The beyond-the-standard-model scenario presented in this work is motivated by the observations of neutrino masses, the anomalous magnetic moments of the electron and muon, and dark matter in the Universe. We explain these observations by extending the standard model with two generations of vector-like fermions and an inert scalar doublet, all of which are odd under a $Z_2$ symmetry. The light neutrino masses and mixings are generated radiatively while maintaining consistency with bounds on lepton flavor violation. Loop diagrams featuring the same fields also explain the anomalous magnetic moments. Similarly, the correct dark matter relic abundance is reproduced without conflicting with direct detection constraints, or those from big bang nucleosynthesis or cosmic microwave background observations. Finally, prospective signatures at the LHC are discussed.

India

Vandana Sahdev

Neutrino masses, anomalous magnetic moments and dark matter with vector-like fermions and an inert scalar doublet * V.S. acknowledges the support from research grant no. CRG/2018/004889 of the SERB, India; T.R. Seshadri for providing resources during the initial stages of the work; and Brajesh Choudhary for providing access to computers bought under the aegis of Grant No. SR-MF/PS-0212014-DUB (G) of the DST (India)

We present an investigation of the $ K^*(1680) $ state in its strong decays into two-body final states within the flux-tube model and quark pair creation model. Since charge conjugation parity is not conserved in the strange sector, the conventional $ q\bar{q} $ states with $ J^{P(C)}=1^{-(-)} $ can mix with the lowest hybrid states with $ J^{P(C)}=1^{-(+)} $ . Our analysis of the $ K^*(1680) $ two-body strong decays indicates that the decay pattern of $ K^*(1680) $ cannot be explained by the conventional $ q\bar{q} $ scenario. Moreover, there is strong evidence for the $ q\bar{q} $ -hybrid mixing mechanism in the strange sector. The phenomenological consequences of such mixing are also discussed. Our study can provide guidance for future searches for hybrid multiplets in experiments at BESIII, LHCb, and Belle II.

China

Samee Ullah

Ye Cao

Ming-Xiao Duan

Hai-Bing Fu

Qiang Zhao

Nature of ${K^*(1680)}$ and ${q\bar{q}}$ -hybrid mixing as the $\textit{SU}$(3) partner of ${\eta_{1}(1855)}$ in the strange sector * Supported in part by the National Natural Science Foundation of China (12235018, 12265010, 12505098), and the Project of Guizhou Provincial Department of Science and Technology (MS[2025]219, CXTD[2025]030, ZD[2026]168, QN[2025]178), and the project of Guizhou Normal University (GZNUD[2025]05)

We investigate the impact of a non-gravitational dark sector interaction on the growth of matter density perturbations within both the interacting $\textit{w}$CDM and the dynamical Chevallier–Polarski–Linder (CPL) scenarios. For $\textit{w}$CDM model, we develop a parameterization for the growth rate based on a second-order approximation for the growth index $$\gamma $$ that explicitly includes the coupling constant $$\alpha $$ . Our analysis reveals a theoretical degeneracy: the coupling induces a correction $$\Delta \gamma \simeq 1.1\alpha $$ in both models, allowing an interacting dark energy model to mimic the growth index predicted by certain modified gravity theories. Then, we confront the models with the latest multi-probe observations, including the Pantheon+ sample of Type Ia supernovae, Baryon Acoustic Oscillation (BAO) data from the Sloan Digital Sky Survey (SDSS) and the second data release (DR2) of the Dark Energy Spectroscopic Instrument (DESI), Cosmic Microwave Background (CMB) measurements, Hubble parameter $\textit{H}$($\textit{z}$) data, and redshift-space distortion (RSD) measurements. Our analysis finds that the coupling constant is consistent with zero at approximately the $$3\sigma $$ and $$2\sigma $$ confidence levels for $\textit{w}$CDM and CPL models, respectively, showing no definitive statistical evidence for a departure from the standard $$\Lambda $$ CDM cosmology. The observational constraints strongly disfavor the region of parameter space where interacting dark energy can mimic modified gravity, restricting the growth index to a common approximate interval of $$0.53 \lesssim \gamma \lesssim 0.60$$ for both models. This reinforces the growth index as a robust diagnostic for distinguishing between a non-minimal interaction in the dark sector and a genuine modification of gravity with current data.

