ , measured by BaBar, Belle, and LHCb, exhibit a combined $$3.8\sigma $$ deviation from Standard Model (SM) predictions. Using the latest HFLAV averages and imposing $$B_c$$ -lifetime constraints on the branching ratio, $${\mathcal {B}}(B_c \rightarrow \tau \nu ) < 60\%, 30\%, 10\%$$ , we perform a global fit to the anomaly data and propagate the preferred new physics (NP) solutions to the full cascade decay $$\Lambda _b^0 \rightarrow \Lambda _c^+(\rightarrow \Lambda ^0 \pi ^+) \tau ^-(\rightarrow \pi ^- \nu _\tau ){\bar{\nu }}_\tau $$ . The mixed vector-scalar scenario $$(C_{V_L},C_{S_R})$$ emerges as the most favored NP solution, yielding the largest pull from the SM while remaining insensitive to branching-ratio constraints. The single-operator $$C_{V_L}$$ case identified as the next most competitive scenario. We study the impact of NP vector, scalar and tensor operators on a complete set of angular observables on the five-fold $$\Lambda _b$$ decay using Lattice-QCD form factors and find that the scenarios $$(\Re [C_{S_L}=4C_T],\Im [C_{S_L}=4C_T])$$ and $$(C_{S_L},C_{S_R})$$ generate the largest deviations from the SM predictions. In particular, the observables $${\mathcal {K}}_{1c}$$ , $${\mathcal {K}}_{2ss}$$ , $${\mathcal {K}}_{2cc}$$ , and $${\mathcal {K}}_{4s}$$ show the highest sensitivity to NP effects. The correlation analysis reveals distinctive NP patterns: the $$(\Re [C_{S_L}=4C_T],\Im [C_{S_L}=4C_T])$$ scenario exhibits inverse correlations among $${\mathcal {K}}_{1c}$$ and $${\mathcal {K}}_{2ss,2cc,4s}$$ and direct correlations between $${\mathcal {K}}_{2ss}$$ and $${\mathcal {K}}_{2cc,4s}$$ , pointing to destructive helicity interference and a possible CP-violating phase, while the $$(C_{S_L},C_{S_R})$$ scenario displays complementary behavior consistent with CP-conserving dynamics. These results establish baryonic semileptonic decays as a powerful and independent probe of the $$R_{\tau /(\mu ,e)}(D^{(*)})$$ anomalies, with future measurements providing critical tests of the underlying NP structure.

Pakistan

Muhammad Arslan

Ishtiaq Ahmed

Muhammad Aslam

The angular observables of $$\Lambda _b \rightarrow \Lambda _c(\rightarrow \Lambda ^0 \pi ^+) \, \tau ^-(\rightarrow \pi ^- \nu _\tau )\, {\bar{\nu }}_\tau $$ within the paradigm of FCCC anomalies

We investigate the emergence of spacetime geometry within the AdS/CFT correspondence by explicitly incorporating quantum coherence effects arising from finite coherent superpositions of closed-string modes forming mesoscopic quantum D-branes. We show that the stage at which quantum coherence is suppressed relative to the construction of the emergent geometry significantly influences the resulting spacetime structure. Suppressing coherence prior to constructing the effective geometric description yields a purely classical Anti-de Sitter (AdS) geometry, whereas constructing the geometry from a coherent state and only subsequently suppressing interference leads to controlled quantum corrections of order $$O(M^{-2})$$ to the AdS background. We further demonstrate that both microscopic coherence between string modes and mesoscopic coherence among D-branes distinctly shape the resulting spacetime structure, introducing measurable quantum deviations from classical geometry. Our results provide critical insights into how quantum coherence may underpin the emergence of classical gravity and offer new directions for studying quantum-gravitational phenomena within holographic frameworks.

United States

Andrei Patrascu

Quantum corrections to the AdS bulk from a semiclassical description of D-branes

In this study, we examine a two-level atom freely falling into an effective model of a static, spherically symmetric, nonsingular black hole with holonomy corrections. The quantum correction parameter produces black hole remnants as the size approaches the horizon. In the system, the atom interacts with a massless scalar photon through a Boulware-like vacuum. We discuss how quantum corrections affect the form of the atom’s excitation and absorption probabilities. We find that the excitation probability decreases with increasing quantum correction parameter, whereas the absorption probability increases. We confirm that the Einstein equivalence principle holds for such a system, as expected. We also examined the behavior of the modified horizon brightened acceleration radiation under holonomy corrections. We recover the standard Hawking temperature and Hawking–Bekeinstein entropy when holonomy corrections vanish.

