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Monday 5 October

High Energy Physics (Theory)

Checking the Schwinger-Dyson equation in the purely open matrix-tensor model

Daniel L. Jafferis, Liza Rozenberg, Diandian Wang et al. (+1 more)

We test the proposed matrix-tensor description of three-dimensional gravity using a Schwinger-Dyson relation in its purely open sector. We enumerate and classify the topological contributions to a cylinder amplitude. Under a proposed counting prescription motivated by Virasoro TQFT, we find agreement with the conjectured unit difference between the numbers of contributing manifolds associated to the two interaction terms in the potential. By contrast, counting all inequivalent surface embeddings separately would instead give a mismatch. This comparison highlights the importance of specifying the set of bulk topologies to be included in the gravitational path integral.
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All authors Daniel L. Jafferis, Liza Rozenberg, Diandian Wang, Cynthia Yan

Cosmology and Nongalactic Astrophysics

And Then There WEre Baryons (ATWEB): The Baryon Budget of the Universe in Halos and the IGM over 13 Billion Years of Cosmic Time

Mohammadreza Ayromlou, G. Mark Voit, Thomas H. Reiprich et al. (+2 more)

Observations of the local Universe show that, except in the most massive galaxy clusters, the baryon fraction within halos falls below the cosmic mean. This deficit can be characterized using the previously established closure radius, the halocentric distance within which the enclosed baryon fraction reaches the cosmic value. Using the TNG, EAGLE and SIMBA simulations, we examine how, when, and on what scales the baryonic and dark matter distributions diverge. At z=0 less than 30% of cosmic baryons reside within galaxy-hosting halos, compared with ~45% of the dark matter, leaving over 70% of all baryons in the IGM. Building on the closure radius, we introduce three further characteristic scales: the compensation radius, closure envelope, and compensation envelope. The compensation radius marks where the enclosed total mass recovers its gravity-only value, and today it typically lies inside the closure radius in all three models. The closure and compensation envelopes are the largest median radii across halo mass. Galaxy groups provide the largest contribution per dex of halo mass to IGM enrichment with halo-associated baryons and redistribute baryons over the largest distances. They set the closure envelope, which reaches ~2-6.5 Mpc at z=0, depending on the model. The closure radius usually increases with cosmic time at fixed halo mass. Tracking individual halos, we find open baryon cycles with substantial redistribution beyond halo boundaries across all halo masses, while even the progenitors of today's most massive clusters fall below the cosmic baryon fraction. The compensation envelope grows toward low redshift, reaching ~1.5-5.5 Mpc at z=0. Across cosmic time, it coincides with the scale on which the matter power spectrum recovers its gravity-only form, establishing a direct link between the spatial extent of baryon redistribution and the impact of feedback on large-scale structure.
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All authors Mohammadreza Ayromlou, G. Mark Voit, Thomas H. Reiprich, Cristiano Porciani, Dominique Eckert

Quantum Physics

Protecting bosonic codes from ancilla-induced errors with continuous-variable flags

Thomas Décultot, Ronan Gautier and Mazyar Mirrahimi

Bosonic quantum error correction represents a route towards significant hardware overhead reduction for fault-tolerant quantum computation. However, controlling quantum harmonic oscillators that encode the quantum information comes with its own challenges. In many platforms such as superconducting circuits and trapped ions, the bosonic degree of freedom is controlled by an ancillary qubit whose decay during a qubit-oscillator gate propagates to the oscillator as a continuous error. Such errors generally lie beyond the scope of errors that the bosonic code is capable of correcting. We introduce the continuous-variable flag: an auxiliary oscillator coupled to the ancilla whose phase-space position encodes the continuous error corrupting the storage mode. After the gate, a heterodyne measurement of the flag estimates this continuous-variable error and a subsequent feedback control undoes it up to a bosonic code stabilizer. The scheme requires no new ingredients, as the flag is driven by the same dispersive coupling, displacements and rotations that implement the gates it is supposed to protect. We construct sequences protecting conditional rotations to all orders in ancilla decay with one flag, and conditional displacements to first order with one flag and to all orders with two. Simulations with realistic circuit-QED parameters predict more than three orders of magnitude fewer logical errors for the parity measurement of a four-component cat code, and a finite-energy GKP logical lifetime near its noiseless-ancilla bound. By discretizing continuous-variable errors, the flags introduced in this work are a useful tool for any hybrid oscillator-qubit processor, and open the route towards fault-tolerant simulation and computation with bosonic modes.
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Astrophysics of Galaxies

Cracking open the "dragon egg": ALMA 1.3mm observations of a compact, young high-mass core candidate at 30mas resolution

A. T. Barnes, J. D. Henshaw, Á. Sánchez-Monge et al. (+14 more)

Massive prestellar cores are a central assumption of core-accretion models of high-mass star formation, yet convincing observational examples remain rare. The "dragon egg" (C2c1a) core in the infrared-dark cloud G028.37+00.07 has been proposed as a promising compact high-mass core candidate. We present new ALMA Band 6 observations at $0.035''$-$0.078''$ ($\sim175$-400 au at 5 kpc), providing one of the most stringent high-resolution tests of such a candidate. The region resolves into multiple fragments, but the brightest component, C2c1a(a), remains a single compact continuum peak down to $\sim175$ au, with a deconvolved radius of $\sim87$ au and a nearest neighbouring fragment at a projected separation of $\sim2400$ au. The continuum peak reaches a brightness temperature of $\sim40$ K, exceeding the $\sim10$ K gas temperatures inferred from lower-resolution NH$_3$ observations and indicating a strong radial temperature gradient. Continuum-based mass estimates range from $\sim2$ to $\sim30$ $M_\odot$ (implying extreme densities of $n_\mathrm{H2} > 10^9$cm$^{-3}$), depending on temperature, while lower-resolution data indicate a much larger mass reservoir of $\sim110$ $M_\odot$ on $\sim10^4$ au scales. The spectrum shows no strong hot-core tracers and only weak, spatially extended H$_2$CO and CO emission; no high-velocity outflow can be unambiguously associated with C2c1a(a). We conclude that C2c1a(a) is an exceptionally compact core embedded within a massive cold reservoir, with no additional compact fragments detected within the present resolution and sensitivity limits, potentially tracing the earliest formation of a central protostellar "seed" within a still-dominant reservoir. [abridged]
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All authors A. T. Barnes, J. D. Henshaw, Á. Sánchez-Monge, P. Caselli, I. Jiménez-Serra, J. E. Pineda, K. Immer, M. De Simone, R. J. Parker, F. Fontani, E. Redaelli, S. N. Longmore, L. Böhm, Q. Zhang, C. Y. Law, G. Cosentino, J. C. Tan

Instrumentation and Methods for Astrophysics

Optimal Photon Counting with Fast, Low Noise Astronomical Imagers

Jack T. Dinsmore, Christopher Layden, Roger W. Romani et al. (+9 more)

