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

We investigate the cosmological implications of an extended gravitational framework based on biconnection gravity, constructed from the Schr $$\ddot{\textrm{o}}$$ dinger connection and its dual. In this approach, the difference between the two connections defines the mutual curvature, which encodes the non-Riemannian geometric degrees of freedom, while their symmetric combination reduces to the Levi-Civita connection and hence reproduces general relativity at the background level. Within this setting, we derive the generalized Friedmann equations for a spatially flat Friedmann–Lemaître–Robertson–Walker Universe. The resulting equations contain additional geometric contributions that may naturally encode an effective dark energy sector induced by the biconnection degrees of freedom. We explore this extra dark energy by adopting five commonly used parametrizations, namely B $$\Lambda $$ CDM, $$\omega $$ CDM, Chevallier–Polarski–Linder, Barboza–Alcaniz, and a logarithmic equations of state. These considerations are confronted with recent observational data, including DESI DR2, Pantheon $$^+$$ , and CC observations. Our analysis shows that the four parameterizations enter the acceleration phase at almost the same redshifts and share the same current value of the Hubble rate. Furthermore, the statistical comparison based on the Akaike, Bayesian, and Deviance Information Criterion shows that Barboza–Alcaniz, and logarithmic parameterizations have strong evidence and are competitive with $$\Lambda $$ CDM. To classify this biconnection gravity in the plethora theoretical models describing the current cosmic acceleration, we examine its implications through cosmographic tools, including the deceleration, jerk, and snap parameters, as well as through the Statefinder analysis and $\textit{Om}$($\textit{z}$) diagnostic. These diagnostics indicate that the geometric sector generates a dynamical dark energy component that remains observationally close to $$\Lambda $$ CDM at the background level. Indeed, the effective evolution of the biconnection gravity begins initially from a quintessence-like regime and subsequently evolves toward a phantom-like regime. All parameterizations under consideration face this transition in the recent past, except for the $$\omega $$ CDM model, which enters the phantom-like regime in the future.

Morocco

D. Mhamdi

A. Bouali

T. Ouali

Romania

T. Harko

Cosmological test of a length-preserving biconnection gravity

In ultra high-energy collisions, nuclei with very low binding energies are not expected to survive the dense and hot final state environment. The traditional view has therefore been that nuclei form via coalescence after the hot environment has dissipated. However, statistical thermal models, where hadrons are produced from a fireball at thermal equilibrium, can describe the relative abundances of light nuclei in pp and heavy-ion collisions at the LHC equally well. In this paper we investigate if balance functions triggered by protons and deuterons can be used to distinguish between the two production mechanisms. The coalescence model is investigated using PYTHIA, while the statistical thermal model is examined using the Thermal FIST package. We find that for both models the same simple relation between proton and deuteron triggered balance functions is applicable. However, there is a striking difference between the two models when the transverse momentum of trigger particles is varied. This dependence offers a promising observable to discriminate between the two models that goes beyond nuclei production. Furthermore, we find that deuteron-meson balance functions vanish identically for both models due to baryon number conservation and isospin symmetry.

Sweden

Sushanta Tripathy

Peter Christiansen

Confronting the production mechanisms of nuclei with deuteron and proton-triggered balance functions

We establish a general no-inner horizon theorem for a wide class of static anisotropic black holes in Einstein gravity. Working in an orthonormal frame, we show that anisotropic scaling inevitably induces a non-vanishing “effective pressure difference” between spatial directions apart from the radial direction. We prove that, provided this effective pressure difference satisfies a simple integral condition which holds in a general setting, inner (Cauchy) horizons are excluded. As an application, we demonstrate that a large variety of black holes which possess homogeneous but anisotropic three-dimensional horizons can not have inner horizons. These anisotropic horizon geometries fall within various Bianchi types. As a specific example, we investigate the internal structure of a charged black hole solution with a Bianchi type II horizon by combining analytical and numerical methods, and we find the absence of the inner horizon and a stable Kasner universe near the spacelike singularity. Our theorem is consistent with some previously known results, implying an underlying mechanism that certain kinds of spatial anisotropy can remove inner horizons. Consequently, anisotropic black holes generically develop spacelike singularities in their interiors, offering new insight into the interplay between anisotropy, strong cosmic censorship, and black hole interior structures.

Yuxuan Peng

Yu-Sen An

On the absence of inner horizons for anisotropic black holes

In this work, we study lepton flavor violation (LFV) decays within the framework of the Doublet Left-Right Symmetric model (DLRSM). The model features an extended gauge and scalar sector, including a bidoublet and two doublets that induce new charged current interactions. Spontaneous Symmetry Breaking (SSB) occurs in two stages, introducing a new scale associated with the vacuum expectation value (VEV) of the right-handed doublet which is assumed to lie above the electroweak scale. Neutrino masses are generated via the inverse seesaw (ISS) mechanism, allowing sizable mixing between active and sterile neutrinos. We diagonalize the full neutrino mass matrix and express the mixing in terms of physical parameters. We compute the branching ratios for LFV radiative and Higgs decays as functions of the heavy neutrino mass. Our numerical analysis incorporates current experimental bounds and projected sensitivities, highlighting viable regions of parameter space where LFV signals could be probed at future colliders.

Mexico

M. Zeleny-Mora

R. Gaitán-Lozano

Colombia

R. Martinez

Lepton flavor violating Higgs decays in a minimal doublet left-right symmetric model with an inverse seesaw

Gauss–Bonnet inflation typically affects the dynamics over an extended portion of the trajectory, making it difficult to isolate a controlled imprint at CMB scales. We consider a trajectory-selective coupling $$\mu (\phi ,X)$$ that gates the Gauss–Bonnet sector in phase space, enabling the higher-curvature contribution to be localized within a finite e-fold window while remaining negligible elsewhere. We identify stable inflationary solutions consistent with this localization and enforce standard ghost and gradient stability conditions for both scalar and tensor perturbations. For these viable backgrounds we compute pivot-scale observables and examine their dependence on the overall Gauss–Bonnet strength and on the kinetic gating. The framework offers a controlled route for realizing localized higher-curvature effects with predictable consequences for CMB-scale measurements.

Iran

Ali Seidabadi

Sara Saghafi

Kourosh Nozari

Beyond $$f(\phi ){\mathcal {G}}$$ : Gauss–Bonnet inflation with $$\mu (\phi ,X)$$

A comparative description is made of the measurements at LHC of pp elastic scattering at 13 TeV by the ATLAS and TOTEM Collaborations. In the total and differential cross sections we show that the differences are justified through single numerical factor. It seems that there is no fundamental physical difference, but only a difference of normalization between the two experiments. We study the real and imaginary amplitudes disentangled with the KFK (Kohara–Ferreira–Kodama) model and show that the properties are similar in qualitative aspects for both experiments. The real and imaginary parts have different slopes at the origin and present zeros, with distributions that are common to several models, with three zeros in the real part and one zero in the imaginary amplitude. A zero in the real part, known as Martin’s zero, influences the determination of the $$\rho $$ parameter.

Brazil

E. Ferreira

T. Kodama

France

A. Kohara

Analysis of ATLAS pp elastic measurements at $$\sqrt{s}$$ = 13 TeV and comparison with TOTEM measurements