Papers

Blow-up in the self-dual Chern–Simons–Higgs equation has a rich multiscale structure, but the detailed theory has largely focused on the simple regime, where one entire profile resolves each concentration point. By contrast, non-simple blow-up is analytically more delicate: several interacting regular cores must be resolved simultaneously as they collapse toward a single vortex while remaining separated on their own scales. Because of this difficulty, the existence of such solutions has remained a long-standing open problem. To the best of our knowledge, we prove the first existence result for non-simple blow-up solutions of this equation, covering in particular the previously unresolved finite-height Chern–Simons regime. We also show that non-simple clusters have equal limiting core masses, a common profile type, and regular-polygon arrangements. We determine their possible total masses and derive a mass-gap criterion that rules out such blow-up for certain vortex configurations. Our quantitative profile and moment estimates for general finite-height clusters guide the design of the approximate solution and clarify the core interactions underlying the finite-height construction. A separate construction on the unit disk produces two mean-field cores along a sequence with varying Dirichlet traces.

We study spontaneous scalarization near and at extremality in Einstein-Maxwell-scalar theory. As Reissner-Nordström (RN) extremality is approached from below, the nonextremal scalarization existence curves collapse toward a common critical threshold $\alpha_c=1/4$ given by the Breitenlohner-Freedman bound for the near-horizon throat (AdS$_2\times S^2$) of its extremal black hole. For a polynomial coupling, we construct extremal black holes with nonconstant scalar hair, satisfying $M^2+Q_s^2=Q^2$, which places them in the overcharged region $Q/M>1$ beyond the RN bound. A common near-region phase mechanism predicts accumulation toward the RN extremality from both sides, yielding Miransky-type scaling. In the extremal sector, the logarithmic phase interval doubles, halving the exponent which denotes the geometric spacing of successive node scales.

The current debate on higher-order interactions raises a fundamental question: when can systems organized through group interactions be faithfully represented within a graph-based formalism? Recent results show that graph descriptions can reproduce higher-order dynamics exactly or preserve selected macroscopic observables. Yet reducibility does not necessarily imply simplification, as information removed from the interaction structure may reappear as complexity in the effective dynamics, while structural features such as nestedness, heterogeneity, and cross-order correlations may be obscured by the reduction. We argue that formal representability alone is insufficient as a criterion for model choice. Both "simpler" and "equivalent" are question-dependent notions: parsimony must be assessed for the complete structure-dynamics model, and adequacy must be defined relative to the observables, scales, and regimes required by the scientific question. A reduced model may therefore be fully adequate for locating a phase transition or identifying a universality class while being inadequate for reproducing microscopic trajectories, transient dynamics, or structure-function relations. When group structure carries relevant microscopic information, higher-order representations may remain the most direct, interpretable, and parsimonious description, as well as the natural framework for understanding how microscopic organization gives rise to macroscopic behavior and functionality.

We present a generalized exact analytical expression for the upper bound on the CP-violating decay asymmetry in the case of standard vanilla leptogenesis within the minimal type-I seesaw with two Right Handed Neutrinos (RHNs) case scenario as a function of the effective neutrino mass in the hierarchical limit. We derive the bound using a novel analytical treatment of the roots of a quartic equation arising from the conditions for successful leptogenesis, in which the CP asymmetry, effective neutrino mass, and other physical quantities enter as parameters. We find that the upper bound on CP asymmetry is a monotonically increasing function of the effective neutrino mass, asymptotically saturating to a global maximum at the large effective mass regime. We find that our exact analytical expression of the upper bound as a function of the effective neutrino mass is smaller than the previous analytical results in the literature. We also find that the global maximum on CP asymmetry with two RHNs obtained at the large effective mass regime is less than the Davidson-Ibarra bound corresponding to the standard vanilla leptogenesis scenario with three RHNs, leading to a more stringent bound on the lightest RHN mass for the scenario with two RHNs, as expected from some previous results in literature. We find that the deviation from the standard Davidson-Ibarra bound becomes most dramatic for inverted neutrino mass hierarchy, by nearly two orders of magnitude.

