Pulsars are observed to emit bright and spatially extended gamma-ray emission at multi-TeV energies. These so-called “TeV halos” are now understood to be a nearly universal feature of middle-aged pulsars. However, many of the key physical processes that govern these systems, particularly those affecting particle diffusion, remain poorly constrained. We aim to evaluate the ability of the Cherenkov Telescope Array (CTA) to probe the physical properties of TeV halos, with a focus on the nearby and well-studied case of the Geminga pulsar. We simulate gamma-ray emission from various TeV halo models, incorporating different assumptions for the injected electron spectrum, spin-down evolution, and energy-dependent diffusion. These models are then used to forecast CTA’s sensitivity to spectral and spatial differences, based on realistic mock observations and instrument response simulations. We find that CTA will be able to distinguish between a wide range of TeV halo models that are currently consistent with existing data. In particular, CTA observations can constrain the normalization, energy dependence, and spatial extent of the diffusion coefficient surrounding Geminga, as well as the spectral shape of the injected electron population.

United States

D. Hooper

E. Pinetti

A. Sokolenko

Unraveling TeV halos with the Cherenkov Telescope Array

Scientific AI is rapidly transforming fundamental physics research and challenging defining aspects of the fundamental physics methodology. We discuss opportunities and dangers of this transformation and find exciting benefits from a close interaction between AI and fundamental physics, provided that we remain aware of the scientific methodologies of the respective fields. For fundamental physics, we discuss two such aspects: statistical validation and a generalizing theory description, both with the goal of discovering new physics in vast datasets.

Germany

Michael Krämer

Tilman Plehn

Machine learning is good for physics—and vice versa

Anomalies in the non-leptonic $$\bar{B}^0\rightarrow D^{(*)+}K^{(*)-}$$ and $$\bar{B}^0_s\rightarrow D^{(*)+}_s\pi ^-$$ decays may be an indication of physics beyond the Standard Model, but the large deviations require strongly coupled new physics that should be visible at colliders. We explore three new directions that could lead to viable new physics models, performing a detailed collider study to examine the possible weakening of previously known constraints on additional $$SU(2)_L$$ doublets. Our results show that, despite the difficulty of probing $$t\bar{t}$$ final states, increasing the branching ratio to this decay mode does not significantly weaken the bounds on weak doublet scalars, as additionally existing charged Higgs searches are equally strong. Beyond this, we analyse a potentially large breakdown of QCD factorisation by including large-power corrections to $\textit{B}$ decays, and the effect of diluting collider searches with multi-scalar extensions. We find that these typical model-building routes for constructing a viable scenario remain constrained by collider measurements, indicating that these non-leptonic anomalies remain among the most puzzling discrepancies from the SM.

United Kingdom

Jack Araz

Christoph Englert

Matthew Kirk

Gilberto Tetlalmatzi-Xolocotzi

New insights into the $$b\rightarrow c \bar{u}q$$ puzzle through Top–Bottom synergies

Over the last decade, non-relativistic theories have attracted considerable attention. In general, such theories can be obtained by contracting relativistic parent theories. In this work, we discuss features of non-relativistic supersymmetric field theories from both the Galilean and Carrollian points of view that may be useful for constructing electric and magnetic non-relativistic theories.

Türkiye

Osman Ergec

Aspects of non-relativistic supersymmetric theories

We solve the radical-square reflection residual of the symmetric elliptic free-fermion eight-vertex model in a minimal four-dimensional local coefficient algebra. Two parity-odd tangent channels generate an ordered product in the square of the radical, and the reflection equation fixes its parity-even completion within the trace-fixed sector whose radical-square term starts at order <italic>u</italic> <sup>2</sup>. The resulting regular boundary object enters a double-row transfer construction. Its scalar quotient yields the open anisotropic XY Hamiltonian with diagonal boundary fields, while the full transfer object retains the non-semisimple boundary channels. Finite-chain audits through <math altimg='si1.svg'><mrow><mi>N</mi><mo linebreak='goodbreak'>=</mo><mn>12</mn></mrow></math> accompany the analytic construction.

