High Energy Physics (Phenomenology)
Pair Production of Singlet Vector-Like B Quarks in Boosted bZ Final States at a Muon Collider
Eda Alici
We investigate the pair production of singlet vector-like bottom
quarks at a future $10~\mathrm{TeV}$
muon collider in the boosted $Zb$ final-state
topology. The signal process is considered as $\mu^{+}\mu^{-}\to B\bar{B}\to (Zb)(Z\bar{b})$, with one $Z$
boson decaying leptonically and the other hadronically, leading to a final state with an opposite-sign same-flavour dilepton pair, multiple jets, and two $b$-tagged jets. Signal and Standard Model background events are generated at leading order with MadGraph5\_\allowbreak aMC@NLO and subsequently interfaced with Pythia~8 for parton showering and hadronization. Detector effects are simulated with Delphes using a
muon-
collider detector configuration. A cut-based analysis exploiting boosted kinematics, including hard leading-$b$-jet transverse momentum, small dilepton angular separation, and large hadronic activity, is performed to suppress the dominant $ZZjj$, $ZZb\bar{b}$, and $t\bar{t}$ backgrounds. Statistical sensitivities are evaluated with the Asimov approximation, including both zero and $10\%$ background systematic uncertainty scenarios. For the singlet
benchmark $\mathrm{BR}(B\to bZ)=0.25$ and an integrated luminosity of $10~\mathrm{ab}^{-1}$, a $5\sigma$ discovery reach up to $M_B\simeq 4.3~\mathrm{TeV}$ is obtained, reduced slightly to $M_B\simeq 4.2~\mathrm{TeV}$ when systematic effects are included. These results demonstrate that a $10~\mathrm{TeV}$
muon collider provides a powerful and clean environment for probing vector-like $B$
quarks well beyond present LHC limits.
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Quantum Physics
Entropic Uncertainty Relations for Mutually Unbiased Operator Frames
Jesni Shamsul Shaari and Stefano Mancini
We develop an operator-frame formulation of entropic uncertainty relations in the
Hilbert-Schmidt space of operators. For general continuous indexed operator frames, we derive an entropic uncertainty relation for the associated coefficient distributions by combining endpoint norm estimates with Riesz-Thorin interpolation. We then identify a distinguished class of mutually unbiased operator frames, defined through constant-modulus trace overlaps. Under suitable structural conditions, the corresponding coefficient amplitudes are related by a bilinear
Fourier transform, leading to a stronger Hirschman-Beckner-type entropic uncertainty relation. As canonical realizations, we consider Weyl displacement operators and Wigner kernels, as well as Cartesian dyadic frames generated by position and momentum eigenstates. These examples recover familiar continuous-variable
Fourier dualities while extending entropic uncertainty relations beyond measurement outcomes to operator representations themselves.
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Mesoscale and Nanoscale Physics
Rotating Zeeman field as a tool for Majorana zero mode detection in topological superconducting wire
Piotr Stefański
We demonstrate that analysis of the
spin polarization of a
quantum dot (QD) attached to the topological wire can provide valuable insights into Majorana zero mode (MZM) formation and topological phase transition. Detection is realized by rotation of the Zeeman field in the wire, while retaining the Zeeman field direction in the dot intact. In the presence of Majorana mode, the effective QD
spin polarization at
Fermi energy changes significantly when the direction of the Zeeman field in the wire changes from parallel to perpendicular to the wire axis. It can be opposed to the wire in its trivial state, when
spin polarization remains practically constant while the
magnetic field is rotated. Similar unaltered
spin polarization is observed when QD
spin sub-level at
Fermi energy mimics MZM. Moreover, the characteristic non-linear dependence of the
spin polarization on the
magnetic field magnitude at its critical value identifies a topological phase transition in the wire. This feature is observed independently on the coupling strength of the wire to the dot and the angle of the Zeeman field.
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High Energy Physics (Phenomenology)
Signatures of gravity-mediated dark matter interaction in theories with large extra dimensions
A. Clarke, V. V. Flambaum, M. Pospelov et al. (+1 more)
Dark matter particles that couple to the Standard Model only through
gravity are usually regarded as inaccessible to laboratory detection. This expectation can change in theories with $n$ extra spatial dimensions, where
gravity is enhanced at short distances and the potential scales as $1/r^{1+n}$. We reconsider the
gravity-mediated dark matter (DM) interactions in Arkani-Hamed-Dimopoulos-Dvali (ADD) models with $n$ large extra dimensions. The cumulative exchange of the gravitational Kaluza-Klein (KK) modes leads to the effective strength of interactions with the Standard Model nucleons that scales as $m_pm_\chi M_*^{-4}$, where $ m_\chi$ is the mass of DM and $M_*$ is the fundamental $4+n$ dimensional mass scale. We confront this interaction with sensitivity achieved in the large Xe-based underground direct detection experiments and derive bounds on the $\{m_\chi,M_*\}$ parameter space that stretches all the way to $M_*\sim$ few TeV. We also address the indirect detection of scalar $\chi$ that can resonantly annihilate via the on-shell KK modes into the SM particles $W^\pm,Z,h$. The annihilation cross section for the process scales as $\langle\sigma v\rangle \sim m_\chi^nM_*^{-n-2}$, and stringent limits on the same parameter space can be derived from observations of high-energy
galactic $\gamma$ rays.