Many-body localization is remarkable in that localization persists despite the presence of dynamical interactions. Here we demonstrate the converse phenomenon: enhanced many-body delocalization induced solely by exchange statistics. We study a Aubry-André quasiperiodic system of anyons in one dimension in the absence of density-density interactions. In terms of anyon operators, the system is described by a quadratic Hamiltonian. By analyzing the finite-size scaling of its spectral properties and the inverse participation ratio of many-body eigenstates, we find that increasing the anyonic statistical phase systematically shifts the many-body localization crossover toward larger quasiperdiodic potentials. We further confirm these findings using a dynamical probe, namely the persistence of an initial density imbalance following quenches. Our results establish exchange statistics as an independent mechanism capable of altering many-body localization, revealing a fundamentally distinct route to delocalization in one-dimensional quantum systems.

The rapid emergence of massive black holes in the early Universe, possibly related to Little Red Dots, challenges conventional growth from light seeds. Dark-matter accretion offers a distinct route, and self-interacting dark matter (SIDM) makes it possible by behaving as a collisional fluid. We show that gas inflow can drive strong local contraction of an SIDM halo, assembling a dense reservoir around a pre-existing black-hole seed. The seed then enters a rapid dark-growth phase and can gain several orders of magnitude in mass within less than $1$ Myr before transitioning to slower accretion. We self-consistently follow this process by solving the spherical Euler equations with SIDM self-gravity, collisional heat transport, and an absorbing black-hole sink, rather than imposing an accretion history. The growth depends most strongly on halo mass, with weaker sensitivity to inflowing gas fraction, nuclear size, and seed mass. Gas-inflow-driven SIDM accretion therefore provides an efficient pathway for producing massive black holes in the early Universe.

The discovery of Little Red Dots (LRDs) with JWST has revealed a population of compact, red galaxies hosting rapidly growing black holes at early cosmic times. Their compact morphologies, broad emission lines, weak X-ray emission, and distinctive V-shaped spectral energy distributions indicate a short-lived phase of black-hole growth within a dense nuclear environment. Here we propose that LRDs arise from a transient episode of self-interacting dark matter (SIDM)-assisted black-hole growth during galaxy assembly. In this scenario, gas inflows first establish a compact nuclear thick disk, which modifies the central SIDM distribution and provides the obscuring structure around the accreting black hole. Once the SIDM density near the seed black hole becomes sufficiently enhanced, rapid SIDM accretion drives a major increase in black-hole mass, initiating the transient LRD phase. The resulting obscured growth phase naturally suppresses direct short-wavelength emission and redistributes the radiation field, producing the red continuum and V-shaped spectral signatures of LRDs. This framework links gas inflow, SIDM dynamics, and early black-hole assembly, predicting that LRDs preferentially occur in galaxies undergoing strong nuclear inflow and evolve into ordinary AGN after this transient phase. Unlike models that require globally rare halo histories, long super-Eddington gas growth, or purely phenomenological obscuration, our model ties the overmassive black hole, X-ray weakness, spectral shape, and finite duty cycle to one local gas-triggered SIDM event.

Entanglement scaling provides a powerful probe of universal properties at quantum critical points. In two dimensions, contributions originating from a corner-shaped bipartition exhibit a universal scaling, which is determined by the underlying conformal field theory. We develop a method to extract this corner entanglement entropy from projected entangled pair states directly in the thermodynamic limit. When applied to models at a quantum critical point, we show that the corner contribution exhibits scaling with the effective correlation length, in agreement with the hypothesis of finite-entanglement scaling. Our results for the corner coefficients are consistent with other methods, demonstrating the efficiency of our method for diagnosing strongly-correlated quantum critical points in two dimensions.

Monolayer tin selenide (SnSe) exhibits phase-dependent anharmonic lattice dynamics, yet their consequences for the thermoelectric power factor (PF) and point-defect tolerance remain unresolved. We combine density functional theory, the stochastic self-consistent harmonic approximation (SSCHA), and Boltzmann transport calculations including electron-phonon and electron-defect scattering to investigate monolayer $\alpha$-SnSe (Pnma) and $\beta$-SnSe (Cmcm). In dynamically stable $\alpha$-SnSe, SSCHA renormalizes the finite-temperature phonons without changing the qualitative n-type transport picture. In $\beta$-SnSe, SSCHA removes the harmonic soft-mode instability of the Cmcm phase at 800-1000 K, and thereby enables high-temperature transport calculations; LO/TO-2 is the principal electron-scattering channel. In the lower-density window near $10^{12}$ cm$^{-2}$, the n-type PF reaches 15-19 $\mu\mathrm{W}/(\mathrm{K}^{2}\cdot\mathrm{cm})$ at 800-900 K and exceeds the p-type PF primarily because of the higher electrical conductivity. Se vacancies ($V_{\mathrm{Se}}$) produce weaker electron-defect scattering than Sn vacancies ($V_{\mathrm{Sn}}$), and p-type transport is less defect tolerant than n-type transport in both phases. We define an operational critical defect concentration, $C_{\mathrm{crit}}$, at which the PF decreases by 15% relative to the corresponding defect-free value. The lowest $C_{\mathrm{crit}}$ is $8.841\times10^{-5}$ (approximately 88 ppm) for p-type $\alpha$-SnSe with $V_{\mathrm{Sn}}$; for n-type $\beta$-SnSe with $V_{\mathrm{Se}}$, the 15% threshold is not reached up to $5\times10^{-3}$ (5000 ppm). These results distinguish finite-temperature phonon renormalization in stable $\alpha$-SnSe from anharmonic stabilization in $\beta$-SnSe and provide defect-concentration limits for preserving the PF.