Measuring rapid astrophysical phenomena requires many short exposures, which suffer from repeated read noise. A variety of recent technologies are achieving sub-electron read noise, which enable rapid time-domain studies of faint sources. These data can be analyzed with traditional methods, but the ability to resolve individual electrons enables a new class of more precise, photon-counting techniques. We present a photon-counting method for sub-electron read noise detectors which delivers optimal statistical uncertainties. We focus on Complementary Metal-Oxide-Semiconductor (CMOS) detectors and demonstrate our method on optical data collected by CMOS instrument "proto-Lightspeed," recently commissioned at the Magellan Clay telescope at Las Campanas Observatory. The method can be applied to non-CMOS detectors as well, such as skipper CCDs and linear-mode avalanche photodiodes. The method substantially improves analysis of faint sources, increasing signal to noise ratios by up to $\sim 130\%$, which would require 5.3$\times$ more observing time to accomplish with data alone. As an example we show detections of four normal rotation-powered pulsars with confirmed optical pulses, achieved in under two hours of total exposure. We provide the lightspeedpy pipeline for reducing proto-Lightspeed data with both photon counting and standard techniques.
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All authors Jack T. Dinsmore, Christopher Layden, Roger W. Romani, Vera L. Berger, Kevin B. Burdge, Geoffrey Mo, Deepto Chakrabarty, Emma T. Chickles, Gabor Furesz, Juliana García-Mejía, Dave Osip, Jack Piotrowski

High Energy Physics (Phenomenology)

Minimal cascade decay of the top quark through a new scalar

Bogdan A. Dobrescu, Max H. Fieg and Alessandro Russo

We explore a possible decay of the top quark into a new scalar $\phi_t$ plus a charm quark. The decay is mediated by a dimension-5 operator that may be generated by the exchange of a heavy vectorlike quark, $\chi$, and can have a branching fraction close to a percent. In a minimal model, $\phi_t$ decays due to the same operator that allows the nonstandard top decay, leading to a final state involving a $c$ jet, a $b$ jet and a $W$ boson. Hence, the top quark would undergo a nonstandard cascade decay through $\phi_t$ and then through an off-shell top quark. The main nonstandard collider signal is a $t \bar t \to c \, \bar c \, b \, \bar b \, W^+ W^-$ process. In addition, production of the vectorlike quark at the LHC would lead to a signal of the type $\chi \phi_t \, j \to 3c + b \, \bar b \, W W j$.
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High Energy Physics (Theory)

A New Entropy Puzzle in ABJM

Alexandre Belin, Seyed Morteza Hosseini, Palash Singh et al. (+2 more)

We point out a puzzle about BPS black holes in AdS$_4\times S^7/\mathbb{Z}_k$: the entropy grows when $k$ increases although the number of gauge-invariant operators in the dual conformal field theory that can contribute to the entropy grows as $k$ decreases, due to the presence of monopole operators. Analyzing the superconformal index of ABJM, we show that the same puzzle exists for finite $N$ in the large charge limit. We propose a resolution based on an increasing number of trace relations as $k$ decreases, which dominates over the other effect. We argue that this mostly affects fortuitous operators and we provide an explicit example of a fortuitous operator that disappears at small $k$.
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All authors Alexandre Belin, Seyed Morteza Hosseini, Palash Singh, Rita Vadala, Alberto Zaffaroni

High Energy Physics (Theory)

All-Orders Classical Soft Graviton Theorems in the Newtonian Limit and Beyond

Debanjan Karan, Babli Khatun, Raghu Mahajan et al. (+2 more)

The classical soft graviton theorem aims to determine certain terms in the early- and late-time tails of the gravitational waveform produced in a scattering process, using only the asymptotic momenta of the scattered objects. In this paper we find an infinite series of leading-logarithmic tail terms in the Newtonian limit, where the incoming and outgoing particles move slowly, but the scattering itself can be violent. The all-orders conjecture of Alessio, Di Vecchia and Heissenberg agrees with our results for two-particle scattering, but does not hold in general when the initial or final state contains three or more particles. We also propose an all-orders conjecture for these tails beyond the Newtonian limit, but do not prove it. Nevertheless, the conjecture passes several nontrivial consistency checks.
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All authors Debanjan Karan, Babli Khatun, Raghu Mahajan, Biswajit Sahoo, Ashoke Sen

Earth and Planetary Astrophysics

First Direct Identification of a Multi-Star Microlens System Hosting a Planet

Sean K. Terry, David P. Bennett, Jean-Philippe Beaulieu et al. (+11 more)

Nearly 25 years have passed since gravitational microlensing delivered its first exoplanet discoveries. The relative proper motion between lens and source systems allows them to be resolved as they separate on the sky over many years. This enables scientists to study light coming directly from the lenses and place tight constraints on the physical properties of these planetary systems. In this paper we present an analysis of high angular resolution images of the microlensing target OGLE-2006-BLG-284 using Keck adaptive optics and HST data taken more than 15 years after the event. We clearly detect the lens system and measure its motion across the Keck and HST epochs. We measure a lens-source relative proper motion of $5.80 \pm 0.15$ mas yr$^{-1}$. A combination of the light curve parameters and the host star(s) brightnesses in $V,\, I$, and $K$ passbands gives primary and secondary host star masses of $M_{\rm 1} = 0.43 \pm 0.05\,M_{\odot}$ and $M_{\rm 2} = 0.12 \pm 0.02\,M_{\odot}$, and a planetary companion mass of $m_p = 165^{+40}_{-33}\,M_{\oplus}$. Although we are unable to determine if the planet orbits one or both stars in the system, our analysis motivates next-generation high-precision RV measurements that can distinguish these two possibilities. This is the first direct detection of flux coming from a two-star microlensing system which hosts a planet.
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All authors Sean K. Terry, David P. Bennett, Jean-Philippe Beaulieu, T. Dex Bhadra, Aparna Bhattacharya, Joshua W. Blackman, Ian A. Bond, Andrew A. Cole, Przemek Mróz, Kansuke Nunota, Clément Ranc, Natalia E. Rektsini, Daisuke Suzuki, Aikaterini Vandorou

Physics and Society

The search process of professional detection dog teams in realistic environments

Stephan P. Kaufhold, Jack Terwilliger, Samantha Kefer et al. (+1 more)

Scent detection work is a form of interspecies cooperation. Dogs sample odors that handlers cannot perceive, and handlers decide where the team searches and which of the dogs' responses counts as a find. However, detection performance is predominantly measured by outcomes and dog characteristics. To better observe the search process itself, we collected data at two judged detection events (109 searches of 37 professional narcotics teams). All searches were video-recorded and included an outdoor area, a vehicle, and a building search, each with two targets and food and currency distractors. We synchronized computer-vision tracking of dogs and handlers with continuous behavioral coding. We observed variation across teams and in total 42% of targets were found. Finds were rarely missed because dogs never came close to a target or because handlers did not call an indication. Rather, most were missed at the encounter itself, as dogs came within 1~m of nearly every target but indicated on only about one in six of these passes. Handlers did not behave differently near targets than near distractors before their dogs responded. Finding targets was moderately consistent within teams, whereas false calls depended on the individual search and on specific items. Observing the search process suggests that success is a result of the dog's response, the handler's decision, and their coordination.
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All authors Stephan P. Kaufhold, Jack Terwilliger, Samantha Kefer, Federico Rossano

Quantum Physics

Black Hole Radiation Decoding in the Haar Random Oracle Model

Ezekiel Cochran and Atul Mantri

We prove optimal query bounds for recovering a single qubit from black-hole radiation in the Haar random oracle model, when the remaining black hole contains at most one sixteenth of the system's qubits. Recovery with any constant Haar-averaged advantage over trivial decoding requires queries proportional to the Hilbert-space dimension of the remaining black hole. The lower bound is unconditional for decoders chosen independently of the sampled unitary, allows arbitrary computation between queries, and access to $U, U^\dagger, U^*, U^\mathsf T$ along with the controlled variants. An existing decoder using only forward and inverse queries attains a matching bound. The proof uses a path recording oracle to compare real and maximally mixed states. As applications, we obtain an efficiently preparable, statistically far, computationally indistinguishable (EFI) pair and quantum commitments relative to a public Haar oracle, as well as prove a tight linear rank lower bound for Uhlmann transformation on a fixed-target family.
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Astrophysics of Galaxies

