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)

Blazars are a class of active galactic nuclei, supermassive black holes located at the centres of distant galaxies characterised by strong emission across the entire electromagnetic spectrum, from radio waves to gamma rays. Their relativistic jets, closely aligned to the line of sight from Earth, are a rich and complex environment, characterised by the presence of strong magnetic fields over parsec-scale lengths. Owing to their cosmological distance from Earth, these sources serve as ideal targets to probe non-standard gamma-ray propagation. In particular, axion-like particles (ALPs) could be detected through their coupling to photons, which enables ALP-photon conversions in external magnetic fields, leading to distinct signatures in the blazars’ gamma-ray spectra. In this work, we estimate the potential of the Cherenkov Telescope Array Observatory (CTAO) to constrain the ALP parameter space by simulating observations of two bright blazars, Mrk 501 and PKS 2155−304. We obtain projected $$2\sigma $$ exclusion regions, demonstrating that CTAO will be able to consistently improve present limits thanks to its greater energy resolution and point-source sensitivity with respect to present ground-based gamma-ray telescopes. In addition to the standard statistical technique based on the likelihood ratio test, we further demonstrate the application of a new method based on machine learning classifiers, which may help in reducing the effect of systematic model-dependent uncertainties in future ALP searches.

Italy

F. Schiavone

L. Di Venere

F. Giordano

Projected sensitivity of CTAO to axion-like particles from blazars with a machine learning approach

A representation of Lattice Gauge Theories (LGT) suitable for simulations with tensor network state methods or with quantum computers requires a truncation of the Hilbert space to a finite dimensional approximation. In particular for U(1) LGTs, several such truncation schemes are known, which we compare with each other using tensor network states. We show that a functional basis obtained from single plaquette Hamiltonians – which we call plaquette state basis – outperforms the other schemes in two spatial dimensions for plaquette, ground state energy and mass gap, as it is delivering accurate results for a wide range of coupling strengths with a minimal number of basis states. We also show that this functional basis can be efficiently used in three spatial dimensions. Green’s function Monte Carlo appears to be a highly useful tool to verify tensor network states results, which deserves further investigation in the future.

Germany

Timo Jakobs

Marco Garofalo

United States

United Kingdom

Tobias Hartung

Cyprus

Karl Jansen

Paul Ludwig

Johann Ostmeyer

Switzerland

Simone Romiti

Carsten Urbach

A comprehensive stress test of truncated Hilbert space bases against Green’s function Monte Carlo in U(1) lattice Gauge theory

We investigate the dynamics of massive scalar fields around Kerr black holes in the Einstein–Maxwell–Dilaton-Axion (EMDA) theory, incorporating the effects of perfect fluid dark matter (PFDM), characterized by the dilaton parameter $$ r_2 $$ and the PFDM parameter $$ \lambda $$ . These parameters modify both the ergosphere and the effective potential experienced by the scalar field. Using the asymptotic matching method, we compute superradiant amplification factors, while quasinormal mode (QNM) frequencies are obtained via the asymptotic iteration method (AIM). Our results reveal contrasting effects: increasing $$ r_2 $$ enhances superradiance and leads to higher QNM frequencies with greater damping, whereas increasing $$ \lambda $$ suppresses superradiance and reduces QNM frequencies with weaker damping. In combined scenarios, the influence of $$ \lambda $$ is found to be dominant. These findings extend the understanding of Kerr black holes in EMDA backgrounds and highlight the stabilizing role of PFDM in such systems.

Thailand

Teparksorn Pengpan

Superradiance and quasinormal modes of massive scalar fields around Kerr black holes in Einstein–Maxwell–Dilaton-axion theory with perfect fluid dark matter

We suggest a new duality between a pair of 3d $$ \mathcal{N} $$ = 5 SCFTs, one of ABJ type and one based on the exceptional superalgebra $\textit{F}$ (4). Our main evidence for the proposed duality is the matching of the superconformal index. In addition to the intrinsic interest in dualities between strongly coupled field theories, the result can also be useful in the classification of 3d $$ \mathcal{N} $$ = 5 SCFTs.