Ten years on, flaring continues in masers associated with NGC 6334I-MM1. Methanol and hydroxyl masers are nearing quiescent values, but water features remain elevated. Several more 1.665 GHz hydroxyl masers, notably, that flared during the accretion event in NGC 6334I-MM1, are identified and presented. Some hydroxyl masers appear to have been active prior to the 2015 event. Possible explanations are discussed. The radial infrared expansion speed during the accretion event is estimated to be ~1.8 AU/d. However, the expansion speed along the North-South outflow is about ten times faster (~18 AU/d). The maser flaring activity illuminated clumpy structure in NGC 6334I-MM1. Quasi-periodicity is reported after the 2015 accretion event in the total integrated 12.2 GHz methanol emission, predominantly in $v_{12.2}=[-12.0,-9.9]$ \kms, after the accretion event in NGC 6334I-MM1. It is not certain if the periodic masers are located in NGC 6334I-MM1, -MM2, or -MM3. The magnetic field, measured from the Zeeman splitting of two ground state hydroxyl lines, undergoes changes before and after the flare.

In this article, we study the dipolar Bosonic quantum fluid. The fluid experiences mean-field, beyond mean-field, and three body interactions. We investigate their competition with dipolar interaction and fragmentation as a result of this competition. We further investigate the elementary excitations and note two distinct dispersion regimes, namely roton-mode and modulational instability. We support our observation by calculating the superfluid fraction and the condensate fraction.

A covariance matrix is often used as a compact surrogate for the statistical model of a measurement. We show that this replacement can change not only a fitted value or its uncertainty, but also the likelihood-ratio ordering of the experiment itself. In a tractable correlated-measurement model, the data separate into an informative component and an ancillary residual disagreement. Exact likelihood inference therefore does not use that disagreement, whereas data-dependent covariance matrices and Gaussian reconstructions after nonlinear transformations can reintroduce it into parameter inference. We quantify the resulting change by the probability mass of the symmetric difference of equally calibrated acceptance regions - the fraction of repeated experiments for which the confidence decision about a tested parameter value changes. In the small-uncertainty regime the ordering discrepancy is generically first order in the total relative uncertainty, whereas conventional and ancillary-conditioned coverage defects begin at second order. At 'coverage-blind' points the leading coverage difference vanishes while the ordering discrepancy remains nonzero. In a representative blind case with 10% total relative uncertainty, about 7.6% of experiments change their confidence decision despite exact calibration of both procedures. The same mechanism connects Peelle's Pertinent Puzzle to the classical literature on ancillarity and relevant subsets: a covariance approximation can manufacture inferential relevance for a goodness-of-fit statistic that is ancillary in the true model. We show directly how this changes the confidence interval reported for the same informative content, and extend the analysis beyond equal statistical uncertainties and beyond the two-measurement case.

The halo nucleon-core system is, by definition, a shallow state nucleus. The nucleon, in most cases a neutron, is loosely bound to the other nucleons forming the core. Accordingly, the system is located inside the universal window; the halo nucleon most likely resides far from the rest of the nucleons, showing a remarkable insensitivity to details of the interaction with the core. The system can be described using a simple nucleon-core interaction, and this description can be extended to the nucleon-nucleon-core system. Specifically, treating the neutron-core and the neutron-neutron-core systems with a Gaussian interaction as a reference, we show trajectories inside the universal window governed by interaction parameters determined from low-energy observables, such as the neutron-core binding energy, scattering length, and effective range. In this way, we can relate properties of different halo nuclei that might seem uncorrelated. In particular, we determine the three-body parameter, the binding momentum at the unitary limit, and show that the two-neutron halo nuclei emerge from that limit following a linear trajectory depending on the neutron-core range.

