In this work, we investigate the production and decay of molecular states with quark content $cc\bar c\bar q$ and $J^P=1^+$ using a phenomenological analysis and an effective Lagrangian approach. Based on an $\textit{SU}$(3) flavor-symmetry analysis to identify golden channels, we further explore the dynamics of these processes under the molecular assumptions of ${\eta_c D^*}$ and ${J/\psi D^*}$ . Our results indicate that the production branching ratio in $B_c$ decays is sizable: it can be of order $10^{-4}$ for the molecular configuration ${{\eta}_cD^*}$ and $10^{-5}$ for the molecule ${J/\psi D^*}$ . In addition, we find that the decay widths of the two molecular configurations ${{\eta}_cD^*}$ and ${J/\psi D^*}$ are not significant, at the level of ${\cal{O}}$ ( $\text{MeV}$ ).

China

Na Li

Ye Xing

Jing-Rui Shi

Analysis of molecular state $\textit{η$_{c}$D}$ $^{*}$ and $\textit{J}$/$\textit{ψD}$ $^{*}$ in the effective Lagrangian approach * Supported by the National Natural Science Foundation of China (NSFC) (12005294)

We report stronger evidence for the $X(7200)$ state and markedly improved measurements of the $X(6900)$ resonance parameters based on a combined analysis of the di- $J/\psi$ mass spectrum using published data from LHCb, ATLAS, and CMS. Through simultaneous fits to the datasets from all three experiments, we observe the $X(6900)$ with overwhelming significance ( $ \gt 12\sigma$ ) and determine its mass and width with improved precision. For the $X(7200)$ , we find consistent signals across multiple interference models, with significances ranging from $3.7\sigma$ to $6.6\sigma$ ; in the best-fit model (the CMS three-resonance scheme), the significance reaches $6.6\sigma$ , providing substantially stronger evidence for this state. Our results underscore the essential role of interference effects in fully charmed tetraquark spectroscopy and offer new constraints on their production mechanisms at the LHC.

Yuan Wang

Ran Li

Bin Zhong

Ya-Qian Wang

Enhanced evidence of $\textit{X}$(7200) and improved measurements of $\textit{X}$(6900) parameters from a combined LHCb-ATLAS-CMS analysis * Supported by the National Natural Science Foundation of China (NSFC) (12475077)

The Kerr/CFT correspondence establishes a correspondence between extremal black holes in higher dimensions and a chiral conformal field theory (CFT) in their near-horizon limit. A generalization of this framework, known as the EVH/CFT correspondence, has been developed for four- and five-dimensional AdS black holes. It was further proposed in [ ${\rm{AdS}}_{D=6,7}$ black holes, a generalized duality between $(D-2)$ -dimensional geometry and $(D-3)$ -dimensional field theory may emerge in a suitably defined extremal vanishing horizon (EVH) limit. In this work, we show that, in the EVH limit, the near-EVH geometries of these ${\rm{AdS}}_{D=6,7}$ black holes reduce to lower-dimensional black holes whose metrics are conformally related to solutions of Einstein-Maxwell-Maxwell-dilaton (EMMD) gravity. This structural resemblance suggests a potential route toward the microscopic counting of non-AdS black hole entropy via higher-dimensional AdS/CFT techniques.

Weichao Bu

Yang Lei

Probing decoupled throats of AdS $\textit{D}$ black holes in $\textit{D}$ = 6, 7 * Supported by National Natural Science Foundation of China (NSFC) (2305081), the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD), and the NSFC-Royal Society International Collaboration (W2421035)

The dark matter scattering with atomic bound electrons is a crucial avenue for exploring the sub-GeV mass range. The commonly used factorization, where atomic effects are encoded in an overall form factor multiplying the free-electron scattering matrix element, is not necessarily true. Especially, the free-electron kinematics and phase space cannot consistently apply for off-shell bound electrons. Starting from the first principles of quantum field theory, we establish a theoretically consistent formalism to account for the atomic effects. By taking the scalar-type interaction as an example, we investigate the difference between the non-relativistic and relativistic calculations to show that the relativistic effects can lead to a $$30{-}50\%$$ reduction in the scattering phase space and differential cross section. In other words, not just a theoretically consistent formalism for the atomic effects but also relativistic calculation with Dirac equation are necessary.