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All authors A. Clarke, V. V. Flambaum, M. Pospelov, I. B. Samsonov
Optics
Silicon Ring Based 64$\times$100 GHz Wavelength Division Multiplexing filter
Q. Deng, A. Elshazly, M. Oktay et al. (+17 more)
Silicon-based wavelength division multiplexing (WDM) filters are essential for scaling optical communication capacity in data centers and telecommunications networks.However, extending silicon WDM systems beyond 32 channels with 100 GHz spacing poses significant challenges due to limitations in conventional filter architectures. Here we present the first silicon 64$\times$100 GHz WDM filter by introducing a novel ring-Mach-Zehnder interferometer (MZI) cascade architecture. Our design utilizes third-order
polynomial interconnected circular (TOPIC) bends to construct low-loss half-ring waveguides, facilitating an MZI configuration where the arm length difference is determined entirely by half of the ring structure. This approach ensures precise
alignment between the MZI interference peaks and the ring resonator wavelengths, with the MZI FSR being exactly double that of the ring, eliminating the need for dynamic tuning between the MZI and the ring. We demonstrate the concept through a 16$\times$400 GHz WDM filter with insertion loss of 1.3$\pm$0.6 dB and channel isolation $\geq$14.3 dB. The 64$\times$100 GHz implementation, realized using a 4-channel interleaver followed by four 16$\times$400 GHz WDM filter, achieves insertion loss of 3.2$\pm$1.1 dB and channel isolation $\geq$10.7 dB. This work opens new possibilities for high-density silicon photonic WDM systems, addressing the growing bandwidth demands of artificial intelligence and machine learning applications.
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All authors Q. Deng, A. Elshazly, M. Oktay, J. De Coster, R. Magdziak, C. Marchese, G. Lepage, D. Bode, H. Kobbi, H. K. Tyagi, J. R. Vaskasi, M. E. Filipcic, H. Sar, M. Chakrabarti, D. Velenis, P. Verheyen, P. Absil, F. Ferraro, Y. Ban, J. Van Campenhout
High Energy Physics (Experiment)
Recent Hadron Spectroscopy Results from the Belle and Belle II experiments
Elisabetta Prencipe
The Belle~II experiment, the major upgrade of the Belle detector, is currently collecting data at the SuperKEKB asymmetric-energy $e^+e^-$
collider in Tsukuba, Japan. With an integrated luminosity of 575\,fb$^{-1}$, Belle~II has already surpassed the maximum luminosity accumulated by both BaBar and Belle. Recent analyses combining Belle and Belle~II data sets have delivered results of unprecedented precision, demonstrating the strong potential of the unified data sample, which now exceeds 1.5\,ab$^{-1}$. In this contribution, recent advances in
hadron spectroscopy are presented. Highlights include new results in bottomonium and charmonium physics, with particular emphasis on the structure of the $\Upsilon(10753)$, searches for hidden-charm and hidden-strangeness pentaquarks, and the latest developments in
baryon spectroscopy, including studies of the $\Omega(2012)$ and excited $\Lambda_c$ states. Prospects for future spectroscopy analyses exploiting the full Belle and Belle~II data sets are also discussed.
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Nuclear Experiment
Single Particle Excitations, Band Structures and Octupole Correlation in $^{65}$Zn
Anil Sharma, S. Nandi, S. S. Dutta et al. (+15 more)
The excitation scheme of the $^{65}$Zn ($Z = 30, N = 35$)
nucleus has been probed following its population in the $^{63}$Cu($\alpha$,pn) reaction at E$_{beam}$ = 30 MeV and using an array of Compton suppressed HPGe clovers as the detection system. This work has identified several new transitions of the
nucleus and have modified the placements of some of the previously known ones. The multipolarities and the electric/
magnetic nature of the observed $\gamma$-ray rays have been measured, using the conventional methodologies. The
spin-parity assignments for the levels have consequently been made; some of the
spin-parities are new while others are either validation of the existing values or are modified results based on the present analysis. The experimental level scheme exhibits collective as well as single particle structures. The measured level energies have been compared with those calculated in the framework of the large basis shell model using a model space of $p_{3/2}, f_{5/2}, p_{1/2}, g_{9/2}$ orbitals and two different interactions. The collective excitations of the
nucleus were probed through the properties of its band structures and through the calculations of the Total Routhian Surface (TRS) for the associated deformations/ shapes. The results of this study brings out the essential features of evolving structural characteristics and developing collectivity with increasing number of nucleons outside a doubly-magic core and with their occupancy of deformation driving high-$j$ orbitals.
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All authors Anil Sharma, S. Nandi, S. S. Dutta, S. Kundu, Pankaj K. Giri, A. Das, S. S. Ghugre, S. S. Nayak, S. Basu, S. Pal, S. Das, S. Dar, S. Paul, A. Pal, S. Basak, G. Mukherjee, S. Bhattacharyya, R. Raut
Earth and Planetary Astrophysics
Thermal and rotational effects of giant impacts during terrestrial planet accretion
Adriana N. Postema, Simon J. Lock and Sarah T. Stewart
Terrestrial
planets likely experienced one or more
giant impacts during their formation that inflicted large thermal, chemical, and rotational perturbations. The early states of terrestrial
planets are expected to be dominated by the thermal and rotational outcomes of
giant impacts, but critical parameters that control internal processes, such as the pressures and temperatures of core formation, are not fully understood. Here we present the results from a representative suite of collisions between Moon- to super-Earth-mass bodies using the SWIFT hydrocode and updated ANEOS equations of state, allowing more robust temperature calculations. Using these results and the HERCULES planetary structure code, we calculated the contributions from thermal energy, gravitational potential energy, and post-impact rotation on the pressure-temperature conditions of the core-mantle boundary (CMB). We derived scaling laws for the efficiency of impact heating, mantle-core heat partitioning, and CMB pressures and temperatures. We find that post-impact CMB pressures are generally lower than previously assumed, due to both thermal and rotational effects. Full mantle melting is common and a substantial fraction of mantle material is heated above the Fe-MgO solvus closure temperature for impacts with modified specific energies $Q_S>10^6$ J/kg, implying that a miscible layer could form close to the CMB for many
giant impacts. The comparatively low internal pressures and large regions of metal-silicate miscibility after
giant impacts have significant effects on the processes of core formation, and our work indicates that metal-silicate equilibration would occur near the CMB during later post-impact cooling, consistent with Earth's geochemistry.