We develop an encounter-based formulation of restricted diffusion in a bounded domain with multiple targets, resolving separately the boundary local time accumulated on each target. Unlike the single-target problem, the target projection operators do not generally commute with the governing Dirichlet-to-Neumann (DtN) operator, so that its eigenbasis does not diagonalize the local-time dependence. We overcome this difficulty by decomposing the DtN operator into target-restricted blocks. Multi-dimensional Laplace inversion then yields a convergent switching expansion, whose successive terms describe alternating diffusive transfers between the targets. We also derive an equivalent operator-valued renewal equation. For two targets, diagonalizing the target-restricted blocks provides an explicit spectral representation in terms of two DtN block spectra and an inter-target coupling matrix. When the coupling preserves spectral modes, the switching series can be resummed exactly in terms of modified Bessel functions. In general, as the off-diagonal DtN block is smoothing for separated targets, one can resort to low-rank finite-dimensional approximations. We examine an effective two-mode reduction for small, well-separated targets and identify a regime in which repeated inter-target transfers are progressively suppressed. Probabilistic interpretations and implications for diffusion-controlled reactions are discussed.

Active galactic nuclei (AGN) feedback can alter the abundance and spatial distribution of galaxies within large-scale structure. We apply topological data analysis (TDA) to Simba hydrodynamical simulations with varying AGN feedback at $z=0$ to determine which galaxy populations, environments, and spatial scales are most affected. The galaxy two-point correlation function is most sensitive to feedback at $r<1 h^{-1} Mpc$. We then use Betti curves, persistence diagrams, and the 2-Wasserstein distance to quantify feedback-dependent changes in topology. Persistence diagrams show clearer differences than Betti curves, particularly for satellite galaxies. For satellites, loop-like features show significant differences at $\alpha=0.1$–$0.4 h^{-1} Mpc$ for all feedback channels, together with a weaker cumulative difference at $\alpha=1$–$3 h^{-1} Mpc$. The differences are strongest for satellites in quenched halos with $M_h\gtrsim10^{12} M_\odot$. Optimal matching shows that they are driven mainly by shifts in the birth and death scales of loop-like features rather than by their appearance or disappearance. These results indicate that persistent homology can provide complementary constraints on AGN feedback and environmental quenching in galaxy surveys.

This white paper presents the current status of the ecosystem of statistical tools used in High Energy Physics (HEP), and attempts to summarize the views on the future R&D directions. These views have been collected during the latest IRIS-HEP statistical ecosystem blueprint, which took place in February 2026.

Cardiac T1 and T2 quantitative magnetic resonance imaging (MRI) is a technique that provides characterization of a multitude of myocardial pathologies. However, each parameter requires its own specialized acquisition sequence, which may be time-consuming. In this work, we demonstrate that MOLLI, an acquisition sequence commonly used to perform T1 mapping, is also sensitive to T2, and can also be used for myocardial T2 mapping. Although MOLLI is not designed for T2 mapping, its signal evolution inherently depends on both T1 and T2 relaxation. Here, we demonstrate that this dependence is sufficiently strong to allow T2 estimation directly from MOLLI T1-weighted images, using appropriate signal modelling. This finding opens the possibility of obtaining simultaneously T1 and T2 maps from a single MOLLI acquisition, reducing total scan time and potentially improving patient comfort and clinical throughput.

Recurrent structure in supernova (SN) light curves may reveal physical clocks associated with central-engine dynamics, binary orbital motion, or interaction with structured circumstellar material (CSM). We present a multiband photometric reanalysis of the nearby hydrogen-poor superluminous SN (SLSN-I) 2018bsz (z=0.0267), using Swift/UVOT and GROND observations spanning approximately 110 rest-frame days after maximum light. After independently modelling and subtracting the smooth decline in each band, Generalized Lomb-Scargle periodograms reveal recurrent residual variations at broadly consistent phases across ten bands from u to Ks. The strongest individual-band detections, in the g, r, i, z, and J bands, yield periods of 31.5-31.8 days, while the joint multiband analysis gives a rest-frame period of P=31.61 (+/-0.03) days. The modulation is traced over approximately three cycles and is therefore described as quasi-periodic. The signal is robust to the adopted detrending procedure, while comparison-star and lunar-cycle tests disfavour an observational systematic. The modulation is broadly phase-coherent from the optical to the near-infrared, but its amplitude increases towards shorter wavelengths; lower-significance bands also show possible wavelength-dependent shifts in the best-fitting period. The present observations do not uniquely determine the physical origin. Lense-Thirring precession, interaction with CSM structured before the explosion, and post-SN interaction with a surviving companion remain possible. SN 2018bsz provides one of the clearest examples of coherent, month-scale photometric modulation in an SLSN-I.