Shao-Feng Ge

Japan

Jie Sheng

Chuan-Yang Xing

Relativistic atomic effects of dark matter electron scattering

We investigate the quasinormal modes of polar metric-dilaton perturbations around the dilaton-Euler-Heisenberg (dEH) black holes with dilaton hair. The dEH black holes are obtained from the Einstein–Maxwell-dilaton theory with two dilaton coupling parameters ( $$\alpha ,\beta $$ ) to the nonlinear Euler–Heisenberg term. We compute the quasinormal mode spectra by making use of two numerical techniques: direct integration and matrix values continued fraction methods. An excellent agreement is found between two approaches, confirming the robustness of our computation. We present the fundamental quasinormal frequencies for both gravitational and dilaton modes and analyze their dependence on the magnetic charge ( $$Q_m$$ ), angular momentum quantum number ($\textit{l}$), and coupling parameter ( $$\epsilon =\alpha -\beta $$ ). All negative imaginary quasinormal frequencies for polar metric-dilaton perturbations imply that the dEH black hole with dilaton hair is stable against dilaton with $$l=0,1,2,3$$ and gravitational modes with $$l=2,3$$ . Also, our results reveal distinct qualitative behaviors between $$\epsilon =1$$ and $$\epsilon = -1 $$ , particularly in the damping rates near the extremality.

Sheng-Yuan Li

South Korea

Yun Myung

Ming Zhang

Xufen Zhang

De-Cheng Zou

Polar perturbations of dilaton-Euler–Heisenberg black holes

Recently, the BESIII Collaboration reported the first observation of the decays $$\chi _{cJ} \rightarrow \eta \eta \eta ^\prime $$ in order to search for the $$1^{-+}$$ exotic state $$\eta _1(1855)$$ . A partial wave analysis of the $$\eta \eta ^\prime $$ invariant mass spectrum shows no significant signal for the $$\eta _1(1855)$$ . In this work, we, using an effective Lagrangian approach, investigate the processes $$\chi _{cJ} \rightarrow \eta \eta \eta ^\prime $$ via the box and triangle loops involving charmed mesons and the scalar meson $$f_0(1500)$$ . Our calculations reproduce well the experimental branching fractions of $$\chi _{cJ} \rightarrow \eta \eta \eta ^\prime $$ . Furthermore, we present the predictions of the relevant invariant mass spectra of $$\eta \eta ^\prime $$ and $$\eta \eta $$ produced in the $$\chi _{c1}$$ decay, which seem overall consistent with the BESIII measurements. In the present model, the decay $$\chi _{c1} \rightarrow \eta \eta \eta ^\prime $$ is dominated by the triangle and box loop contributions. The consistency between our theoretical results and the BESIII measurements sheds light on the underlying decay mechanism of the $$\chi _{cJ}$$ decaying into light mesons and might be helpful to understand the absence of the $$\eta _1(1855)$$ signal in the decay channels $$\chi _{cJ} \rightarrow \eta \eta \eta ^\prime $$ .

Xin-Ru Wang

Shu-Qi Wang

Shi-Dong Liu

Qi Wu

Gang Li

Ju-Jun Xie

Study of $$\chi _{cJ}\rightarrow \eta \eta \eta ^\prime $$ via intermediate charmed meson loop mechanisms and its implications for non-observation of $$\eta _1(1855)$$ in $$\chi _{cJ}$$ decays

Using the ballistic approximation accretion flow model, this paper investigates the shadow and polarization images of a Kerr-like black hole surrounded by a cold dark matter halo. By numerically solving the geodesic and radiative transfer equations, we analyze the effects of the critical density $$r_c$$ , the scale radius of the dark matter halo $$r_s$$ , the spin parameter $\textit{a}$, and the observer inclination $$\theta _o$$ on the resulting images. In all cases, a bright ring structure corresponding to higher-order images is observed, accompanied by an inner region of decreased intensity. The results show that both $$r_c$$ and $$r_s$$ increase the size of the higher-order images, while the spin parameter $\textit{a}$ and inclination $$\theta _o$$ modify the image morphology, producing a crescent-shaped bright region on the left side. In the polarization maps, the linear polarization degree $$P_o$$ is significantly lower in the higher-order image region, and the polarization vectors exhibit distinct distributions inside and outside the ring. Compared with the thin disk model, the thick disk model displays notable differences in both shadow and polarization images.