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Exactly Solvable and Integrable Systems
Bihamiltonian structure of the $(n,1)$-type rational reductions of the 2D-Toda hierarchy
Haonan Qu and Qiulan Zhao
We derive a local bihamiltonian structure for the rational reduction of the 2D-Toda hierarchy (RR2T) of $(n,1)$-type by direct computations, and construct an $(n+1)$-dimensional semisimple generalized Frobenius
manifold with non-flat unity whose Principal Hierarchy contains its dispersionless flows.
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Materials Science · Cross-listed from cs.LG
Substitution-Based Analysis of Structural Novelty for Generative Models of Materials
Masahiro Negishi and Aron Walsh
There has been rapid progress in generative artificial intelligence (AI) models for inorganic
crystal design, which can efficiently generate large numbers of candidate compounds after being trained on databases of known
crystals. However, it remains unclear whether they genuinely expand the accessible materials search space beyond conventional strategies such as elemental substitution within known structure types. We address this question by developing a workflow to assess whether AI-generated
crystals are duplicates of training structures, reproducible by elemental substitution, or unmatched by either criterion. Applying this workflow to representative generative models reveals that 81-92% of chemically valid and metastable generated
crystals are either training duplicates or substitution-derived structures. This tendency is particularly strong in high-
symmetry crystal systems, even though many possible structural prototypes remain unexplored. Further analysis of the underlying structural fingerprints shows that low-
symmetry structures beyond duplication or substitution can be interpreted as interpolation in training-data-rich regions, while high-
symmetry duplicates appear to result from memorisation in training-sparse regions. Our findings highlight a limitation in the current generation of models that exhibit a bias towards known structural prototypes in the high
symmetry regions, but enable wider exploration of the low-
symmetry structural space.
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Materials Science
Toward in-situ/operando X-ray absorption spectroscopy and electrochemical characterization of solid oxide fuel cells
Renato A. N. de Oliveira, Rafael Galiza Yoshimura, Liliana Mogni et al. (+15 more)
The focus of the present work is the development of specialized experimental instrumentation compatible with synchrotron characterization for in-situ and operando symmetric intermediate temperature solid
oxide fuel
cells (IT-SOFC) studies at maximum temperatures of 800 C , exposed to reducing and oxidizing atmospheres, using fluorescence X-ray absorption spectroscopy (XAS) measurements in combination with electrochemical impedance spectroscopy (EIS) in the multipurpose Quati beamline at CNPEM/SIRIUS synchrotron facility [1]. Symmetric IT-SOFC are gaining importance due to their structural simplicity, as they allow for the use of identical materials on both sides of the fuel
cell electrolyte; the anode, and the cathode [ 2,3 ]. The symmetric configuration opens new opportunities for fundamental research of electrode materials and improves the versatility of SOFC electrochemical devices [2,3].
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All authors Renato A. N. de Oliveira, Rafael Galiza Yoshimura, Liliana Mogni, Maurico Arce, Diego G. Lamas, Lucia Toscani, Maria Belén Arcentales Vera, Esteban Elvis Asto Ramos, Magna Monteiro Schaerer, Celeste Z.A. Aquino, Marcia Carvalho de Abreu Fantini, Taofeeq Oladayo Bello, Tereza da Silva Martins, Danilo Waismann Losito, James Moraes de Almeida, Valeria Spolon Marangoni, Leopoldo Suescunand, Santiago Figueroa
Optics · Cross-listed from cs.ET
General-Purpose Nonlinear Function Approximation via Linear Integrated Photonics
Ayana Mizuno, Isamu Takai, Makoto Nakai et al. (+3 more)
Photonic computing has emerged as a promising platform for accelerating artificial intelligence workloads by enabling low-latency and energy-efficient linear operations such as vector-
matrix multiplication. However, scalable on-chip high-order nonlinear processing remains challenging, limiting the functional versatility of current photonic hardware. Here, we present an optoelectronic approach for approximating high-order and high-dimensional nonlinear functions. The key to this approach lies in optical random
Fourier feature mapping, which transforms nonlinear function evaluation into an equivalent linear computation. This approach enables nonlinear computing within a linear photonic framework, eliminating the need for complex optical nonlinear or active materials while preserving scalability and computational throughput in a simple silicon photonic
circuit. We experimentally demonstrate a broad class of nonlinear functions, including tenth-order Legendre
polynomials, computationally demanding special functions (Voigt,
Fermi-Dirac, and Fresnel), neural-network activation functions, two-dimensional nonlinear functions, and a 10-dimensional softmax layer. This work establishes a general and scalable strategy for nonlinear computing in photonic integrated hardware and opens a pathway toward fully functional optical accelerators for next-generation computing systems.
