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)

We present a model of the dark sector involving Dirac fermion dark matter, with axial coupling to a dark photon which provides a portal to Standard Model particles. In the nonrelativistic limit, this implies that the dominant effective operator relevant to direct detection is <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="script">O</mi><mn>8</mn></msub></math>. The resulting event rate for direct detection is suppressed by either the dark matter velocity or the momentum transfer. In this scenario there are much wider regions of the dark parameter space that are consistent with all of the existing constraints associated with thermal relic density, direct detection, and collider searches.

Australia

X.G. Wang

A.W. Thomas

Relaxed constraints for dark matter with axial coupling to a dark photon

We study interacting scalar field theories in which different fields propagate with inequivalent spatial kinetic tensors, corresponding to different sound speeds in different directions. We derive the exact elastic two-body unitarity relation and show that the phase space defines a positive kernel on the sphere, so that the scattering amplitude acts as an operator in angular-momentum space. The corresponding unitarity bounds constrain the eigenvalues of the phase-space-rescaled amplitude. In the weak-anisotropy regime, we obtain the leading correction explicitly and show that it induces <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>s</mi><mo>−</mo><mi>d</mi></math> mixing. For a two-scalar quartic model, we verify the anisotropic optical theorem at one loop and derive coupled channel elastic unitarity bounds. We also compute the local one-loop effective potential and analyze the corresponding one-loop renormalization-group structure. In the classically scale-invariant limit, the Gildener-Weinberg flat direction is unchanged, whereas anisotropy modifies the radiatively generated scalon mass. In the isotropic but unequal-velocity limit, several results become analytic and the RG flow exhibits an additional invariant ray.

Russia

Dmitry S. Ageev

Yulia A. Ageeva

Disparity in sound speeds: Implications for elastic unitarity and the effective potential in quantum field theory

The recent observation of a family of fully charm tetraquark states by the LHCb, ATLAS, and CMS Collaborations suggests the possible existence of fully heavy dibaryons. In this work, we investigate the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Ω</mi><mrow><mi>c</mi><mi>c</mi><mi>c</mi></mrow></msub><msub><mi mathvariant="normal">Ω</mi><mrow><mi>c</mi><mi>c</mi><mi>c</mi></mrow></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Ω</mi><mrow><mi>b</mi><mi>b</mi><mi>b</mi></mrow></msub><msub><mi mathvariant="normal">Ω</mi><mrow><mi>b</mi><mi>b</mi><mi>b</mi></mrow></msub></math> dibaryons in both the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mmultiscripts><mrow><msub><mrow><mi>S</mi></mrow><mrow><mn>0</mn></mrow></msub></mrow><mprescripts></mprescripts><none></none><mrow><mn>1</mn></mrow></mmultiscripts></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mmultiscripts><mrow><msub><mrow><mi>S</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow><mprescripts></mprescripts><none></none><mrow><mn>5</mn></mrow></mmultiscripts></mrow></math> channels using the method of QCD sum rules. We employ the iterative dispersion relation (IDR) method to efficiently compute the massive five-loop banana diagrams that appear in these systems, and properly address the tricky small-circle divergence problem in the nonperturbative terms. Our analyses reveal that for both charm and bottom systems, the scalar dibaryon lies lower than its tensor counterpart. In the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mover accent="true"><mi>MS</mi><mo stretchy="true">¯</mo></mover></math> scheme, the mass of the scalar <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Ω</mi><mrow><mi>c</mi><mi>c</mi><mi>c</mi></mrow></msub><msub><mi mathvariant="normal">Ω</mi><mrow><mi>c</mi><mi>c</mi><mi>c</mi></mrow></msub></math> dibaryon is found to be slightly above the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2</mn><msub><mi mathvariant="normal">Ω</mi><mrow><mi>c</mi><mi>c</mi><mi>c</mi></mrow></msub></math> mass threshold, while the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Ω</mi><mrow><mi>b</mi><mi>b</mi><mi>b</mi></mrow></msub><msub><mi mathvariant="normal">Ω</mi><mrow><mi>b</mi><mi>b</mi><mi>b</mi></mrow></msub></math> systems may form bound states. However, they are predicted to be much heavier in the on-shell scheme.

Xu-Liang Chen

Jin-Peng Zhang

Zi-Xi Ou-Yang

Wei Chen

Jia-Jun Wu

Study of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Ω</mi><mrow><mi>c</mi><mi>c</mi><mi>c</mi></mrow></msub><msub><mi mathvariant="normal">Ω</mi><mrow><mi>c</mi><mi>c</mi><mi>c</mi></mrow></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Ω</mi><mrow><mi>b</mi><mi>b</mi><mi>b</mi></mrow></msub><msub><mi mathvariant="normal">Ω</mi><mrow><mi>b</mi><mi>b</mi><mi>b</mi></mrow></msub></math> dibaryons in QCD sum rules