China

Ze Tao

Hao Yan

Fujun Liu

Exact open anisotropic XY Hamiltonian from a non-semisimple boundary completion

We investigate <italic>X</italic>(6900) as a hadronic realization of a gluonic portal between a dark sector and QCD. The analysis is updated using the 2026 CMS observation of a family of all-charm structures and a recent combined LHCb&#8211;ATLAS&#8211;CMS analysis of the di- <italic>J</italic>/ <italic>&#968;</italic> spectrum. The CMS angular analysis favors <math altimg='si19.svg'><mrow><msup><mi>J</mi><mrow><mi>P</mi><mi>C</mi></mrow></msup><mo linebreak='goodbreak'>=</mo><msup><mn>2</mn><mrow><mo>+</mo><mo>+</mo></mrow></msup></mrow></math>, motivating a spin-two mediator rather than the scalar ansatz used in earlier versions of this study. The combined analysis also demonstrates that the extracted <italic>X</italic>(6900) mass and width are significantly model dependent because of interference. We therefore use <math altimg='si20.svg'><mrow><msub><mi>M</mi><mi>X</mi></msub><mo linebreak='goodbreak'>=</mo><mn>6.919</mn><mspace width='0.33em' /><mtext>GeV</mtext></mrow></math> and <math altimg='si21.svg'><mrow><msub><mstyle mathvariant='normal'><mi>&#915;</mi></mstyle><mi>X</mi></msub><mo linebreak='goodbreak'>=</mo><mn>70.3</mn><mspace width='0.33em' /><mtext>MeV</mtext></mrow></math> as a reference benchmark, corresponding to the narrow-width, weak-interference Model I of the combined analysis, while treating the spread among interference models as a systematic theoretical uncertainty. The interaction is <display><formula id='ueq0001'><math altimg='si22.svg'><mrow><msub><mi mathvariant='script'>L</mi><mrow><mrow><mi mathvariant='normal'>i</mi></mrow><mi>n</mi><mi>t</mi></mrow></msub><mo linebreak='goodbreak'>=</mo><mo>&#8722;</mo><mfrac><msub><mi>c</mi><mi>&#967;</mi></msub><mstyle mathvariant='normal'><mi>&#923;</mi></mstyle></mfrac><msub><mi>X</mi><mrow><mi>&#956;</mi><mi>&#957;</mi></mrow></msub><msubsup><mi>T</mi><mi>&#967;</mi><mrow><mi>&#956;</mi><mi>&#957;</mi></mrow></msubsup><mo linebreak='goodbreak'>&#8722;</mo><mfrac><msub><mi>c</mi><mi>g</mi></msub><mstyle mathvariant='normal'><mi>&#923;</mi></mstyle></mfrac><msub><mi>X</mi><mrow><mi>&#956;</mi><mi>&#957;</mi></mrow></msub><msubsup><mi>T</mi><mi>g</mi><mrow><mi>&#956;</mi><mi>&#957;</mi></mrow></msubsup><mo>.</mo></mrow></math></formula></display>Using the standard spin-two normalization, <display><formula id='ueq0002'><math altimg='si23.svg'><mrow><mstyle mathvariant='normal'><mi>&#915;</mi></mstyle><mrow><mo>(</mo><mi>X</mi><mo>&#8594;</mo><mi>g</mi><mi>g</mi><mo>)</mo></mrow><mo linebreak='goodbreak'>=</mo><mfrac><mrow><msubsup><mi>c</mi><mi>g</mi><mn>2</mn></msubsup><msubsup><mi>M</mi><mi>X</mi><mn>3</mn></msubsup></mrow><mrow><mn>10</mn><mi>&#960;</mi><msup><mstyle mathvariant='normal'><mi>&#923;</mi></mstyle><mn>2</mn></msup></mrow></mfrac><mo>,</mo></mrow></math></formula></display>and the gluonic gravitational form factor <italic>A<inf>g</inf></italic>(0), the