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All authors Ayana Mizuno, Isamu Takai, Makoto Nakai, Atsutaka Miyamichi, Ryuichi Konishi, Satoshi Sunada
High Energy Astrophysical Phenomena
On the assessment of the disk truncation and detection of type-II-like bursts from the accreting millisecond X-ray Pulsar IGR J17062-6143
Aditya Sow Mondal, Mahasweta Bhattacharya, Swarnendu Jana et al. (+2 more)
We present a spectral analysis of the NuSTAR and NICER observations of the accreting millisecond X-ray
pulsar IGR J17062-6143, performed in 2022. The source remained in the hard spectral state during these observations, with a luminosity of about $\sim$0.13-0.14 percent of the Eddington luminosity. The continuum emission of the NuSTAR spectrum is entirely dominated by a power-law component or by Comptonized emission of disc
photons by a
plasma with a high electron temperature ($\gtrsim100$ keV). The NuSTAR spectrum also reveals clear evidence of disc reflection, a broad Fe K line around 6-8 keV, and a Compton hump peaking at 20 keV, irrespective of the choice of the continuum models. Our spectral studies suggest a disk extending close to the
neutron star surface ($\sim$6-20 $R_{\rm g}$) at low inclination angle ($\sim41$ degrees), as revealed by the self-consistent relativistic reflection model, relxill. In addition, we detected type-II-like bursts for the first time in the NICER observation of this source. Light curve profiles of type-II-like bursts exhibit different patterns, mostly associated with the so-called mode-0 and transition from mode-0 to mode-1 type-II bursts. The energy spectra of the persistent (pre-burst) and burst emission are well described by an absorbed Comptonization component, scattering disk- and blackbody-distributed
photons, respectively, by a corona with a temperature of 1-3 keV. Although the origin of the type-II-like burst is not very clear, it has been possibly linked to disk-magnetosphere interaction of the
accretion flow.
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All authors Aditya Sow Mondal, Mahasweta Bhattacharya, Swarnendu Jana, Biplab Raychaudhuri, Gulab C. Dewangan
Atomic Physics
An Al$^+$ clock with $1.6\times10^{-18}$ systematic uncertainty and its frequency ratios
Fabian Dawel, Johannes Kramer, Derwell Drapier et al. (+15 more)
Advances in optical clocks motivate a redefinition of the second, requiring rigorous evaluations of systematic uncertainties and robust consistency among the clocks. Here, we report the full evaluation of the systematic frequency shifts of an $^{27}\mathrm{Al}^+$ single-ion clock, and the measurement of its absolute frequency and frequency ratio with a $^{87}$Sr optical
lattice clock at PTB. The evaluated total systematic fractional frequency uncertainty is $1.6\times10^{-18}$, mainly limited by the accuracy of the relevant atomic coefficients and by background gas collisions. The absolute frequency of the clock has been measured to be $\nu_{\mathrm{Al}^+}=1 121 015 393 207 859.19(24)\,$Hz, obtained by comparison with two primary caesium fountain clocks at PTB. The frequency ratio between the Al and Sr optical clocks has been determined to be $\nu_{\mathrm{Al}^+}/\nu_{^{87}\mathrm{Sr}}=2.611 701 431 781 462 668(36)$, limited by the accuracy of the Sr clock. This ratio differs by $8.6\sigma$ and $1.2\sigma$ from the 2021 and 2025 frequency ratio published by the BACON collaboration, respectively. These results represent an important contribution toward a future redefinition of the second using optical clocks, and underscore the importance of independent measurements of clock-candidate frequency ratios across different institutions.
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All authors Fabian Dawel, Johannes Kramer, Derwell Drapier, Lennart Pelzer, Kai Dietze, Mirza A. Ali, Marek Hild, Vincent Barbé, Steven A. King, Joshua Klose, Kilian Stahl, Johannes Rahm, Navraj Poudel, Sören Dörscher, Stefan Weyers, Erik Benkler, Christian Lisdat, Piet O. Schmidt
Optics
Double-slit optical ventriloquism: High phase sensitivity via diffraction patterns
Merav Kahn, John C. Howell and Nadav Katz
High-sensitivity phase sensing is traditionally performed using complex interferometric configurations. As an alternative, we present a robust and simple system based on the classical Young's double-slit experiment that leverages the "optical ventriloquism" effect to amplify phase signals. This phenomenon arises from super-oscillations near intensity minima, which cause an anomalous shift of the local wave vector as a consequence of weak-value behavior. In this work, we constructed an accessible experimental setup that translates minute phase differences into measurable spatial displacements of the diffraction pattern. We compare the detection performance of an sCMOS camera and a quadrant-
cell detector, analyzing the noise sources that limit the system's sensitivity. Our results demonstrate that engineering the dark regions of simple diffraction patterns can provide a foundation for advanced optical sensing technologies with minimal structural complexity.