Indonesia

Ar Rohim

Anto Sulaksono

Acceleration radiation of a two-level atom freely falling into a nonsingular black hole with holonomy corrections

<p>In this work we study the relativistic kinetic theory of a boost-invariant conformal gas on a static, maximally symmetric background <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>d</mi><msub><mi>S</mi><mn>3</mn></msub><mo>×</mo><mi mathvariant="double-struck">R</mi></math>, considering all constant-curvature slicings of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>d</mi><msub><mi>S</mi><mn>3</mn></msub></math>—flat, spherical, or hyperbolic—and their associated symmetry groups. Using a symmetry-driven cotangent bundle approach, we show that the isometry group of each slicing acts on phase space in such a way that only its Casimir invariants and the timelike coordinate are unconstrained, so the distribution function depends solely on these quantities. This yields a unified boost-invariant exact solution of the Boltzmann equation valid for each constant–curvature foliation of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>d</mi><msub><mi>S</mi><mn>3</mn></msub><mo>×</mo><mi mathvariant="double-struck">R</mi></math>. Specializing this general solution to the flat and spherical foliations reproduces the Bjorken and Gubser flows, respectively, while its restriction to the hyperbolic foliation produces a genuinely new analytic solution (“Grozdanov flow”). Hydrodynamics and free streaming emerge naturally as limiting regimes of this novel exact solution. We further comment on several relevant aspects of the new boost-invariant solution on the hyperbolic slicing and on their interpretation once mapped back to Minkowski space.</p>

Mauricio Martinez

Christopher Plumberg

Maximally symmetric boost-invariant solutions of the Boltzmann equation in foliated geometries

<p>In the present work, I explore the production of <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msup><mi mathvariant="normal">Ξ</mi><mn>0</mn></msup><msup><mover accent="true"><mi mathvariant="normal">Ξ</mi><mo>¯</mo></mover><mn>0</mn></msup></mrow></math> using <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup></mrow></math> collision data at ten center-of-mass energies between 3.51 and 4.95 GeV collected with the BESIII detector at the BEPCII collider and corresponding to an integrated luminosity of 30 <math xmlns="http://www.w3.org/1998/Math/MathML"><msup><mrow><mi>fb</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></math> to study the structure of baryons. The data collected by the BESIII detector are useful for the study of XYZ states, and this collaboration continues the exploration of these exotic charmoniumlike states. At higher center-of-mass energies the baryon-antibaryon pair production in electron-positron annihilation provides a powerful tool. In this paper, I investigate a hyperon pair produced in the electron-positron annihilation reactions, and I present the phenomenological results for the process using the BESIII detector at the BEPCII collider. In the reaction <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup><mo>→</mo><msup><mi mathvariant="normal">Ξ</mi><mn>0</mn></msup><msup><mover accent="true"><mi mathvariant="normal">Ξ</mi><mo>¯</mo></mover><mn>0</mn></msup></mrow></math>, I consider two different contributions: one from the <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>D</mi></math>-meson loop and the other from the three-gluon charmonium annihilation. In this process I calculate the total cross section including the contributions of the <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>D</mi></math>-meson loop and three-gluon loops as well as the interference of all diagrams. In the case of a purely electromagnetic mechanism for these contributions, large relative phases are generated. For a large momentum transferred region I get as a byproduct a fit of the electromagnetic form factor of the <math xmlns="http://www.w3.org/1998/Math/MathML"><msup><mi mathvariant="normal">Ξ</mi><mn>0</mn></msup></math> hyperon. In the present work, in addition to the <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>ψ</mi><mo>(</mo><mn>3770</mn><mo>)</mo></mrow></math> charmonium, I also take into account the contributions of other charmonium (-like) states, such as <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>ψ</mi><mo>(</mo><mn>4040</mn><mo>)</mo></mrow></math>, <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>ψ</mi><mo>(</mo><mn>4160</mn><mo>)</mo></mrow></math>, <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>Y</mi><mo>(</mo><mn>4230</mn><mo>)</mo></mrow></math>, <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>Y</mi><mo>(</mo><mn>4360</mn><mo>)</mo></mrow></math>, <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>ψ</mi><mo>(</mo><mn>4415</mn><mo>)</mo></mrow></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>Y</mi><mo>(</mo><mn>4660</mn><mo>)</mo></mrow></math>. On the whole my results are in good agreement with the available experimental data.</p>

JINR

Azad I. Ahmadov

Cross section of the process <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msup><mi>e</mi><mo>+</mo></msup><mo>+</mo><msup><mi>e</mi><mo>−</mo></msup><mo>→</mo><msup><mi mathvariant="normal">Ξ</mi><mn>0</mn></msup><mo>+</mo><msup><mover accent="true"><mi mathvariant="normal">Ξ</mi><mo>¯</mo></mover><mn>0</mn></msup></mrow></math> in the vicinity of charmonium <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>ψ</mi><mo>(</mo><mn>3770</mn><mo>)</mo></mrow></math> and in the charmonium (-like) state including the <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>D</mi></math>-meson loop and three-gluon contributions