Xiao-Xiong Zeng

Chen-Yu Yang

Ke-Jian He

Li-Fang Li

The impact of cold dark matter halo on black hole shadow and polarization images under thick disk illumination

We establish, for the first time, an exact correspondence between Einstein–scalar–Maxwell theory and gauged Skyrme–Maxwell–Einstein models in $$(3+1)$$ dimensions. By constructing the simplest consistent ansatz within the gauged Skyrme–Maxwell framework, we reveal a remarkable equivalence in a sector that admits nonvanishing, highly magnetized baryonic charge. This correspondence has a particularly appealing consequence: it transfers the full power of solution-generating techniques developed for electrovacuum systems – many of which naturally accommodate scalar fields – to the considerably more intricate setting of gauged Skyrme–Maxwell theory minimally coupled to General Relativity. As a result, it opens the door to a systematic and much broader exploration of exact solutions in Skyrme–Maxwell–Einstein theory and of their potential applications in cosmology and astrophysics. Notably, the resulting configurations carry nonzero baryonic charge whenever the derivative of the hadronic profile along the magnetic field lines does not vanish. As an illustrative example, we apply this new dictionary to a rotating Kerr–Newman–like spacetime dressed with a scalar field. In the corresponding Skyrme–Maxwell–Einstein solution, the quantization of the baryonic charge enforces a quantization of the Kerr rotation parameter. We derive an upper bound on the baryonic charge in terms of the integration constants of the solution and show that, in the regime of small baryonic charge, the rotation parameter depends linearly on the baryonic charge.

Chile

Fabrizio Canfora

Anibal Neira

Seung Oh

Generation of gravitating solutions with Baryonic charge from Einstein–scalar–Maxwell seeds

We study the Page curve and information paradox for Kerr AdS black hole in light of entanglement entropy by employing the recently proposed island paradigm. By incorporating the island rule, we show that the entanglement entropy of Kerr AdS black hole grows linearly at early times and declines to a constant value at late times in agreement with the well established Page curve. The novelty of this study resides in the investigation of influence of phase transitions on the page curve in two different ensembles. We find that a first order phase transition results in a sharp discontinuity in the Page curve. We study the evaporation process in different scenarios and find that in all the situations, the Page curve doesn’t violate the unitary principle of quantum mechanics.

India

Digen Das

Mozib Awal

Prabwal Phukon

Entanglement islands, Page curves and phase transitions of Kerr-AdS black holes

Perturbative expansions in quantum field theory are typically asymptotic, with large-order growth driven by instantons (factorial proliferation of diagrams) and renormalons (factorial growth from momentum integrations). In this work we compute the large-order behavior and Borel-plane singularity structure for several nontrivial truncations of Schwinger-Dyson equations, including diagram classes whose asymptotics have not, to our knowledge, been previously worked out. We recover the known chain-, rainbow-, and Hopf-series results in $\textit{ϕ}$ theory and extend the analysis to additional truncations, including the two-arm $\textit{ϕ}$ self-energy class in $\textit{d}$ = 6 and several classes in $\textit{ϕ}$ theory in $\textit{d}$ = 4. Our derivations use Schwinger-Dyson equations together with Borel transforms and a direct renormalization-group/leading-log analysis: given the same primitive integral input, this yields the relevant differential/recursion structure and makes the renormalon interpretation of the dominant Borel singularities manifest. Finally, we provide a self-contained, example-driven introduction to the Connes-Kreimer Hopf-algebraic organization of renormalization and its relation to conventional QFT notions, serving as a bridge between the combinatorial-Hopf and perturbative-QFT communities.

United States

Luen Clingerman

Matthew Schwartz

Asymptotic behavior of diagram classes