Probing departures from Schwarzschild geometry with the S301 star and kilometre-baseline interferometry

Rodrigo P. Silva, Alexandre C. M. Correia and Paulo J. V. Garcia

The S301 star reaches a pericentre one tenth that of S2, opening a new regime for probing black-hole spin and departures from Schwarzschild. We develop a post-Newtonian secular Hamiltonian framework for bound geodesics in stationary, axisymmetric spacetimes and compute the maximum projected astrometric deviation over one orbit. At the expected GRAVITY+ precision, S301 can probe several nonrotating geometries and sizeable spin-induced deviations, while kilometre-baseline interferometry can probe much smaller departures, establishing S301 as a powerful test of the spacetime geometry of Sgr A*.
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Materials Science

Direct-Write Chemical Vapor Deposition

Eeshan Ketkar, Swarnabha Chattaraj, Koichi Tanaka et al. (+2 more)

Direct-write pattering, using chemical vapor deposition through a nozzle, enables localized film growth using high-purity precursors standard to the electronics industry. Yet, achieving sub 100 $\mu\mathrm{m}$ feature control has been limited by nozzle design and unquantified precursor surface diffusion. Here, we report a direct-write chemical vapor deposition platform that employs a 10 $\mu\mathrm{m}$ tip diameter glass micro-nozzle mounted on a scanning stage above a heated substrate in ultra-high vacuum. Using this approach, we demonstrate the continuous single-pass writing of 500 $\mathrm{nm}$ thick metallic aluminum lines with a 30 $\mu\mathrm{m}$ linewidth on titanium nitride-coated silicon. This capability enables maskless, localized growth under systematically varied deposition conditions on a single substrate. To analyze the resulting deposit profiles, we introduce a transport framework coupling Knudsen gas emission from the micro-nozzle with surface diffusion to extract the effective precursor diffusion length, $L_d$. $L_d$ captures the combined impact of precursor surface mobility, residence time, substrate temperature ($165^{\circ}\mathrm{C}$ to $205^{\circ}\mathrm{C}$), growth duration, and nozzle height, contracting from 17.4 $\mu\mathrm{m}$ down to 3.2 $\mu\mathrm{m}$ at elevated temperatures. These results establish $L_d$ as a quantitative parameter for evaluating laterally confined chemical vapor growth and predicting feature resolution limits. This approach provides a practical methodology to measure and quantify precursor surface transport in localized film synthesis.
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All authors Eeshan Ketkar, Swarnabha Chattaraj, Koichi Tanaka, Samy Kouidri, Supratik Guha

Instrumentation and Methods for Astrophysics

Armillary: A Label-Free Coordinate System for Stellar Spectra

Yuan-Sen Ting and Serat Saad

A stellar spectrum is determined by a few parameters, so a set of spectra lies on a low-dimensional manifold with those parameters as its coordinates. We introduce Armillary, which generalises the Sequencer of Baron and Ménard from an ordering to multidimensional coordinates, constructed from the spectra alone. Two stars are compared by the Wasserstein distance between their signed absorption profiles. Shortest paths through a nearest-neighbour graph measure distance along the manifold and give the coordinates, and the same graph transfers the labels of a few stars to all the others. The coordinates are more nearly linear in $T_{\rm eff}$ and $\log g$ than principal components, t-SNE, UMAP or an autoencoder. The label transfer, without deep learning, is more precise than the first three and comparable to the autoencoder. On 202,932 APOGEE DR17 stars, an illustrative draw of 32 training stars recovers the ASPCAP $T_{\rm eff}$, $\log g$ and [M/H] of held-out dwarfs and giants, with $1\sigma$ errors of 100 K, 0.18 and 0.083 dex. Resolving the two $\alpha$ sequences of the disc in [$\alpha$/M] for giants takes 128 training stars, and with 2048 the four errors improve to 33 K, 0.06, 0.026 and 0.022 dex. On 104,799 DESI stars, 32 training labels from APOGEE recover the stellar parameters to 129 K, 0.25 and 0.203 dex, even for spectra degraded to a signal-to-noise of about 20. At a signal-to-noise of about 100, 2048 training labels resolve the two $\alpha$ sequences of the disc in DESI giants, with errors against APOGEE of 51 K, 0.07, 0.047 and 0.026 dex. The code is public at https://github.com/tingyuansen/armillary.
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High Energy Physics (Phenomenology)

Molecular Structure Effects in Low-Lying $P$-wave Bottom-Strange Meson Spectrum

Wei Hao, Guan-Ying Wang, M. Atif Sultan et al. (+1 more)

Recently, the LHCb Collaboration reported a new narrow bottom-strange meson, $B_{s0}^*(5700)$ with mass $M= (5698.9 \pm 1.5 \pm 0.6)$~MeV, width $\Gamma<9.8$~MeV, and spin-parity $J^P=0^+$ in the $B_s^0\pi^0$ invariant-mass spectrum. Motivated by this observation, we study the low-lying $P$-wave $B_s$ mesons in a two-stage refined constituent quark model. The one-loop radiative corrections to the confinement–one-gluon exchange potential ($\alpha_s^2$) lower the whole multiplet by $25$–$50$~MeV and improve the level ordering; however, the scalar $B_{s0}^*$ mass still exceeds the LHCb data by $\sim120$~MeV in a purely compact picture. The inclusion of the coupled-channel dynamics is decisive: the $BK$ threshold, lying close to the scalar mass, generates a sizeable meson–meson (molecular-like) component that pulls the pole down to $\sim5727$~MeV, within $30$~MeV of the measurement, and simultaneously suppresses the $S$-wave phase space, naturally accounting for the anomalously narrow width. Consistent results are obtained for the $1^+$ $B_{s1}$ partner, for which we predict a mass $\sim5747$–$5755$~MeV, in agreement with the chiral-doubling scenario. The $B_{s1}$ state is expected to be very narrow and decaying mainly through the isospin-violating $B_s^*\pi^0$ and radiative $B_s\gamma$, $B_s^*\gamma$ modes, providing a clear discovery target at LHC Run~3. The $E1$ radiative widths of the $j_\ell=1/2$ states are predicted at the $50\sim 60$~keV, and the strong width of the pure $j_\ell=3/2$ state $B_{s2}^*(5840)$ ($1.5$~MeV) reproduces the measurement. Our results support the interpretation of $B_{s0}^*(5700)$ as a near-threshold scalar with strong molecular dressing and establish the predicted $1^+$ $B_{s1}(5747)$ as the decisive test of the hadronic dynamics in the $B_s$ sector.
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All authors Wei Hao, Guan-Ying Wang, M. Atif Sultan, En Wang

General Relativity and Quantum Cosmology

Noninertial Reference Frames in Special Relativity

Justo Pastor Lambare

Although the special theory of relativity was conceived to relate inertial reference frames, it is not generally known by beginning students, or even by academics not specializing in general relativity, that it can be applied to noninertial reference frames. The general perception among non-specialists seems to be that noninertial reference frames can only be described through general relativity. This situation has led to some controversy regarding the necessity of general relativity to address problems involving accelerated systems, such as the twin paradox and the description of rotating reference frames. We discuss the controversy and propose that, to avoid the present confusion, the local validity of special relativity in the absence of gravitation, despite the use of noninertial frames, should be explicitly and clearly stated at an early stage of the learning process.
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Mathematical Physics