Fan Yang

Rongrong Zhai

Xiangyun Fu

Bing Xu

Kaiwen Liu

Chikun Ding

Yang Huang

Impact of interacting dark energy on the growth of matter density perturbations: observational constraints from DESI and multi-probe data

We study the confining flux tube in the reconfined phase of trace deformed SU(2) Yang-Mills theory in (2+1) dimensions. Using lattice simulations above the standard deconfinement temperature, we analyze Polyakov-loop correlators and extract the ground state energy of the effective string. We show that the usual Nambu-Gotō effective string description, including its standard higher-order corrections, fails to reproduce the data as the trace deformation is increased. Remarkably, deep in the reconfined regime the results are instead accurately described by the Polchinski-Yang rigid-string solution, corresponding to an effective string dominated by an extrinsic-curvature term. We further investigate the transverse profile of the chromo-electric flux tube and find significant deviations from the standard Yang-Mills behavior, including a substantial modification of the intrinsic width. Finally, we present an exploratory study of the phase diagram, finding evidence for a transition from a continuous to a first order reconfinement line as the deformation parameter increases. These results suggest that the reconfined phase realizes a qualitatively different effective-string regime from ordinary confinement.

Italy

Claudio Bonati

Michele Caselle

Germany

Alessio Negro

Dario Panfalone

Lorenzo Verzichelli

Confining flux tube in the trace deformed (2+1) dimensional SU(2) gauge theory

We study a dark photon dark matter scenario associated with a gauged <italic>U</italic>(1) <inf><italic>X</italic></inf> symmetry, stabilized by a dark parity that forbids kinetic mixing with the Standard Model. The leading interactions between the dark photon dark matter and the Standard Model arise from dimension-six Higgs-portal operators. In previous work, we found that for the parity-violating operator, the dark matter annihilation process is <italic>p</italic>-wave suppressed, naturally evading stringent direct-detection constraints while reproducing the observed relic abundance through thermal freeze-out. For a cutoff scale of 1&#8201;TeV, a dark matter mass of around 400&#8201;GeV is favored to realize the observed relic abundance. This scenario predicts cosmic-ray signals, in particular in the <math altimg='si15.svg'><mrow><msup><mi>W</mi><mo>+</mo></msup><msup><mi>W</mi><mo>&#8722;</mo></msup></mrow></math> channel, which can be targeted by indirect-detection experiments. Recently, a halo-like gamma-ray excess has been reported by Totani. Assuming a Navarro&#8211;Frenk&#8211;White <math altimg='si16.svg'><mrow><mo>&#8722;</mo><msup><mi>&#961;</mi><mn>2</mn></msup></mrow></math> morphology for the dark matter distribution, a dark matter mass of 420&#8201;GeV is favored for the <math altimg='si15.svg'><mrow><msup><mi>W</mi><mo>+</mo></msup><msup><mi>W</mi><mo>&#8722;</mo></msup></mrow></math> final state. Motivated by this excess, we consider the present dark photon dark matter framework augmented by a CP-even sub-GeV scalar mediator, which couples to the dark photon mass operator in order to enhance the present-day annihilation rate in the Galactic halo while inducing only an <math altimg='si17.svg'><mrow><mi mathvariant='script'>O</mi><mo>(</mo><mn>1</mn><mo>)</mo></mrow></math> correction at freeze-out. The exchange of this scalar induces a long-range attractive force, leading to Sommerfeld enhancement of the annihilation rate. The enhancement is saturating in dwarf spheroidal galaxies and the annihilation rate is dropping as <italic>p</italic>-wave remaining consistent with constraints from dwarf galaxies and cosmology.