Graph Neural Networks (GNNs) achieve state-of-the-art performance on graph-structured data, but training and inference on large graphs are often bottlenecked by memory constraints and sparse linear-algebra workloads. Quantum computing offers an alternative set of primitives that may improve scalability for graph learning. Building on the quantum graph neural network (QGNN) framework of Liao et al., this work implements two representative architectures — the Simplified Graph Convolution (SGC) and Linear Graph Convolution (LGC) models — and evaluates them on open benchmark graph datasets and semi-supervised learning tasks using quantum simulation. We compare predictive performance and optimization behavior against classical baselines, showing that the quantum models achieve competitive performance with fewer parameters. Finally, we present a cost gradient analysis that identifies the tasks for which the models showcased are trainable. This is followed by a classical simulability study to find regimes in which the proposed circuits remain robust during training.

Artificial intelligence (AI) and neural networks have driven groundbreaking innovations across numerous disciplines. Optical computing offers the promise of unprecedented speed and energy efficiency in the post-Moore era; however, achieving efficient, practical nonlinear activation using all-optical approaches remains a challenge. Here, we present an optical nonlinear neural processing unit (ONNPU) that implements all-optical nonlinear activation through a self-rectification mechanism. The ONNPU architecture perfectly imitates the structure of digital neural networks, enabling seamless integration with the established deep learning ecosystem. We benchmark ONNPU across nine diverse tasks spanning decision, regression and generation, including accuracies of 98.07% on MNIST and 93.54% on Fashion-MNIST. When integrated into a 201-million-parameter Vision Transformer, ONNPU achieves 82.4% top-1 accuracy on full ImageNet classification (1,000 categories); when integrated into a 117-million-parameter decoder-only Transformer, ONNPU enables short-form story generation that outperforms GPT-2. By addressing more complex and diverse deep learning tasks, ONNPU paves the way toward practical optical machine intelligence, unleashing significant potential for high-performance optical computing.

Spectra of 4.7 and 6.0 GHz excited OH masers from 21 pointings towards known star-forming regions are reported. The C-band observations, using the Green Bank Telescope in full Stokes mode, have measured how polarization properties vary across the maser profiles in each spectrum and vary between different epochs of observation. Seven sources had no detections of masers at any of the OH transitions. Nine sources were observed to have 4.766 GHz masers, which include two new detections in G188.946+0.886 and G196.454-1.677. No new linear or circular polarization was found in any of these masers. Seven and two sources had 6.035 and 6.031 GHz masers, respectively. All 6.035 GHz masers had some level of circular polarization, and three also had linear polarization. Both linear and circular polarization were found in the 6.031 GHz masers in G133.947+1.064, and weak, 100% LCP in G141.918+1.902. Magnetic fields have been calculated from measured Zeeman splittings. The strength and orientation of the fields agree with most previous measurements, although there are some indications that the magnetic fields could be changing. Thermal emission or absorption is seen in several of the 4.7 and 6.0 GHz transitions, many of which have not been reported before.

Conventional astronomical spectrographs are seeing-limited and commonly use multimode fibers to inject starlight into downstream optics. Forthcoming Doppler radial-velocity (RV) instruments are expected to make increasing use of adaptive optics and smaller single-mode fibers (SMF), enabling higher spectral resolution and improved stabilization of the spectrograph point-spread function. However, coupling starlight into SMFs with characteristic diameters of only 5-10 microns at near-infrared wavelengths is technically demanding, requiring alignment procedures that are both efficient and stable throughout the duration of an observation. In this paper, we describe a semi-automated SMF coupling control program being developed for diffraction-limited RV spectrographs. Representative simulations demonstrate that the controller reduces the star-fiber separation from approximately 3.9 mode field diameters (MFD) to 0.11 MFD while increasing a normalized coupling metric from zero to values near 0.6-0.8 after acquisition. Application to closely-separated binary stars is also studied.