leading spin-independent nucleon cross section is <display><formula id='ueq0003'><math altimg='si24.svg'><mrow><msubsup><mi>&#963;</mi><mrow><mi>&#967;</mi><mi>N</mi></mrow><mrow><mrow><mi mathvariant='normal'>S</mi></mrow><mi>I</mi></mrow></msubsup><mo linebreak='goodbreak'>=</mo><mfrac><mrow><msubsup><mi>&#956;</mi><mrow><mi>&#967;</mi><mi>N</mi></mrow><mn>2</mn></msubsup><msubsup><mi>m</mi><mi>&#967;</mi><mn>2</mn></msubsup><msubsup><mi>m</mi><mi>N</mi><mn>2</mn></msubsup></mrow><mi>&#960;</mi></mfrac><msup><mrow><mo stretchy='true'>(</mo><mfrac><mrow><msub><mi>c</mi><mi>&#967;</mi></msub><msub><mi>c</mi><mi>g</mi></msub></mrow><mrow><msup><mstyle mathvariant='normal'><mi>&#923;</mi></mstyle><mn>2</mn></msup><msubsup><mi>M</mi><mi>X</mi><mn>2</mn></msubsup></mrow></mfrac><mo stretchy='true'>)</mo></mrow><mn>2</mn></msup><msub><mi>A</mi><mi>g</mi></msub><msup><mrow><mo>(</mo><mn>0</mn><mo>)</mo></mrow><mn>2</mn></msup><mo>.</mo></mrow></math></formula></display>For <math altimg='si2.svg'><mrow><msub><mi>A</mi><mi>g</mi></msub><mrow><mo>(</mo><mn>0</mn><mo>)</mo></mrow><mo linebreak='goodbreak'>=</mo><mn>0.42</mn></mrow></math>, <math altimg='si8.svg'><mrow><msub><mi>B</mi><mrow><mi>g</mi><mi>g</mi></mrow></msub><mo linebreak='goodbreak'>=</mo><mn>0.10</mn></mrow></math>, and <math altimg='si25.svg'><mrow><msub><mi>m</mi><mi>&#967;</mi></msub><mo linebreak='goodbreak'>=</mo><mn>100</mn><mspace width='0.33em' /><mtext>GeV</mtext></mrow></math>, the benchmark reference-scale estimate implies <math altimg='si26.svg'><mrow><msub><mi>c</mi><mi>&#967;</mi></msub><mo linebreak='goodbreak'>/</mo><mstyle mathvariant='normal'><mi>&#923;</mi></mstyle><mo>&#8818;</mo><mn>1.87</mn><mo linebreak='goodbreak'>&#215;</mo><msup><mn>10</mn><mrow><mo>&#8722;</mo><mn>8</mn></mrow></msup><mspace width='0.33em' /><msup><mrow><mtext>GeV</mtext></mrow><mrow><mo>&#8722;</mo><mn>1</mn></mrow></msup></mrow></math> when the 90% C.L. XENONnT reference scale is imposed. The annihilation channel <math altimg='si4.svg'><mrow><mi>&#967;</mi><mover accent='true'><mi>&#967;</mi><mo>&#175;</mo></mover><mo>&#8594;</mo><msup><mi>X</mi><mo>*</mo></msup><mo>&#8594;</mo><mi>g</mi><mi>g</mi></mrow></math> is <italic>p</italic>-wave suppressed and resonantly enhanced at <math altimg='si27.svg'><mrow><msub><mi>m</mi><mi>&#967;</mi></msub><mo>&#8771;</mo><msub><mi>M</mi><mi>X</mi></msub><mo linebreak='goodbreak'>/</mo><mn>2</mn><mo linebreak='goodbreak'>=</mo><mn>3.46</mn><mspace width='0.33em' /><mtext>GeV</mtext></mrow></math>. We show that the most important phenomenological uncertainty is no longer the existence of <italic>X</italic>(6900), which is now highly significant, but the interpretation of its line shape and hence the extraction of its mass, width, and gluonic coupling. We argue that a small set of numerical figures is essential for a publication-quality presentation: the direct-detection exclusion plane, the resonance line shape, and the resonant annihilation line shape.