Araki Cohomology of the de Sitter Scalar Discrete Series

Maryam Bajalan, Jean-Pierre Gazeau, Hamed Pejhan et al. (+1 more)

Building on the recently established de Sitter (dS)-covariant indecomposable Krein realization of the scalar discrete-series unitary irreducible representations $\Pi_{p,0}$, $p=1,2,\cdots$, of $\mathrm{SO}_0(1,4)$, naturally organized into a Gupta-Bleuler triplet, we uncover its underlying Araki-cohomological structure. We show that the Krein-Gupta-Bleuler construction provides a concrete realization of Araki's standard Gupta-Bleuler triplet, with its non-split indecomposable structure encoded by non-trivial first cohomology classes related by adjunction. We further show that the reducible intermediate sector naturally resolves into its two irreducible components, inducing a corresponding decomposition of the extension classes and yielding a four-layer refinement of Araki's standard triplet. The resulting Gupta-Bleuler quadruplet provides a finer cohomological resolution, distinguishing the physical representation from its complex-conjugate sector.
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All authors Maryam Bajalan, Jean-Pierre Gazeau, Hamed Pejhan, Petr Siegl

High Energy Physics (Phenomenology)

Primordial black holes and scalar-induced gravitational waves in the supersymmetric 331 model from SU(6)

Imtiaz Khan, Niamat Ullah, Ali Muhammad et al. (+4 more)

We study primordial black holes and scalar-induced gravitational waves in the supersymmetric 331 model based on SU(6). The inflaton continues to be the D-flat radial combination of the 331 symmetry-breaking fields Phi and Phi-bar, fields which are already accountable for the CMB branch. A gauge-invariant contribution that is localised in the Kaehler frame function causes the force in the Einstein frame to decrease over a finite range of the field and results in a temporary nonattractor phase. We calculate the supergravity potential and the radial metric, evolve the background and the Mukhanov-Sasaki modes, and assess the neutral covariant Hessian along the local region. The CMB trajectory is still in agreement with the present observational constraints while the curvature spectrum attains a value of P_zeta ~ 5.38 x 10^-3 when k ~ 1.88 x 10^13 Mpc^-1. The enhanced spectrum leads to a primordial black hole distribution with a mass comparable to that of an asteroid and to a maximum in the scalar-induced gravitational wave signal at a frequency of 3.17 x 10^-2 Hz with Omega_GW,0 h^2 ~ 9.41 x 10^-11. The local geometry also results in a clear hierarchy of sensitivities. The gravitational wave spectrum changes smoothly as one moves along nearby trajectories whereas the Gaussian tail of the primordial black hole distribution changes much more rapidly. The positive eigenvalues of the neutral transverse Hessian remain throughout the reference trajectory. A Gaussian critical collapse calculation yields a reference integrated primordial black hole fraction of near 9.08 x 10^-3, while recent nonlinear studies suggest significant corrections to the statistics of rare collapses at the scalar power achieved here.
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All authors Imtiaz Khan, Niamat Ullah, Ali Muhammad, Mussawir Khan, G. Mustafa, Farruh Atamurotov, Ahmadjon Abdujabbarov

Mathematical Physics

Inverse construction of exact atmospheric models and the 3.7–4.4\,mHz acoustic resonances

O. V. Kaptsov

Large explosive eruptions and earthquakes excite atmospheric oscillations near 3.7 and 4.4\,mHz that couple to the solid Earth. For vertically propagating linear acoustic–gravity waves in a hydrostatic ideal-gas atmosphere, the travel-time formulation gives a Klein–Gordon equation with a potential $Q(\tau)$. We establish three main results. First, for every potential admitting a positive zero-energy solution, the corresponding atmospheric profiles are constructed explicitly by quadrature; this extends the known reflectionless profiles of constant $Q$. Second, Darboux–Crum potentials give a smooth atmosphere that reproduces the U.S. Standard Atmosphere between 11 and 100\,km to within 3\,K and is exactly transparent to vertical waves above its cut-off; it supports no damped overtone near 4.4\,mHz, and its ground-confined mode below the cut-off is perfectly trapped. The observed spectrum therefore requires a cut-off barrier of finite thickness connecting the lower atmosphere to the thermosphere. Third, a Rosen–Morse barrier gives an exactly solvable atmosphere with a closed-form hypergeometric resonance condition. Its resonances at 3.76 and 4.37\,mHz, with leakage quality factors 173 and 20, explain the different damping of the two oscillations: the fundamental lies below the top of the mesospheric cut-off barrier and leaks by tunnelling, whereas the overtone lies above it. Full-wave computations for event-specific atmospheres reproduce the reported 3.7–3.8\,mHz fundamental oscillation in all six events, of seven considered, in which such a mode was identified.
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General Relativity and Quantum Cosmology

Viscous Ghost Dark Energy in $f(Q, L_m)$ Gravity: Observational and Thermodynamic Validity

Ajay Kumar and Pankaj Kumar

We investigate the cosmological implications of viscous ghost dark energy in the framework of modified $f(Q,\mathcal{L}_m)$ gravity by considering the linear functional form $f(Q,\mathcal{L}_m)=\alpha Q+\beta\mathcal{L}_m$. The non-minimal coupling between geometry and matter together with bulk viscous effects modifies the cosmic dynamics, leading to an analytical solution of the background Friedmann equations. Since the expansion history depends only on effective combinations of the model parameters, the observational analysis is performed in terms of the corresponding effective background parameters. We constrain the model using the latest joint compilation of Pantheon+ including SH0ES Type Ia supernovae, Cosmic Chronometers, and DESI baryon acoustic oscillation measurements. The model provides a satisfactory description of the late-time expansion history and reproduces the observed transition from decelerated to accelerated cosmic expansion. A statistical comparison with the standard $\Lambda$CDM model is performed using the minimum $\chi^2$, Akaike Information Criterion (AIC), and Bayesian Information Criterion (BIC). Furthermore, the thermodynamic viability of the model is examined through the evolution of the total entropy, and the generalized second law of thermodynamics is found to remain valid throughout the cosmic evolution.
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Astrophysics of Galaxies

EMIR confirmation of the high-z Ly{\alpha} blob SHARDS20018464

S.Zarattini, F. Garzón and C. Muñoz-Tuñón

A spectroscopic follow-up of the Ly$\alpha$ blob SHARDS20018464 was performed using the infrared spectrograph EMIR (Espectrógrafo Multiobjeto Infra-Rojo) at the 10.4 m GTC telescope, equipped with its newly upgraded H2RG focal plane array detector. We observed the blob in the Ks band, which corresponds, at the photometric redshift of $z=3.49$ presented in the literature, to the rest-frame visible part of the spectrum. Thanks to the sensitivity of EMIR, we were able to identify the [OIII] emission doublet at the position of the blob and the companion galaxy. The flux of the detected lines is of the order of $10^{-17}$ erg s$^{-1}$ cm$^{-2}$, obtained with 4-hour exposure. The mean redshift derived by analysing the two lines individually is $z=3.59\pm0.01$, slightly higher than the photometric one, although in agreement within the uncertainties. We also estimated the flux of the two lines and their ratio, which was found to be $R = 2.92$, very close to the theoretical prediction of 2.98. This is a strong analytical confirmation that the observed emissions correspond to the [OIII] doublet. Within uncertainties, the redshift of the blob confirms the photometric one reported in the literature, as well as the physical properties inferred for it. Its remarkably small size (5-8 kpc vs. $\sim 100$ kpc for typical samples) and its position aside the companion galaxy also confirm the previously-proposed idea that this object could be the first of a new class of compact Ly$\alpha$ emitters. Moreover, the data support the scenario of photo-ionisation due to a cluster of young and massive stars.
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High Energy Physics (Phenomenology)