Gravitational-wave observations of binary neutron star mergers probe the neutron star equation of state through finite-size effects on the waveform. These include the tidal deformation of the stars due to their respective companion, but for spinning neutron stars also include the spin-induced quadrupole moment of the stars. Typically, to avoid introducing additional equation of state dependent parameters, waveform models relate this quadrupole moment to the tidal deformability through so-called quasi-universal relations. These are derived under the slow-rotation approximation, which at larger spins, i.e., for millisecond pulsars, becomes unreliable. We attempt to extend the existing quasi-universal relations by explicitly accounting for the spin, calibrating it against numerically computed quadrupole moments across a broad set of equations of state and spins $0.15 \leq |\chi| \leq 0.6$ with the $\chi\rightarrow 0$ limit enforced by construction. The resulting spin-extended relation reduces the median absolute percentage error relative to the slow-rotation relation by 66% across this range. Parameter estimation using the spin-extended relation reduces biases in recovered intrinsic parameters in some cases, though biases from mass-spin degeneracies dominate largely when a population is considered. These results provide a more accurate description of the spin-induced quadrupole moment for spinning neutron star binaries, relevant for waveform modelling with third-generation gravitational-wave detectors.

We introduce a trigonometric version of the Nosé-Hoover oscillator in which the quadratic mechanical terms and unbounded thermostat coupling are replaced by bounded trigonometric functions. This formulation replaces the harmonic potential by a pendulum-type potential and confines the thermostat interaction to a bounded periodic form. The resulting two-parameter system is naturally defined on the three-dimensional torus and reduces near the origin, to leading order, to the classical polynomial Nosé-Hoover model. We investigate its global dynamics using Poincaré sections, bifurcation diagrams, Lyapunov spectra, Kaplan-Yorke dimensions, and the Lyapunov Integrability Test (LIT). The numerical results reveal the coexistence of regular and chaotic dynamics and characterize changes in dissipative behavior across the parameter plane. We then analyze the two limiting cases associated with the parameter axes. For $a=0$, we construct two functionally independent first integrals on regular domains, whereas for $b=0$ the dynamics reduces to a family of two-dimensional systems on invariant tori, which are analyzed using Darboux polynomials and exponential factors. First-order averaging near the intersection of these integrable limits yields periodic solutions bifurcating from unperturbed periodic orbits and an obstruction to regular $C^1$ first integrals in their neighborhoods. Independently, differential Galois theory applied to the normal variational equation, together with the Ayoul-Zung and Li-Shi criteria, excludes meromorphic $B$-integrability and non-constant meromorphic first integrals near a particular non-equilibrium phase curve for $ab\neq0$. Thus, despite retaining the local structure of the classical Nosé-Hoover oscillator, its trigonometric counterpart exhibits markedly different global dynamics and integrability.

We present a matrix-free residual-minimization method for preparing guiding-center distribution functions on finite grids. The method minimizes a fixed conservative discrete residual in the physical Jacobian metric using Polak-Ribiere+ iterations with exact quadratic line searches. JAX/XLA evaluates the operator and its adjoint without assembling a four-dimensional matrix; independent magnetic-moment slices are batched and iterations are compiled into one execution graph. An axisymmetric hierarchy verifies invariant references and tests the workflow using a NUBEAM fast-ion distribution together with an EPCoM constants-of-motion representation constructed from it, before matched precise quasi-axisymmetric (precise-QA), HSX, and W7-X calculations. The three-dimensional endpoints reduce the discrete residual and the finite-time variation of the distribution sampled along independently integrated characteristics. Non-negative projection is treated as an optional constrained extension: it leaves the residual operator unchanged but changes the feasible zero-residual set and endpoint selection. Results are finite-grid, finite-time evidence and do not establish a continuous equilibrium, grid convergence, strict positivity, or a transport prediction.

The processes of paired charmonium and bottomonium production in Z-boson decays are investigated within the relativistic quark model. Various decay mechanisms are examined, and relativistic decay amplitudes are constructed, taking into account the relative momenta of heavy quarks. Decay widths are calculated for various mechanisms in the nonrelativistic approximation and taking into account relativistic corrections.