Israel

Ki-Hong Lee

Belal Nazzal

Gabi Zafrir

A note on dualities of F(4) type 3d $$ \mathcal{N} $$ = 5 SCFTs

Renormalization is an essential technique in field-theoretic descriptions of natural phenomena, where the absence of a UV-complete description yields an abundance of divergent quantities. While the renormalization prescription has been thoroughly refined for equilibrium systems, consistently extending it to out-of-equilibrium systems is an active area of research. In this paper, we identify a mutual information-based measure of renormalizability that applies to quantum field theories both in and out of equilibrium. Specifically, we use mutual information to characterize correlations between infinitesimal shells in momentum space and show that the logarithmic derivative of mutual information with mode separation, at large mode separation, is a measure of renormalizability. We first consider Minkowski spacetime, where we introduce dynamics by performing an interaction quench, initializing the field in the free theory vacuum and then turning on the interaction. We show that the late-time mutual information relaxes to that for the interacting vacuum and the logarithmic derivative at large mode separation is negative for super-renormalizable theories, zero for renormalizable (marginal) theories, and positive for non-renormalizable theories. We then consider a conformally-coupled scalar field on the Poincaré patch of de Sitter spacetime, initializing the field in the Bunch-Davies vacuum in the asymptotic past. For different self-interactions and at any finite time, we find that the resulting mutual information has the same qualitative behavior as a function of mode separation, demonstrating that it can be used as a reliable indicator of renormalizability.

Brenden Bowen

Albert Farah

Spasen Chaykov

Nishant Agarwal

Mutual information as a measure of renormalizability

We show that certain ’t Hooft anomalies not detected by standard closed four-dimensional probes can become visible when a quantum field theory is placed on asymptotically locally Euclidean (ALE) spaces. As a concrete example, we use the Eguchi–Hanson (EH) space, whose defining features are its nontrivial second cohomology generated by the self-intersecting two-sphere and its asymptotic boundary ℝℙ , which carries torsion and thus furnishes additional cohomological data absent on conventional backgrounds. For a theory with symmetry $\textit{G}$ × $\textit{G}$ , we turn on background flux for $\textit{G}$ and probe potential anomalies by performing a global $\textit{G}$ transformation; the resulting anomaly is captured by a five-dimensional mapping torus. The anomaly receives contributions from the four-dimensional characteristic classes on EH space as well as from the $\textit{η}$-invariant associated with the ℝℙ boundary. The anomaly detected in this way imposes additional constraints on asymptotically free gauge theories with fixed trivial asymptotic boundary conditions. In particular, infrared composite spectra that match anomalies on standard closed manifolds may nevertheless fail to reproduce the EH anomaly, and thus cannot by themselves furnish a complete symmetry-preserving infrared realization.

Mohamed Anber

Anomalies on ALE spaces and phases of gauge theory

Some effects induced by SMEFT operators at one loop have attracted a lot of attention in recent years, in particular, the renormalization of divergences by physical operators in single insertions of dimension-6 operators. Important non-logarithmically enhanced contributions must also be calculated. We discuss dimensional regularization in the Breitenlohner-Maison-’t Hooft-Veltman scheme. The goal here is to calculate in this scheme quantum effects in chiral theories at one loop. We determine the finite counterterms at one loop that reestablish the Slavnov-Taylor identities, which follow from gauge symmetries. These counterterms are necessary due to the presence of evanescent symmetry-breaking terms in the classical Lagrangian needed to regularize fermion propagators. We consider a technique that allows an easier calculation of such finite effects, relying on the identification of ($\textit{D}$ − 4)$\textit{/}$($\textit{D}$ − 4) terms of one-loop amplitudes with an external ghost leg. We focus on dimension-6 four-fermion operators, identifying all finite counterterms in the Breitenlohner-Maison-’t Hooft-Veltman scheme at one loop, and as expected find no obstructions to the Slavnov-Taylor identities that cannot be cured by finite counterterms. This represents one step towards moving to higher order calculations.

Spain

Sergio Ferrando Solera

Sebastian Jäger

Luiz Vale Silva

Symmetry-restoring finite counterterms of SMEFT four-fermion operator insertions at one loop