Lunar radio emission from dark photon dark matter

Ariel Arza

The dielectric surface of the Moon provides an efficient interface for the conversion of dark matter dark photons into radio waves. This work explores a novel detection strategy that aims to capture this radio emission using standard radio telescope antennas. Detailed sensitivity projections are presented that demonstrate the power of this technique. It is found that both current and future radio observatories, including large arrays such as the Atacama Large Millimeter/submillimeter Array (ALMA) and the Square Kilometer Array (SKA), as well as large single dishes like the Five-hundred-meter Aperture Spherical Telescope (FAST) and the Green Bank Telescope (GBT), can explore a substantial and previously inaccessible parameter space for these dark matter candidates.
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Instrumentation and Methods for Astrophysics

A Technosignature Survey Of The Anti-Solar Point: The SETI Institute's Largest-Ever Campaign With The Allen Telescope Array

Isabel Gerrard and Sofia Z. Sheikh

The ATA-ASP campaign is a radio technosignature survey of the Anti-Solar Point as a "Schelling point", using the Allen Telescope Array (ATA) in the Search for Extraterrestrial Intelligence (SETI). We borrow from game theory the concept of Schelling points to hypothesize spacetime coordinates where both we and an extraterrestrial agent might send and search for a signal. From the perspective opposite the Sun, an extraterrestrial agent could detect Earth transiting within the habitable zone, thus this Anti-Solar Point (ASP) poses a shared and salient Schelling point. This campaign uses the ATA, tuned to 2356-3700 MHz, to observe Earth's ecliptic, and searches for sky-localized, narrowband, Doppler-drifting signals. Analysis is conducted using the Allen Telescope Survey Agnostic Technosignature pipeline (ATSAT), which integrates software packages bliss and NBeamAnalysis with radio frequency interference removal and outputs spectrograms. Narrowband signals and their Doppler-drift rates indicate technological and distant origin, while comparing beamformed beams localizes signals to the ASP. The plots are visually inspected and cataloged into six signal morphologies to distinguish potential signals-of-interest and radio frequency interference. To date, the survey has observed approximately 12% of the projected coordinate coverage over 126 observations; 67% of sessions have been analyzed, producing more than 11,000 plots, all of which have been inspected and 75% labeled. 25 of these labeled spectrograms contain narrowband drifting signals sky-localized to the ASP, and the 10 corresponding coordinates will be re-observed. Although SETI literature has long proposed searching for beacons at the ASP, this campaign provides the first observational coverage. Observing Earth's ecliptic will require a multi-year effort and produce over 11 petabytes of data, making it the ATA's largest survey ever.
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Optics

Conductivity-driven chirality in geometrically achiral plasmonic nanostructures and metasurfaces

Yulong Duan, Longzhu Liu, Suraya Kazi et al. (+7 more)

Resonant nanostructures are powerful for chiral control of light, but widely assumed to require achiral geometry. Here we demonstrate that optical chirality can emerge in geometrically achiral nanostructures, through the misalignment of independent linear responses. By rotating the conductivity tensor of an anisotropic plasmonic medium relative to a geometrically symmetric nanostructure, we generate a spin-selective optical response that can be continuously tuned both in magnitude and handedness, including reversible switching between left- and right-handed behaviour. We experimentally realize this concept using an aligned plasmonic conducting polymer and by controlling the orientation of its polymer backbone relative to otherwise identical rectangular nanoantennas. This leads to strong planar chirality that can also be reversibly modulated by varying the carrier density of the polymer. Moreover, the rotation angle of rectangular meta-atoms made through this principle encodes no longer only the local geometric phase but simultaneously the local optical chirality. This enables a new design paradigm for phase-gradient metasurfaces , enabling simultaneous control of optical chirality and wavefronts through a single rotational degree of freedom.
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All authors Yulong Duan, Longzhu Liu, Suraya Kazi, Harry Miyosi Silalahi, Roger Magnusson, Xing Xing, Zhe Zhang, Dongqing Lin, Wanlin Wang, Magnus P. Jonsson

Atmospheric and Oceanic Physics · Cross-listed from cs.LG

Skillful Data-Driven Subseasonal Soil Moisture Forecasting: Prospects and Limits for Flash Drought Prediction

Noelia Otero, Atahan Özer, Miguel-Ángel Fernández-Torres et al. (+1 more)

Despite substantial progress in short-to-medium-range weather forecasting, predicting high-impact events such as flash droughts remains a key challenge for both early warning operations and physically-based subseasonal-to-seasonal (S2S) prediction systems. Here we demonstrate that, for S2S soil-moisture forecasting over Europe, forecast skill depends as much on how the prediction problem is formulated as on the forecasting model itself. Using a Vision Transformer-based architecture with dual-pathway temporal and spatial attention, we show that residual learning is essential to outperform persistence. This advantage is realized only when forecasting root-zone soil moisture in physical units rather than standardized anomalies, revealing that the target representation itself constrains predictability. A probabilistic extension via quantile-head fine-tuning further provides well-calibrated predictive distributions. Benchmarked against deep-learning and operational ECMWF S2S baselines over 2021-2022, our model achieves the highest deterministic and probabilistic skill at all lead times and reliably detects anomalously dry root-zone states (below the 20th percentile). Yet flash drought onset, defined by multi-pentad intensification criteria, remains a fundamental challenge shared across all current S2S systems. These findings advance data-driven S2S soil-moisture forecasting while highlighting the remaining challenge of predicting rapid drought development.
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All authors Noelia Otero, Atahan Özer, Miguel-Ángel Fernández-Torres, Jackie Ma

Nuclear Experiment

Evolution of high-spin states in neutron-rich $^{195-202}$Au isotopes approaching the $N=126$ shell closure

Y. Cho, Y. H. Kim, A. Navin et al. (+48 more)

Background: The nuclear structure in the region southwest of the doubly magic $^{208}$Pb is important to benchmark theoretical models relevant for neutron-rich heavy element formation and for the origin of the $A\approx195$ peak in the mass abundance distribution. Although neutron-rich Pb, Tl, and Hg ($Z=80-82$) isotopes are relatively well studied, experimental data for neutron-rich Au isotopes ($Z=79$) remain largely limited due to experimental challenges. Purpose: The purpose of this work is to investigate the evolution of the high-spin structure in neutron-rich Au isotopes near the $N=126$ shell closure and to characterize the underlying shell-model configurations, with a particular focus on the roles of the high-$j$ unique-parity $\pi h_{11/2}$ and $\nu i_{13/2}$ orbitals. Methods: Neutron-rich $^{195-202}$Au isotopes were produced using multi-nucleon transfer reactions of $^{198}$Pt($^{136}$Xe, $^{x}$I)$^{y}$Au at a beam energy of 7 MeV/u. %between a 7 MeV/u $^{136}$Xe beam and a $^{198}$Pt target at GANIL. Prompt and delayed $\gamma$-ray spectroscopy of isotopically identified reaction products was performed with a unique experimental setup combining the VAMOS++ large acceptance magnetic spectrometer, the AGATA HPGe $\gamma$-ray tracking array, and the CATLIFE detection system.
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All authors Y. Cho, Y. H. Kim, A. Navin, M. Rejmund, A. Lemasson, D. Ramos, E. Clement, C. Yuan, M. Liu, P. van Isacker, A. N. Andreyev, J. Dudouet, S. Choi, Y. Son, A. Mukherjee, D. Ackermann, G. de Angelis, S. Bae, R. Banik, S. Bhattacharya, S. Bhattacharyya, K. Chae, F. Didierjean, C. Fougeres G. de France, G. Fremont, J. Goupil, G. M. Gu, J. Ha, K. I. Hahn, Y. Hirayama, S. Jeong, C. H. Kim, M. J. Kim, S. H. Kim, W. Korten, P. Marini, H. Miyatake, M. Mukai, G. Mukherjee, T. Niwase, T. Otsuka, J. Park, R. M. Perez-Vidal, F. Recchia, K. Rezynkina, P. Schury, J. C. Thomas, D. T. Kattikat Melcom, I. Tsekhanovich, A. Utepov, Y. X. Watanabe