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Pattern Formation and Solitons
Financial Frequency Combs
Madhurendra Mishra, Armaan Aryan, Arsh Gogia et al. (+1 more)
Frequency combs are discrete, equally spaced, phase-coherent spectral lines that emerge from nonlinear mode coupling in physical systems. We show that the incommensurate fractional-order financial model of Huang, Li, Ma, and Chen, whose Caputo derivatives encode macroeconomic long-range
memory, generates an analogous structure in its steady-state spectrum. The comb appears only over specific values and ranges of the saving amount $a$, the investment cost $b$, and the demand elasticity $c$, outside which the spectral lines lose their equal spacing. It persists across extended parameter regimes and stays invariant to perturbations in the initial interest rate $x_0$ and investment demand $y_0$, while distinct spectral regimes appear at different initial price levels $z_0$. The comb is generated only when the fractional-order exponents $q_1$, $q_2$, and $q_3$ associated with interest rate, investment demand, and price index are above the critical threshold values. At even higher values of these exponents, the frequency comb transitions into chaos. These findings show that the long-run cyclic structure of a
memory-bearing financial economy organises into a discrete, deterministic spectral fingerprint rather than a
stochastic continuum.
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All authors Madhurendra Mishra, Armaan Aryan, Arsh Gogia, Adarsh Ganesan
Materials Science
Unconventional topological Hall response and anisotropic magnetotransport properties of a helical magnet EuAuAs
Anyesh Saraswati, Koyendrila Debnath, Shubhankar Roy et al. (+3 more)
Topological magnets with nontrivial
spin texture have attracted considerable interest because they display a rich spectrum of emergent
quantum phenomena. Here, we present a combined experimental and theoretical investigation of the
magnetic and magnetotransport properties of EuAuAs, an antiferromagnet with Néel temperature ($T_\mathrm{N}$) $\sim$ 6 K. The temperature and
magnetic field dependence of electrical resistivity and magnetization demonstrate that the charge transport in EuAuAs is strongly influenced by the
spin configuration of local Eu moments. Below $T_\mathrm{N}$, both longitudinal magnetoresistance (LMR) and transverse magnetoresistance (TMR) are positive at low fields but large and negative at high fields. With increasing temperature, TMR becomes positive above 60 K, whereas LMR remains negative up to 100 K. The low-field positive LMR and TMR originate from weak antilocalization (WAL). The WAL contribution in TMR is well captured by the Hikami-Larkin-Nagaoka model, whereas the LMR data are described by a generalized Altshuler-Aronov framework. Moreover, we observe a
giant topological
Hall effect arising from the scalar
spin chirality, which is further supported by the helical
magnetic structure obtained from the ab-initio calculations. The observed anisotropy in longitudinal resistivity and magnetoresistance underscores the very nature of the
Fermi surface of the EuAuAs, as confirmed by first-principles calculations. These results establish EuAuAs as a unique platform for exploring the interplay between electronic structure and noncoplanar
spin texture in a centrosymmetric helical magnet.
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All authors Anyesh Saraswati, Koyendrila Debnath, Shubhankar Roy, Barun Ghosh, Nitesh Kumar, Prabhat Mandal
Earth and Planetary Astrophysics
Resonance and Stochastic Dynamics of Interplanetary Dust
Minli Qiu and Phil Arras
We study the motion of
dust particles inspiraling from distant
dust reservoirs toward a close-in planetary system, including the combined effects of radiation pressure and Poynting-Robertson (PR) drag. As
dust particles migrate inward, they can be trapped in mean motion resonances (MMRs) depending on the competition between the
planet's
gravity and PR drag. Our goals are to understand the conditions under which particles can be trapped in MMRs, the
evolution in and eventual escape from resonance, and the fraction of
dust particles which will hit the planetary upper atmosphere, seeding it with heavy elements. Low-order eccentricity expansions of the disturbing function break down, so we employ an exact, rapid-phase–averaged disturbing function to determine resonant
equilibrium points and their stability. We derive analytic expressions for the growth rate of dissipative
equilibrium points and confirm that librations are generically overstable in important low-order resonances such as $3\!:\!1$, $2\!:\!1$, and $3\!:\!2$, implying that resonant capture is ultimately temporary and
dust particles escape over a wide range of
planet masses and
dust size. After resonance escape, the
dust orbit is
planet-crossing and its subsequent
evolution is intrinsically
stochastic, governed by repeated close encounters that produce random gravitational kicks. We develop an analytic, epicycle-based scattering model to derive the impact parameter distribution $P(b)$ and the resulting energy change distribution $P(\Delta x)$. Using these encounter distributions, we construct a Monte Carlo method that predicts the fractions of
dust particles that collide with the
planet, sublimate near the
star, or are ejected. Comparison of the Monte Carlo calculations with orbit integrations shows good agreement across the cases studied.
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Materials Science
Reduced-Order Modelling of Defect Transport using Surrogate Kinetics: Application to U$_x$Pu$_ {1-x}$N
Peter Hatton
Defect transport in chemically disordered materials is a difficult phenomenon to model since migration energetics depend strongly on the local chemical environment, producing a distribution of transition barriers that cannot be exhaustively enumerated. Here, we develop a reduced-order approach to modelling defect
diffusion in compositionally complex materials using environment-dependent surrogate kinetics. Migration energetics for actinide vacancies, nitride vacancies, and actinide-nitride divacancies in U$_x$Pu$_{1-x}$N are generated using the Hop-Decorate workflow across thousands of chemical configurations. These data are distilled into compact surrogate functions that predict migration barriers and energy differences from simple descriptors based on local coordination counts. The surrogate models reproduce the atomistic
dataset with low error and enable efficient evaluation of migration rates during
lattice kinetic Monte Carlo simulations. Long-time diffusivities computed across temperature and composition reveal strongly non-linear behaviour arising from two dominant mechanisms: species-controlled migration on the actinide sublattice and environment-dependent trapping on the nitride sublattice. Although demonstrated for U$_x$Pu$_{1-x}$N the framework provides a general and computationally efficient approach for modelling defect transport in chemically disordered materials and for integrating atomistic kinetics into higher-scale simulations.