We develop a basis-covariant one-loop renormalization framework for two interacting real scalars in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi><mo>=</mo><mn>4</mn><mo>−</mo><mi>ε</mi></math> with the most general parity even two-derivative Lorentz-violating quadratic form, allowing anisotropic spatial gradients and direction-dependent kinetic mixing, together with general cubic and quartic interactions and the relevant lower-dimensional operators forming a renormalization group complete set of operators at one-loop. In dimensional regularization with minimal subtraction we compute the full set of one-loop UV divergences and obtain closed beta functions for quartic and cubic couplings, masses, and linear couplings. The pole coefficients admit a universal spectral representation as angular averages over the direction-dependent eigenvalues and projectors of the UV kinetic matrix; all anisotropy dependence enters through a single universal kernel admitting two-particle phase-space interpretation. We classify fixed points and fixed manifolds and show, in particular, that anisotropy restricts the existence of the coupled Wilson-Fisher-type fixed point. When the cross-gradients are turned on, the coefficients in beta functions are governed by six phase-space weights admitting interpretation in terms of encoding “populations” and “coherences” of the UV normal modes.

One-loop renormalization of anisotropic two-scalar quantum field theories

We summarize the formalism for calculating the exclusive dijet production in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>e</mi><mi>p</mi><mo stretchy="false">→</mo><msup><mi>e</mi><mo>′</mo></msup><mi>j</mi><mi>j</mi><mi>p</mi></math> in collinear QCD factorization, using generalized parton distributions as the soft hadronic input modeled in the double distribution approach. We include all leading-order contributions coming from light sea and valence quark exchanges, and gluon exchanges for both light quark-antiquark (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>q</mi><mover accent="true"><mi>q</mi><mo stretchy="false">¯</mo></mover></math>) production and also the heavy <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>c</mi><mover accent="true"><mi>c</mi><mo stretchy="false">¯</mo></mover></math> final state. We present results for several differential distributions for the cross section evaluated over a broad region of phase space, covering a wide range of inelasticity and photon virtuality. The gluon and sea contributions exhibit similar shapes, whereas the valence contribution, though relatively small, shows a markedly different behavior. The latter becomes particularly noticeable at large <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>x</mi><mi mathvariant="double-struck">P</mi></msub></math>, a kinematic region not explored at HERA, but potentially accessible in future measurements at the Electron Ion Collider. This requires further feasibility studies. We also present the azimuthal angle modulation between the leptonic and the outgoing dijet planes for the general case, as well as for the ZEUS kinematic region where we see reasonable agreement with the data for diffractive deep inelastic scattering parameter <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>β</mi><mo>≳</mo><mn>0.4</mn></math>.

Poland

Trambak Jyoti Chall

Marta Łuszczak

Wolfgang Schäfer

Antoni Szczurek

Probing GPDs in exclusive electroproduction of dijets

We investigate a modified affine Toda model coupled to matter (ATM), which includes a scalar self-interacting potential and demonstrate that its first-order integrodifferential structure, preserving a deformed Noether-topological current correspondence, provides a consistent framework for fermion-soliton interactions. In this formulation, the fermion-soliton energy is proportional to the soliton’s topological charge. We evaluate the renormalized energy functional, incorporating one-loop quantum corrections, and perform a variational minimization to determine the configuration that extremizes the functional. The fermionic backreaction and the self-interacting scalar critically shape the fermion-kink energy, the in-gap bound-state spectrum, and the fermionic vacuum-polarization energy, yielding well-defined stability minima of the total energy as functions of the fermion and scalar masses and coupling parameters, in the semiclassical approximation. A key result is that the Heun-equation formalism is necessary to construct nonzero-energy bound and scattering states: unlike the tau-function method, which captures only the zero mode, the Heun approach encodes the full scattering data through local solution matching conditions. These results refine the spectral analysis of deformed integrable models. The stability of soliton-fermion configurations has direct implications for topologically protected states in quantum information and condensed-matter systems.

Brazil

Harold Blas

Hirota-tau- and Heun-function framework for Dirac vacuum polarization and quantum stabilization of kinks

We study the Joule–Thomson expansion and extended thermodynamics of a modified black hole characterised by the parameters $$\alpha $$ , $$\beta $$ , and $$\sigma $$ . Analysis of the Hawking temperature, Joule–Thomson coefficient, inversion curves, and isenthalpic trajectories shows that these parameters significantly modify the heating–cooling behaviour and thermal stability of the system. The deformation parameter $$\alpha $$ and control parameter $$\beta $$ shift the temperature minimum, enlarge the cooling region, and raise the inversion temperature, while $$\sigma $$ produces a weaker but consistent influence. The heat-engine analysis reveals that $$\alpha $$ enhances efficiency, whereas higher $$\beta $$ and $$\sigma $$ reduce it. Overall, the results demonstrate that geometric deformation and quintessence jointly govern the unified thermodynamic structure of the black hole.

Azerbaijan

India

Dhruba Gogoi

Ronit Karmakar

Jyatsnasree Bora

Pohar Buragohain

Chandika Gogoi

Joule–Thomson effect and efficiency of deformed AdS–Schwarzschild black hole in presence of quintessence