High Energy Physics (Experiment)

First observation of the electromagnetic Dalitz decay $\psi(3686) \rightarrow \mu^+ \mu^- \eta^\prime$

BESIII Collaboration: M. Ablikim, M. N. Achasov, P. Adlarson et al. (+777 more)

Utilizing $(2712.4 {\pm} 14.3)\times10^{6}~\psi(3686)$ events collected by the BESIII detector at the symmetric $e^+ e^-$ collider BEPCII, we report the first observation of the electromagnetic Dalitz decay $\psi(3686) \to \mu^+ \mu^-\eta^{\prime} $ with a statistical significance of 6.1$\sigma$. The branching fraction is determined to be $\mathcal{B}(\psi(3686) \to \mu^+ \mu^- \eta^{\prime})=(4.1 \pm 1.0_{\rm stat.} \pm 0.4_{\rm syst.})\times 10^{-7}$. The ratio to the branching fraction of the radiative decay $\psi(3686) \to \gamma \eta^{\prime}$ is estimated to be $(3.3\pm0.9)\times10^{-3}$, which is consistent with the prediction of the vector meson dominance model within $1\sigma$. Furthermore, using the branching fraction of $\psi(3686) \to e^+ e^- \eta^{\prime}$ previously measured by the BESIII experiment, the ratio between the muon and the electron channels is evaluated to be $0.22\pm0.07$, which is consistent with the calculation of the vector meson dominance model within $1\sigma$, and no significant violation of lepton flavor universality is found.
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All authors BESIII Collaboration: M. Ablikim, M. N. Achasov, P. Adlarson, X. C. Ai, C. S. Akondi, R. Aliberti, A. Amoroso, Q. An, M. S. Anderson, Y. Bai, O. Bakina, H. R. Bao, X. L. Bao, M. Barbagiovanni, V. Batozskaya, K. Begzsuren, N. Berger, M. Berlowski, M. B. Bertani, D. Bettoni, F. Bianchi, E. Bianco, A. Bortone, I. Boyko, R. A. Briere, A. Brueggemann, D. Cabiati, H. Cai, M. H. Cai, X. Cai, X. K. Cai, G. F. Cao, N. Cao, S. A. Cetin, X. Y. Chai, J. F. Chang, T. T. Chang, G. R. Che, Y. Z. Che, C. H. Chen, Chao Chen, G. Chen, H. S. Chen, H. Y. Chen, M. L. Chen, S. J. Chen, S. M. Chen, T. Chen, W. Chen, X. R. Chen, X. T. Chen, X. Y. Chen, Y. B. Chen, Y. Q. Chen, Z. K. Chen, J. Cheng, L. N. Cheng, S. K. Choi, X. Chu, G. Cibinetto, F. Cossio, J. Cottee-Meldrum, H. L. Dai, J. P. Dai, X. C. Dai, A. Dbeyssi, R. E. de Boer, D. Dedovich, C. Q. Deng, Z. Y. Deng, A. Denig, I. Denisenko, M. Destefanis, F. De~Mori, E. Di Fiore, X. X. Ding, Y. Ding, Y. X. Ding, J. Dong, L. Y. Dong, M. Y. Dong, X. Dong, Z. J. Dong, M. C. Du, S. X. Du, Shaoxu Du, X. L. Du, Y. Q. Du, Y. Y. Duan, Z. H. Duan, P. Egorov, G. F. Fan, J. J. Fan, K. X. Fan, Y. H. Fan, J. Fang, Jin Fang, S. S. Fang, W. X. Fang, Y. Q. Fang, L. Fava, F. Feldbauer, C. Q. Feng, J. H. Feng, Q. X. Feng, Y. T. Feng, M. Fritsch, C. D. Fu, J. L. Fu, Y. W. Fu, H. Gao, Xu Gao, Y. Gao, Y. N. Gao, Y. Y. Gao, Yunong Gao, Z. Gao, S. Garbolino, I. Garzia, L. Ge, P. T. Ge, Z. W. Ge, C. Geng, A. Gilman, K. Goetzen, J. Gollub, J. B. Gong, J. D. Gong, L. Gong, W. X. Gong, B. Gou, W. Gradl, M. Greco, M. D. Gu, M. H. Gu, C. Y. Guan, A. Q. Guo, H. Guo, J. N. Guo, L. B. Guo, M. J. Guo, R. P. Guo, X. Guo, Y. P. Guo, Z. Guo, A. Guskov, J. Gutierrez, J. Y. Han, T. T. Han, X. Han, F. Hanisch, J. Y. Hao, K. D. Hao, X. Q. Hao, F. A. Harris, C. Z. He, K. K. He, K. L. He, F. H. Heinsius, C. H. Heinz, Y. K. Heng, C. Herold, P. C. Hong, G. Y. Hou, X. T. Hou, Y. R. Hou, Z. L. Hou, H. M. Hu, J. F. Hu, Q. P. Hu, S. L. Hu, T. Hu, Y. Hu, Y. X. Hu, Z. M. Hu, G. S. Huang, K. X. Huang, L. Q. Huang, P. Huang, X. T. Huang, Y. P. Huang, Y. S. Huang, T. Hussain, N. Hüsken, N. in der Wiesche, J. Jackson, Q. Ji, Q. P. Ji, W. Ji, X. B. Ji, X. L. Ji, Y. Y. Ji, L. K. Jia, X. Q. Jia, D. Jiang, S. J. Jiang, X. S. Jiang, Y. Jiang, J. B. Jiao, J. K. Jiao, Z. Jiao, L. C. L. Jin, S. Jin, Y. Jin, M. Q. Jing, X. M. Jing, T. Johansson, S. Kabana, X. L. Kang, X. S. Kang, B. C. Ke, V. Khachatryan, A. Khoukaz, O. B. Kolcu, B. Kopf, L. Kröger, L. Krümmel, Y. Y. Kuang, M. Kuessner, X. Kui, N. Kumar, A. Kupsc, W. Kühn, Q. Lan, W. N. Lan, T. T. Lei, M. Lellmann, T. Lenz, C. Li, C. H. Li, C. K. Li, Cong Li, D. M. Li, F. Li, G. Li, H. B. Li, H. J. Li, H. L. Li, H. N. Li, H. P. Li, Hui Li, J. N. Li, J. S. Li, J. W. Li, K. Li, K. L. Li, L. J. Li, L. K. Li, Lei Li, M. H. Li, M. R. Li, M. T. Li, P. L. Li, P. R. Li, Q. M. Li, Q. X. Li, R. Li, S. Li, S. X. Li, S. Y. Li, Shanshan Li, T. Li, T. Y. Li, W. D. Li, W. G. Li, X. Li, X. H. Li, X. K. Li, X. L. Li, X. Y. Li, X. Z. Li, Y. Li, Y. H. Li, Y. B. Li, Y. C. Li, Y. G. Li, Y. P. Li, Yi Li, Z. H. Li, Z. J. Li, Z. L. Li, Z. X. Li, Z. Y. Li, Zaiyi Li, C. Liang, H. Liang, Y. F. Liang, Y. T. Liang, Z. Z. Liang, G. R. Liao, L. B. Liao, M. H. Liao, Y. P. Liao, J. Libby, A. Limphirat, C. C. Lin, C. X. Lin, D. X. Lin, T. Lin, B. J. Liu, B. X. Liu, C. Liu, C. X. Liu, F. Liu, F. H. Liu, Feng Liu, G. M. Liu, H. Liu, H. B. Liu, H. M. Liu, Huihui Liu, J. B. Liu, K. Liu, K. Y. Liu, Ke Liu, Kun Liu, L. Liu, L. C. Liu, Lu Liu, M. H. Liu, P. L. Liu, Q. Liu, S. B. Liu, T. Liu, W. M. Liu, W. T. Liu, X. Liu, X. K. Liu, X. L. Liu, X. P. Liu, X. T. Liu, X. Y. Liu, Y. Liu, Y. B. Liu, Yi