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Strongly Correlated Electrons
Angular-time evolution and edge-spin dynamics in the Haldane phase of the S=1 bilinear-biquadratic chain
Takuma Kaise and Kouichi Okunishi
We investigate the angular-time
evolution – a parameter-time
evolution generated by the
entanglement Hamiltonian – for the bipartitioned ground state of the S=1 bilinear-biquadratic chain under the open boundary condition with the up edge
spin. Using a
matrix-product-state representation of the ground-state wavefunction, we calculate the angular-time
spin correlation functions $\langle S_n^{\alpha }(\tau )S_{n'}^{\alpha }(0)\rangle$ in the Haldane phase, and extract its dominant oscillation mode attributed to the nearly two-fold-degenerate
entanglement spectrum associated with the $\mathbb{Z}_2 \times \mathbb{Z}_2$
symmetry. We also compute the effective edge-
spin dynamics under a uniform
magnetic field applied to the system part and numerically verify its correspondence to the dominant angular-time mode by precisely comparing the subsystem-size dependence of their amplitudes.
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Plasma Physics
Observation of stopping power reduction at strong ion-plasma coupling
Yun Liu, Jieru Ren, Zhigang Deng et al. (+30 more)
Ion stopping in dense
plasma is crucial for
stellar evolution and fusion ignition. However, its behavior in the strong ion-
plasma coupling regime beyond the linear limit has long remained elusive, due to formidable experimental challenges. Here we report the first experimental investigation of ion stopping at an unprecedented coupling parameter exceeding unity, achieved by sending
laser-accelerated short-pulse and intense quasi-monoenergetic carbon ions ($\sim$583 keV/u, C$^{5+}$) into a uniform, long-lived, well-characterized dense
plasma target ($T_e$ $\approx$ 17 eV, $n_e$ $\approx$ 4$\times$10$^{20}$ cm$^{-3}$). By simultaneously measuring ion energy loss and charge-state
evolution, we eliminated key experimental ambiguities arising from charge-state determination. Our results clearly show a reduction in stopping power compared with predictions from standard linear dielectric response or binary collision models, and they agree well with the hybrid calculation of molecular dynamics with
quantum corrections. The importance of nonlinear screening effects arising from many-body interactions and
quantum effects due to the wave nature of electrons was demonstrated at strong coupling. This work establishes a definitive high-fidelity experimental
benchmark for collisional dynamics in the strong-coupling regime. It offers critical insight for accurate modeling of energy transport in inertial confinement fusion and astrophysical
plasmas.
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All authors Yun Liu, Jieru Ren, Zhigang Deng, Wei Qi, Bubo Ma, Wenqing Wei, Shizheng Zhang, Xuyang Luo, Ziqian Zhao, Mingzhe Yang, Yifang Gao, Xueguang Ren, Jianxing Li, Dieter H. H. Hoffmann, Xing Wang, Zhongfeng Xu, Shaoyi Wang, Quanping Fan, Bo Cui, Weiwu Wang, Sixin Wu, Yue Yang, Zhurong Cao, Zongqing Zhao, Yuqiu Gu, Leifeng Cao, Bin He, Shaoping Zhu, Olga Rosmej, Rui Cheng, Guoqing Xiao, Weimin Zhou, Yongtao Zhao
Astrophysics of Galaxies
RAD@home discovery of a bow-and-arrow radio galaxy tracing a ~560 kpc bow-shock structure in a multi-halo environment
Ananda Hota, Pratik Dabhade, Shubhrangshu Ghosh et al. (+9 more)
We report the RAD@home citizen science discovery of a unique bow-and-arrow-shaped
radio galaxy (BAARG; RAD J104501.6+352852, z = 0.159) identified in LoTSS DR2. The source exhibits striking asymmetry: on the western side, a narrow jet feeds a sector-shaped emission region at ~115 kpc, extending backward to form a ~560 kpc arc-like structure; on the eastern side, the jet develops an S-shaped distortion extending to ~250 kpc, followed by a faint, offset tail reaching ~600 kpc. Our analysis shows that the host resides in a dynamically complex, multi-
halo environment with nearby cluster-scale systems at similar
redshifts. The observed morphology is consistent with interaction between the
radio plasma and the surrounding medium, influenced by large-scale environmental gradients and bulk motions. The western structure is consistent with compression of
radio plasma near a bow-shock-like feature, possibly linked to supersonic motion of the infalling host
galaxy and its circumgalactic medium. This possibly represents one of the first instances in which morphology and environment together suggest signatures of infall- or shock-related processes; surveys such as LoTSS DR3 may reveal similar systems, offering new insights into the interplay between
radio galaxies and their large-scale environments.