Japan

Kimiko Yamashita

Higgs-portal spin-1 dark matter with parity-violating interaction for a galactic halo gamma ray excess

Five-dimensional $$ \mathcal{N} $$ = 1 superconformal field theories admit a rich variety of generalised global symmetries, including higher-form and 2-group symmetries and their ’t Hooft anomalies. We show that this data can be extracted directly from the blow-up equations governing the instanton partition functions of such theories on the Ω-background. The central object is the classical prefactor exp(−$\textit{V}$ ) weighting each magnetic flux on the blown-up geometry: evaluated on a background for the electric 1-form symmetry, the fractional parts of its exponents encode the cubic self-anomaly of the 1-form symmetry and its mixed anomalies with the instanton, flavour, gravitational, and SU(2) symmetries. Combined with the faithful continuous global symmetry of the ultraviolet fixed point, determined from the superconformal index, the same data decides whether the theory possesses a 2-group symmetry or a mixed ’t Hooft anomaly. We illustrate the method in gauge theories, including SU(4) and USp(4) with antisymmetric hypermultiplets and Spin(7) and Spin(8) with vector hypermultiplets, as well as in several families of non-Lagrangian theories. New results include the effective prepotentials of the $\textit{B}$ and $$ {B}_N^{\left(1,2,3\right)} $$ families, the cubic 1-form anomalies of the rank-two theories $$ {\mathbb{P}}^2\cup {\mathbbm{F}}_3 $$ and $$ {\mathbb{P}}^2\cup {\mathbbm{F}}_6 $$ , and several mixed 1-form–flavour and 1-form–SU(2) anomalies.

William Harding

Thailand

Noppadol Mekareeya

Generalised global symmetries in 5d $$ \mathcal{N} $$ = 1 theories from the blow-up equations

We study the non-equilibrium dynamics, thermalisation and attractor behaviour of charm quarks in a longitudinally expanding Quark–Gluon Plasma within the Relativistic Boltzmann Transport approach in 1+1D Bjorken expansion. Considering both a strong AdS/CFT coupling scenario with constant <math altimg='si2.svg'><mrow><mn>2</mn><mi>&#960;</mi><mi>T</mi><msub><mi>D</mi><mi>s</mi></msub><mo linebreak='goodbreak'>=</mo><mn>1</mn></mrow></math> and a temperature-dependent diffusion coefficient <math altimg='si1.svg'><mrow><msubsup><mi>D</mi><mi>s</mi><mtext>lQCD</mtext></msubsup><mrow><mo>(</mo><mi>T</mi><mo>)</mo></mrow></mrow></math> from the recent unquenched lattice QCD data, we analyse the evolution of effective temperature, momentum moments and distribution functions for different initial conditions, including FONLL and EPOS4HQ spectra. We find that charm quarks exhibit dynamical attractors; however, the temperature dependence of <math altimg='si1.svg'><mrow><msubsup><mi>D</mi><mi>s</mi><mtext>lQCD</mtext></msubsup><mrow><mo>(</mo><mi>T</mi><mo>)</mo></mrow></mrow></math> leads to significantly longer relaxation times compared to the strong coupling limit. While the memory loss of initial conditions occurs within <math altimg='si16.svg'><mrow><mo>&#8764;</mo><mn>2</mn><mo linebreak='goodbreak'>&#8722;</mo><mn>3</mn><mrow><mspace width='0.16em' /></mrow><mi>f</mi><mi>m</mi></mrow></math> for <math altimg='si2.svg'><mrow><mn>2</mn><mi>&#960;</mi><mi>T</mi><msub><mi>D</mi><mi>s</mi></msub><mo linebreak='goodbreak'>=</mo><mn>1</mn></mrow></math>, they are delayed to &#8239;&#8764;&#8239;8&#8201;fm for <math altimg='si1.svg'><mrow><msubsup><mi>D</mi><mi>s</mi><mtext>lQCD</mtext></msubsup><mrow><mo>(</mo><mi>T</mi><mo>)</mo></mrow></mrow></math>, becoming comparable to the lifetime of the Quark-Gluon Plasma phase in ultra-relativistic collisions. This indicates that charm quarks may not fully thermalise, especially in small systems such as peripheral or light-ion collisions. We further show that, for <math altimg='si1.svg'><mrow><msubsup><mi>D</mi><mi>s</mi><mtext>lQCD</mtext></msubsup><mrow><mo>(</mo><mi>T</mi><mo>)</mo></mrow></mrow></math>, the deviation from equilibrium becomes as large as <math altimg='si17.svg'><mrow><mi>&#948;</mi><msub><mi>f</mi><mrow><mi>H</mi><mi>Q</mi></mrow></msub><mo linebreak='goodbreak'>/</mo><msub><mi>f</mi><mrow><mi>e</mi><mi>q</mi></mrow></msub><mspace width='0.33em' /><mo>&#8764;</mo><msubsup><mi>p</mi><mi>T</mi><mi>&#946;</mi></msubsup><mo>&#8764;</mo><mi mathvariant='script'>O</mi><mrow><mo>(</mo><mn>1</mn><mo>)</mo></mrow></mrow></math> already at <italic>p<inf>T</inf></italic>&#8239;&#8818;&#8239;2.5&#8201;GeV, rising with <italic>&#946;</italic>&#8239;&#8819;&#8239;4, thus questioning the applicability of viscous hydrodynamics to charm dynamics.