We revisit the $e^+e^- \to \phi \pi^+\pi^-$ reaction within the $K_1$-$\bar{K}$-$K$ triangle dynamics framework, in which the $e^+e^-$ pair annihilates through one-photon exchange approximation to produce a $K_1\bar{K}$ pair, followed by the $K_1 \to\phi K$ decay and the final-state $K\bar{K} \to \pi^+\pi^-$ rescattering. With the same theoretical formalism and model parameters, the $e^+e^- \to \phi K^+K^-$ reaction is investigated, and it is found that the predicted total cross sections for the $e^+ e^- \to \phi K^+ K^-$ reaction are in good agreement with the existing BESIII measurements. Our study shows that the triangle singularity in the $\phi K^+K^-$ channel is strongly suppressed, because the higher $K^+K^-$ mass threshold shifts the kinematics away from the triangle singularity condition and the phase space near the $K_1\bar{K}$ threshold is very limited. Moreover, the interference between the tree-level and loop amplitudes eliminates the remaining signal. These combined effects naturally explain the absence of a distinct $\phi(2170)$ signal in the $e^+ e^- \to \phi K^+ K^-$ reaction, provide a strong test of the model, and reinforce the picture that both reactions are governed by the same underlying mechanism, in which the $\phi(2170)$ state is produced in the $e^+ e^-$ annihilation from the $K_1$-$\bar{K}$-$K$ triangle loop.

Massive stars, including Wolf-Rayet stars, are predominantly found in binary systems. These systems are known to emit both thermal emission from stellar winds and, occasionally, non-thermal emission produced by relativistic electrons accelerated in the wind-wind interaction region. We intend to provide the most complete census of radio emission from WR stars in the Galactic plane, using the SARAO MeerKAT Galactic Plane Survey (SMGPS) complemented by the MeerKAT Galactic Center Survey. Our main motivation is to identify hints of synchrotron radio emission indicative of particle-accelerating colliding-wind binaries (PACWBs). We compiled an input catalogue of 428 WR stars positionally covered by the SMGPS and the MGCS. Using the survey data, we measured the radio emission at 1.3 GHz for detected WR stars. We also measured the upper limits for objects located in sufficiently low radio background regions. For detected objects, we searched for a radio excess by comparing the measured fluxes to two different evaluators of the thermal emission from massive star winds. We detected 23 targets and determined the upper limits for 279 WR stars. Among the detected objects, 15 display a (significant or potential) radio excess that cannot be explained by unresolved circumstellar emission of any kind. After removing already known PACWBs, we report the identification of 12 potential new PACWB candidates. Our study has led to the compilation of the most extensive catalogue of Galactic WR radio emission to date, based on a homogeneous dataset covering the Galactic plane. The low detection rate indicates either a low occurrence rate of synchrotron emission or substantial attenuation by turnover processes that are clearly dominated by free-free absorption from the WR wind material. Our results open the door to dedicated follow-up observations aimed at ascertaining the nature of the identified radio excesses.

The total decay width of the Higgs boson, $\Gamma_H$, encodes all of its decay modes; any decay into particles beyond the Standard Model (SM) would increase $\Gamma_H$ above the SM prediction of 4.1 MeV. In this Letter, a direct, on-shell measurement of $\Gamma_H$ is reported, exploiting the interference between the resonant $H \to \gamma\gamma$ amplitude and the continuum diphoton background, which distorts the diphoton invariant mass distribution in a way that depends on $\Gamma_H$ without requiring assumptions on the Higgs boson couplings. Using 140 fb$^{-1}$ of proton-proton collision data at $\sqrt{s}=13$ TeV recorded by the ATLAS detector during Run 2 of the LHC, an observed (expected) upper limit of $\Gamma_H < 307$ (258) MeV is set at 95% confidence level, approximately 75 (63) times the SM prediction. Unlike indirect off-shell constraints on $\Gamma_H$, this measurement does not rely on assumptions about the Higgs boson couplings, providing a novel complementary probe sensitive to potential Higgs boson decays into new particles.

A soliton microcomb requires increasing pump power as its optical bandwidth is broadened. Resonant pumping through an auxiliary microresonator can reduce the power required to sustain a soliton, but simultaneously increases the power required for soliton formation. We show that this competition leads to optimal inter-resonator coupling, and the predicted minimum input pump power scales as the two-thirds power of the comb bandwidth, in contrast to the quadratic scaling under direct pumping. Experiments support the opposing power trends, providing a design rule for power-efficient, ultra-broadband soliton microcombs.