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All authors Ananda Hota, Pratik Dabhade, Shubhrangshu Ghosh, Pranim Limbo, C. Konar, Sagar Sethi, Souvik Manik, Aditya Sahasranshu, Sabyasachi Pal, Mitali Damle, Sravani Vaddi, Arundhati Purohit
Earth and Planetary Astrophysics
A decade of monitoring the HIP 41378's planetary system
S. Grouffal, A. Santerne, X. Dumusque et al. (+32 more)
Multi-planetary systems provide key constraints on
planet formation and
evolution, as their architecture encodes the dynamical history of
planets formed within a common protoplanetary disk. However, the current population remains strongly biased toward compact, short-period systems, and only a limited number of such systems with measured masses and radii are known. HIP 41378 is an exceptional system hosting five transiting
planets with orbital periods up to 1.5 years, including an ultra-low density
planet HIP 41378 f. The outer transiting
planets d and e remained poorly constrained with unknown periods and masses, leaving the system architecture only partially characterised. We present long-term monitoring of this target with high-precision radial-velocity (RV) instruments (HARPS, HARPS-N, HIRES, and ESPRESSO) and space-based photometry spanning 2015-2024. We detect RV signals for all the
planets, confirming their orbital periods and constraining their masses. In particular, the RV data strongly favour an orbital period of Pd = 278 days for
planet d and refine the orbital period of
planet e to Pe = 393+3-5 days. We measure a new mass of Mf = 25 \pm 5 earth masses for HIP 41378 f, confirming its super-puff nature with a bulk density of 0.166+0.033-0.036 g cm3. We also confirm the planetary nature of HIP 41378 g, a non-transiting
planet with a 63-day period, and determine its minimum mass. In addition, the RVs reveal a long-period signal, with P = 2602+468-433 days, which we attribute to the candidate
planet HIP 41378 h, although a
stellar magnetic cycle cannot be excluded. Finally, we investigate the system's dynamical architecture and resonant structure, assess its completeness by constraining additional undetected
planets, and discuss the implications for the origin and internal structure of the remarkable
planet HIP 41378 f.
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All authors S. Grouffal, A. Santerne, X. Dumusque, B. Akinsanmi, T. Guillot, N. C. Hara, A. Leleu, L. Malavolta, M. Saillenfest, D. J. Armstrong, S. C. C. Barros, D. Bayliss, A. S. Bonomo, D. J. A. Brown, A. Collier Cameron, M. Cretignier, I. J. M. Crossfield, F. Dai, M. Damasso, O. Demangeon, P. Figueira, P. Leonardi, A. F. Martinez Fiorenzano, M. Lopez-Morales, E. Molinari, A. Mortier, L. D. Nielsen, H. P. Osborn, E. Petigura, K. Rice, N. C. Santos, A. Sozzetti, S. Sulis, S. Udry, C. Watson
Quantum Physics
Understanding Squeezed States of Light Through Wigner's Phase-Space
Sibel Baskal and Marilyn E. Noz
This paper starts with the transition from classical physics to
quantum mechanics which was greatly aided by the concept of phase space. The role of canonical transformations in
quantum mechanics is addressed. The Wigner phase-space distribution function is then defined which arises from the formulation of the density
matrix, followed by the harmonic oscillator in phase space. Coherent and one- and two-mode squeezed states of light as well as the squeezed
vacuum are discussed in the phase-space picture.
Attention is also drawn to the fact that squeezed states naturally generate
entanglement between the two-modes. Coupled harmonic oscillators are also elucidated in connection with the Wigner phase space. It will be noted that the phase-space picture of
quantum mechanics has become an important scientific
language for the rapidly expanding field of
quantum optics. Here, we mainly focus on the simplest form of the Wigner function, which finds application in many branches of
quantum mechanics. We make use of several
symmetry groups such as Lorentz groups, the
symplectic group in two and four dimensions, and the Euclidean group. The decoherence problem of an optical field is examined through a reformulation of the Poincaré sphere as a further illustration of the density
matrix.
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Medical Physics
A Positron Range Correction with Texture Preservation Framework in PET Imaging
Nerea Encina-Baranda, Yifan Zheng, Jorge Cabello et al. (+5 more)
Positron range (PR) blurring is a fundamental resolution limitation in PET imaging with high-energy positron emitters such as 82Rb, causing contrast loss and spill-out effects across heterogeneous tissue interfaces. We propose PRC-TP, a positron range correction (PRC) framework with explicit texture preservation that decouples deterministic resolution recovery from
stochastic texture restoration. A nnFormer-based neural network (NN) was trained on patient-derived Monte Carlo simulations to map PR-degraded 82Rb reconstructions to PR-free references using attenuation maps as anatomical context. However, this NN also significantly removed the noise in the images, which could impact some texture analysis methods or make the images look unrealistic. An auxiliary Noise2Noise model estimates that smoothing effect, enabling texture extraction and transfer to the PR-corrected prediction through Model-consistent Texture Re-Injection (MTRI). In simulated patients, PRC-TP preserved contrast recovery close to ground truth (GT) (98.96-99.04%) while restoring noise and CNR closer to the reference. The function-based MTRI formulation achieved near unity global texture amplitude agreement with GT (0.997 +/- 0.011), reducing the input texture amplitude bias (0.951 +/- 0.011). Radiomics analysis showed improved agreement with GT across texture-sensitive feature families. A clinical 82Rb evaluation showed trends consistent with simulations, including comparable contrast-ratio increase (10.18% vs. 10.99%) and restoration of texture suppressed by PRC. These results support PRC-TP as a practical framework for resolution recovery with acquisition-consistent texture preservation in PET imaging. Submitted to IEEE TRPMS.