Liu, Z. A. Liu, Z. D. Liu, Z. Q. Liu, Z. X. Liu, Z. Y. Liu, Ziqiang Liu, X. C. Lou, H. J. Lu, J. G. Lu, X. L. Lu, Y. Lu, Y. H. Lu, Y. P. Lu, Z. H. Lu, C. L. Luo, J. R. Luo, J. S. Luo, M. X. Luo, T. Luo, X. L. Luo, Z. Y. Lv, X. R. Lyu, Y. F. Lyu, Y. H. Lyu, C. L. Ma, F. C. Ma, H. L. Ma, Heng Ma, J. L. Ma, L. L. Ma, L. R. Ma, Q. M. Ma, R. Q. Ma, R. Y. Ma, T. Ma, X. T. Ma, X. Y. Ma, F. E. Maas, I. MacKay, M. Maggiora, S. Maity, S. Malde, L. M. Mansur, Y. J. Mao, Z. P. Mao, S. Marcello, A. Marshall, F. M. Melendi, Y. H. Meng, Z. X. Meng, G. Mezzadri, H. Miao, T. J. Min, R. E. Mitchell, X. H. Mo, B. Moses, N. Yu. Muchnoi, J. Muskalla, Y. Nefedov, F. Nerling, H. Neuwirth, Z. Ning, S. Nisar, Q. L. Niu, W. D. Niu, Y. Niu, C. Normand, S. L. Olsen, Q. Ouyang, I. V. Ovtin, S. Pacetti, Y. Pan, C. Y. Pang, A. Pathak, Y. P. Pei, M. Pelizaeus, G. L. Peng, H. P. Peng, X. J. Peng, Y. Y. Peng, K. Peters, K. Petridis, J. L. Ping, R. G. Ping, S. Plura, V. Prasad, L. Pöpping, F. Z. Qi, H. R. Qi, L. Y. Qian, S. Qian, W. B. Qian, C. F. Qiao, J. H. Qiao, J. J. Qin, J. L. Qin, L. Q. Qin, L. Y. Qin, P. B. Qin, X. P. Qin, X. S. Qin, Z. H. Qin, J. F. Qiu, Z. H. Qu, J. Rademacker, K. Ravindran, C. F. Redmer, A. Rivetti, M. Rolo, G. Rong, S. S. Rong, F. Rosini, Ch. Rosner, M. Q. Ruan, W. R. Ruangyoo, N. Salone, A. Sarantsev, Y. Schelhaas, M. Schernau, K. Schoenning, M. Scodeggio, W. Shan, X. Y. Shan, Z. J. Shang, J. F. Shangguan, L. G. Shao, M. Shao, C. P. Shen, H. F. Shen, W. H. Shen, X. Y. Shen, B. A. Shi, Ch. Y. Shi, H. Shi, J. L. Shi, J. Y. Shi, M. H. Shi, S. Shi, S. Y. Shi, X. Shi, H. L. Song, J. J. Song, M. H. Song, T. Z. Song, W. M. Song, Zirong Song, S. Sosio, S. Spataro, S. Stansilaus, F. Stieler, M. Stolte, S. S Su, G. B. Sun, G. X. Sun, H. Sun, H. K. Sun, J. F. Sun, K. Sun, L. Sun, R. Sun, S. S. Sun, T. Sun, W. Y. Sun, Y. C. Sun, Y. H. Sun, Y. J. Sun, Y. Z. Sun, Z. Q. Sun, Z. T. Sun, H. Tabaharizato, N. T. Tagsinsit, C. J. Tang, G. Y. Tang, J. Tang, J. J. Tang, L. F. Tang, Y. A. Tang, Z. H. Tang, L. Y. Tao, M. Tat, J. X. Teng, J. Y. Tian, W. H. Tian, Y. Tian, Z. F. Tian, K. Yu. Todyshev, I. Uman, E. van der Smagt, B. Wang, Bin Wang, Bo Wang, C. Wang, Chao Wang, Cong Wang, D. Y. Wang, F. K. Wang, H. J. Wang, H. R. Wang, J. Wang, J. H. Wang, J. J. Wang, J. P. Wang, K. Wang, L. L. Wang, L. W. Wang, M. Wang, Mi Wang, N. Y. Wang, S. Wang, Shun Wang, T. Wang, W. Wang, W. P. Wang, X. F. Wang, X. L. Wang, X. N. Wang, Xin Wang, Y. Wang, Y. D. Wang, Y. F. Wang, Y. H. Wang, Y. J. Wang, Y. L. Wang, Y. N. Wang, Yanning Wang, Yaqian Wang, Yi Wang, Yuan Wang, Z. Wang, Z. L. Wang, Z. Q. Wang, Z. Y. Wang, Zhi Wang, Ziyi Wang, D. Wei, D. H. Wei, D. J. Wei, H. R. Wei, F. Weidner, H. R. Wen, S. P. Wen, U. Wiedner, G. Wilkinson, M. Wolke, J. F. Wu, L. H. Wu, L. J. Wu, Lianjie Wu, S. G. Wu, S. M. Wu, X. W. Wu, Z. Wu, H. L. Xia, L. Xia, B. H. Xiang, D. Xiao, G. Y. Xiao, H. Xiao, Y. L. Xiao, Z. J. Xiao, C. Xie, K. J. Xie, Y. Xie, Y. G. Xie, Y. H. Xie, Z. P. Xie, T. Y. Xing, D. B. Xiong, G. F. Xu, H. Y. Xu, Q. J. Xu, Q. N. Xu, T. D. Xu, X. P. Xu, Y. Xu, Y. C. Xu, Z. S. Xu, F. Yan, L. Yan, W. B. Yan, W. C. Yan, W. H. Yan, W. P. Yan, X. Q. Yan, Y. Y. Yan, H. J. Yang, H. L. Yang, H. X. Yang, J. H. Yang, L. Y. Yang, N. Yang, R. J. Yang, X. Y. Yang, Y. Yang, Y. G. Yang, Y. H. Yang, Y. M. Yang, Y. Q. Yang, Y. Z. Yang, Youhua Yang, Z. B. Yang, W. J. Yao, Z. P. Yao, M. Ye, M. H. Ye, Z. J. Ye, K. Yi, Junhao Yin, Z. Y. You, B. X. Yu, C. X. Yu, G. Yu, J. S. Yu, L. W. Yu, T. Yu, X. D. Yu, Y. C. Yu, Yongchao Yu, C. Z. Yuan, H. Yuan, J. Yuan, Jie Yuan, L. Yuan, M. K. Yuan, S. H. Yuan, Y. Yuan, C. X. Yue, Ying Yue, A. A. Zafar, F. R. Zeng, S. H. Zeng, X. Zeng, Y. J. Zeng, Yujie Zeng, Y. C. Zhai, Y. H. Zhan, B. L. Zhang, B. R. Zhang, B. X. Zhang, D. H. Zhang, G. Y. Zhang, Gengyuan Zhang, H. Zhang, H. C. Zhang, H. H. Zhang, H. L. Zhang, H. Q. Zhang, H. R. Zhang, H. Y. Zhang, Han Zhang, J. Zhang, J. J. Zhang, J. L. Zhang, J. Q. Zhang, J. S. Zhang, J. W. Zhang, J. X. Zhang, J. Y. Zhang, J. Z. Zhang, Jianyu Zhang, Jin Zhang, Jiyuan Zhang, L. M. Zhang, Lei Zhang, N. Zhang, P. Zhang, Q. Zhang, Q. Y. Zhang, Q. Z. Zhang, R. Y. Zhang, S. H. Zhang, S. N. Zhang, Shulei Zhang, X. M. Zhang, X. Y. Zhang, Y. T. Zhang, Y. H. Zhang, Y. P. Zhang, Y. P. Zhang, Yao Zhang, Yu Zhang, Yu Zhang, Z. Zhang, Z. D. Zhang, Z. H. Zhang, Z. L. Zhang, Z. R. Zhang, Z. X. Zhang, Z. Y. Zhang, Zh. Zh. Zhang, Zhaoke Zhang, Zhilong Zhang, Ziyang Zhang, Ziyu Zhang, G. Zhao, J.-P. Zhao, J. Y. Zhao, J. Z. Zhao, L. Zhao, Lei Zhao, M. G. Zhao, R. P. Zhao, Y. B. Zhao, Y. L. Zhao, Y. P. Zhao, Y. X. Zhao, Z. G. Zhao, A. Zhemchugov, B. Zheng, B. M. Zheng, J. P. Zheng, W. J. Zheng, W. Q. Zheng, X. R. Zheng, Y. H. Zheng, B. Zhong, C. Zhong, X. Zhong, H. Zhou, J. Q. Zhou, S. Zhou, X. Zhou, X. K. Zhou, X. R. Zhou, X. X. Zhou, X. Y. Zhou, Y. X. Zhou, Y. Z. Zhou, A. N. Zhu, J. Zhu, K. Zhu, K. J. Zhu, K. S. Zhu, L. X. Zhu, Lin Zhu, S. H. Zhu, W. D. Zhu, W. J. Zhu, W. Z. Zhu, Y. C. Zhu, Z. A. Zhu, X. Y. Zhuang, M. Zhuge, J. H. Zou, J. Zu