Iran

Majid Monemzadeh

<italic>X</italic>(6900) as a hadronic mediator of a gluonic dark-matter portal

We investigate the gravitational deflection of charged massive particles by a charged galactic wormhole supported by the Sofue dark matter density profile [56], <math altimg='si2.svg'><mrow><mi>&#961;</mi><mrow><mo>(</mo><mi>r</mi><mo>)</mo></mrow><mo linebreak='goodbreak'>=</mo><msub><mi>&#961;</mi><mn>0</mn></msub><msup><mi>e</mi><mrow><mo>&#8722;</mo><mi>r</mi><mo>/</mo><msub><mi>r</mi><mn>0</mn></msub></mrow></msup><mo>,</mo></mrow></math> where <italic>&#961;</italic> <inf>0</inf> and <italic>r</italic> <inf>0</inf> denote the central dark matter density and the characteristic scale radius, respectively. This phenomenological profile models the dark matter distribution in galactic halos and acts as the matter source sustaining the wormhole geometry. Extending our previous investigation of light rays and neutral massive particles in this spacetime [57], we study the combined effects of gravitational and electromagnetic interactions on the motion of charged massive particles. The deflection angle is computed independently using the Rindler&#8211;Ishak method based on the Jacobi metric and the Gauss&#8211;Bonnet theorem, enabling a systematic comparison between the two approaches. We find that the predictions of the two methods become nearly indistinguishable in the relativistic regime, whereas the differences at lower velocities arise from the velocity-dependent correction terms proportional to <math altimg='si3.svg'><mrow><mo>(</mo><mn>1</mn><mo linebreak='goodbreak'>&#8722;</mo><msup><mi>v</mi><mn>2</mn></msup><mo>)</mo></mrow></math> in the trajectory equation. We further perform backward relativistic ray tracing of optically thin accretion flows around the charged galactic wormhole to investigate its shadow and photon-ring structure. Although the shadow remains circular because of the spacetime&#8217;s spherical symmetry, its radius, photon-ring structure, and intensity distribution exhibit a nontrivial dependence on the wormhole charge, providing potential observational signatures of charged galactic wormholes. These results provide new insights into the interplay between gravitational and electromagnetic interactions in charged wormhole spacetimes and their observational manifestations.

India

Md Khalid Hossain

Humaun Kabir Laskar

Farook Rahaman

Aritra Sanyal

Charged galactic wormholes: Shadow imaging, accretion disks, and charged-particle deflection

Two Higgs doublets models with a scalar potential that breaks electroweak symmetry spontaneously can have either one or two local minima. While potentials with one minimum can have a decoupling regime where all the new scalars are heavy, we show that, for potentials with <italic>two</italic> local minima, the masses of all the scalars are bounded if the dimensionless quartic couplings obey perturbativity constraints.

Spain

José M. Camacho

Italy

Carlos Miró

Miguel Nebot

Tomás Tobarra

On vacua and bounded masses in the general 2HDM

A stationary surface response is formulated for an isolated, settled disk galaxy as a possible endpoint of deformation memory. The response is described by a scalar field coupled to the projected baryonic density, with a positive quadratic Hamiltonian and a finite range Green function constructed from the modified Bessel function <italic>K</italic> <inf>0</inf>. SPARC selects the long range regime, where the additional circular support follows the enclosed projected mass. Its normalization is fixed by the baryonic Tully&#8211;Fisher relation through a single acceleration scale. For 153 primary SPARC galaxies, the model gives a median relative rotation curve residual of 0.166, compared with 0.159 for the radial acceleration relation and 0.081 for NFW fits with two parameters for each galaxy. The inferred acceleration scale agrees with the canonical galactic value. Bootstrap resampling places the response and radial acceleration relation within the same population interval. Their predictions separate through their dependences on baryonic concentration, source mass, surface brightness, and gas fraction. These relations provide observational tests of an enclosed mass response as a description of galactic dynamics.

Kazakhstan

Daulet Berkimbayev

A deformation memory model for galactic rotation curves

In this paper, we investigate the Krylov complexity of the massless scalar field in the massive Bañados-Teitelboim-Zanelli (BTZ) black hole with quantum fluctuation. This fluctuation is considered to be triggered by the Hawking radiation, which indeed influences the behavior of the time evolution of Krylov complexity. Our results show that Lanczos coefficients <italic>b<inf>n</inf></italic> exhibit a black hole mass <italic>M</italic>-dependent staggering, <math altimg='si7.svg'><mrow><mstyle mathvariant='normal'><mi>&#916;</mi></mstyle><mover><mrow><msub><mi>b</mi><mi>N</mi></msub></mrow><mo stretchy='true'>&#8254;</mo></mover><mo>&#8764;</mo><mi>M</mi></mrow></math>, inducing oscillatory complexity dynamics that intensify with lower mass black holes. Moreover, the graviton mass <italic>m</italic> is found to suppress the oscillations but accelerate the late-time exponential growth <math altimg='si8.svg'><mrow><mi>K</mi><mrow><mo>(</mo><mi>t</mi><mo>)</mo></mrow><mo>&#8764;</mo><msup><mi>e</mi><mrow><msub><mi>&#955;</mi><mi>K</mi></msub><mi>t</mi></mrow></msup></mrow></math>. This study indicates that the Krylov complexity could be a sensitive probe to distinguish massless and massive gravity via operator growth signatures.

Yu-Ting Zhou

Xiao-Mei Kuang

Krylov complexity of a massless scalar field in massive BTZ black hole with quantum fluctuation