Shile Chen

Vincenzo Nugara

Maria Lucia Sambataro

Salvatore Plumari

Vincenzo Greco

Non-equilibrium dynamical attractors and thermalisation of charm quarks in nuclear collisions at the LHC energy

We present the first complete non-redundant operator basis for the Standard Model Effective Field Theory (SMEFT) at finite temperature, using the imaginary-time formalism. By employing the Hilbert series method on the space-time manifold $\textit{ℝ}$ × $\textit{S}$ , we classify all effective operators up to dimension-six. In constructing the basis, we consistently impose integration-by-parts and equations-of-motion constraints along spatial directions. We further analyze the impact of additional constraints, including the vanishing of the curl of the electric and magnetic fields and gauge choices for the temporal components on an operator basis. We also realize them in terms of static three-dimensional spatial and zero-temperature SMEFT operators. At dimension five and six, we identify intrinsically thermal operators that vanish with temperature. Our framework is fully general and extends to arbitrary mass dimension and compact connected internal symmetry groups.

Joydeep Chakrabortty

Brazil

Switzerland

Bruno Eduardo

Siddhartha Karmakar

Philipp Schicho

Finite-temperature operator basis on $\textit{ℝ}$ 3 × $\textit{S}$ 1 for SMEFT

We compute the thermal photon production rate from a chirally asymmetric quark gluon plasma. We estimate the hard part from scattering of chiral quarks and demonstrate the cutoff independence of the total thermal photon emission rate. This is achieved by combining the hard with the soft contribution evaluated in our previous work [N. Chaudhuri et al., <a href="http://dx.doi.org/10.1103/s8mp-h25n">Phys. Rev. D 112, 094046 (2025)</a>] using the Braaten-Pisarski method of hard thermal loop perturbation theory. It is observed that the presence of chiral imbalance leads to an overall enhancement in the emission rate of thermal photons.

Sourav Duari

Nilanjan Chaudhuri

Pradip Roy

Sourav Sarkar

High energy thermal photons from chirally imbalanced QGP

A new Monte Carlo generator of hadronic collisions is applied for studying model uncertainties regarding calculations of the development of extensive air showers (EAS) initiated by interactions of high energy cosmic rays in the atmosphere. More specifically, we investigate possibilities to modify the model predictions for two EAS characteristics mostly used in experimental studies of cosmic ray composition: air shower maximum depth and the muon number at ground level. For all the considered modifications of the model, we discuss in some detail the underlying physics mechanisms and investigate the impact of the changes, regarding a comparison of the model results to relevant accelerator data.

Sergey Ostapchenko

Tanguy Pierog

Günter Sigl

Addressing uncertainties of model predictions for extensive air showers initiated by high energy cosmic rays