High Energy Physics (Phenomenology)

$\lambda$-$\rho$ mode mixing and radial Regge trajectories for triply heavy baryons $\Omega_{ccc}$ and $\Omega_{bbb}$ in the diquark picture

Jiao-Kai Chen, Xin-Ru Liu and Qi Liu

The mixed-mode trajectories arising from permutation-enforced $\lambda$-$\rho$ mode mixing are first investigated in the diquark picture. By accounting for the internal structure and substructure of baryons, we propose an approach to construct the mixed-mode Regge trajectories for baryons composed of three identical quarks. For triply heavy baryons $\Omega_{ccc}$ and $\Omega_{bbb}$, naive diquark-quark basis states without full permutation symmetrization violate the exchange symmetry required by the Pauli exclusion principle for three identical fermions; consequently, physical eigenstates arise as permutation-enforced $\lambda$-$\rho$ mode admixtures. Under the minimal-mixing assumption, we explicitly perform permutation symmetrization for the $J^{P}=(3/2)^{+}$ radially-excited S-wave states and construct mixed-mode Regge trajectory formulas for these symmetrized states. Unlike triply heavy baryons $\Omega_{ccb}/\Omega_{cbb}$ in the fixed diquark $(cc)b/(bb)c$ picture where well-defined pure $\rho$- and $\lambda$-trajectories exist, genuine pure-mode trajectories no longer survive for $\Omega_{ccc}$ and $\Omega_{bbb}$ due to permutation-driven cross-mode mixing. The resulting effective radial trajectories exhibit a novel sprouting-branch-like behavior. Both the original unmixed trajectories and the mixed-mode effective trajectories exhibit behavior of $M\sim x^{2/3}$ (where $x=n_r,\,N_r,\,n_r+N_r$). Radially excited masses are crudely estimated via the mixed-mode Regge trajectories, which show reasonable agreement with existing theoretical predictions.
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Soft Condensed Matter

Spontaneous Motion Generates Reversible Nonreciprocity in an Achiral Active Elastic Ring

Wen-de Tian, Kang Chen and Tianhui Zhang

Nonreciprocal mechanical response is usually associated with built-in directional couplings, structural chirality, or external driving. Whether an achiral active body can instead generate and reverse such directionality through its own motion remains less clear. Here we show that spontaneous rotation makes an active elastic ring with reciprocal passive interactions mechanically nonreciprocal. Off-center elastic forces reorient propulsion, coupling deformation back to motion. Reversing the rotation reverses the antisymmetric response, while a compensating control preserves finite directionality but strongly suppresses the near-Hopf resonance. Approaching Hopf, the selected response grows inversely with distance to onset and becomes a self-sustained traveling deformation above threshold. Thus nonreciprocity is selected by the dynamical state, while active feedback controls its critical amplification.
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Instrumentation and Methods for Astrophysics

XuYi Interferometer Observation Simulator

M. Hadjara, T. Xu, Y. Sun et al. (+21 more)

The XuYi Interferometer is the first Chinese long-baseline optical interferometer currently under development by the National Institute of Astronomical Optics and Technology (NIAOT) of the Chinese Academy of Sciences. In preparation for future scientific operations, we developed the XuYi Interferometer Observation Simulator (XIOS), a lightweight MATLAB-based software package designed to assist observers in planning interferometric observations. The simulator combines target observability calculations, interferometric baseline geometry, delay-line constraints, (u,v)-coverage prediction, and visibility estimation into a single graphical user interface. It incorporates astronomical routines from the MAAT toolbox and adopts visualization concepts inspired by ASPRO2. The software allows users to evaluate observing opportunities, predict interferometric performances, and generate realistic observing configurations before telescope operations. We present the architecture of the simulator, its principal modules, and representative simulation results obtained for the current three-telescope XuYi interferometric configuration operating in the near-infrared H band.
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All authors M. Hadjara, T. Xu, Y. Sun, W. Wei, C. Liu, H. Zhang, J. Huang, C. Zeng, J. Yuan, J. Perdigon, A. Boskri, S. Lagarde, R. Petrov, R. Ligi, B. Lopez, F. Millour, J. Dejonghe, F. Baron, J. Wang, X. Wu, H. Zhao, Y. Hou, Z. Hua, X. Cui