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All authors Nerea Encina-Baranda, Yifan Zheng, Jorge Cabello, Robert. J. Paneque-Yunta, Cindy. M. Solano-Cordero, Alejandro Lopez-Montes, Maurizio Conti, Joaquin. L. Herraiz
Mesoscale and Nanoscale Physics
Fingerprints of an Imbert-Fedorov-like effect in the tunneling transmission of Rarita-Schwinger semi-metals
Otman Bouladiane, Ahmed Jellal, Hocine Bahlouli et al. (+2 more)
We study tunneling through a square barrier in a rotationally symmetric Rarita-Schwinger semi-metal and identify fingerprints of an Imbert-Fedorov-like effect in the tunneling transmission. The problem is intrinsically multichannel at all energies because there exist two propagating sectors with
spin projections $m=1/2$ and $m=3/2$. We derive the transmission amplitudes analytically and compare the single-channel and coherent mixed-incidence cases in the two channels. Interestingly, we observe that tunneling at high energy shows a bias towards scattering into
spin projection $3/2$ contributions. For single-channel injection, we find that the transmission remains symmetric under a mirror transformation of the incident angle. In contrast, for the coherent superposition, we find a directional asymmetry in the transmission probability $T(k_y)\neq T(-k_y)$. Importantly, this effect does not originate from an anisotropy of the dispersion. Instead, it arises from the phase structure of the multicomponent scattering states. The two
spin projection sectors exhibit different scattering and barrier-propagation phases, which enter as interference terms when both channels appear as a coherent superposition. This interference term is identified as the cause of the broken mirror
symmetry. We therefore discover an analog of the Imbert-Fedorov effect, at the level of interface-induced phase differences between internal wave components. Our result demonstrates that asymmetric tunneling can already occur in transport experiments, even in an idealized, isotropic multiband system, and should therefore not be automatically attributed solely to explicit band anisotropy.
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All authors Otman Bouladiane, Ahmed Jellal, Hocine Bahlouli, A. Al Luhaibi, Michael Vogl
High Energy Physics (Theory)
On background fields and a cutoff in sigma models
N. V. Kharuk
In this paper, using the example of a two-dimensional nonlinear sigma model with the Heisenberg group, we compare two variants of
chiral field decomposition into a background part and a fluctuation. It is shown that only one of these methods is consistent with the construction of the generating functional by introducing a background field. Furthermore, we perform a one-loop renormalization of the
quantum action, calculate power-law singularities in the two-loop approximation, and consider transition to an extended classical action. Finally, we study the consistency of the cutoff with special functional relations within the framework of the background field method.
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Chemical Physics
Local and Charge-Transfer Excitation of Pentacene-Buckminsterfullerene complexes
Ala Aldin M.Hani M. Darghouth, Omar A.Shareef, Firas A. AL-Lolage et al. (+1 more)
The charge transfer state, the local excited state on pentacene, and the local excited state on buckminsterfullerene have been studied for four models of the pentacene-buckminsterfullerene organic
solar cell. These models have different interface configurations between the donor and the acceptor. The study has been done by using different functionals and time-dependent density functional theory-namely, the long range-separated hybrid with coulomb-attenuating method approach (CAM-B3LYP functional), the popular B3LYP (Becke, three-parameter, Lee- Yang-Parr) exchange-correlation functional, and the density functional tight binding (DFTB) method. The charge transfer state energy obtained by using CAM-B3LYP without optimally tuned range-separated hybrid parameters are very close to those obtained by using a many-body dispersion-corrected, optimally tuned range-separated hybrid functional (OPT-wB97XD). Both the B3LYP functional and the DFTB method fail to describe correctly the charge transfer energy for all models. Each of them is underestimating around 1 eV compared with range-separated hybrid functional.
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All authors Ala Aldin M.Hani M. Darghouth, Omar A.Shareef, Firas A. AL-Lolage, Mark E. Casida
Quantum Physics
An Efficient and Perfect Secret Sharing Scheme on a Class of Non-Maximal Quantum Access Structure
Lei Li and Zhi Li
Quantum secret sharing is one of the core security technologies in the field of
quantum communication. Aiming at the problems of high
quantum resource consumption and the difficulty in balancing security and efficiency existing in current
quantum secret sharing schemes under non-maximal
quantum access structure(QAS), this paper focuses on the judgment criteria of non-maximal QAS and the construction methods of efficient and perfect
quantum secret sharing schemes on a kind of non-maximal QAS, i.e. hyperstar with three hyperedges. Firstly, we characterizes the forbidden sets and intermediate sets within this non-maximal QAS, and provides a characterization for non-maximal QAS realizable by pure-state encoding. Secondly, the representative element QAS of hyperstar with three hyperedges is defined, which serves as a substructure of this hyperstar QAS, and belongs to non-maximal QAS. Furthermore, we propose a universal, efficient, and perfect
quantum secret sharing scheme based on this hyperstar QAS using corresponding classical secret sharing scheme as an auxiliary. By deploying lightweight
quantum resources to representative element access structures, the proposed scheme reduces the difficulty in
quantum state preparation and distribution, and enhances its security and resource utilization efficiency.
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Mesoscale and Nanoscale Physics
Universality of dimensional crossovers in topological insulators
Lumen Eek, Zeb Osseweijer and Cristiane Morais Smith
We investigate dimensional crossovers in minimal tight-binding models of three-dimensional (3D) topological
insulators subject to
geometric confinement. While thin films are commonly understood to host a crossover from a 3D strong topological
insulator to a two-dimensional (2D)
quantum spin Hall phase via hybridization of surface states, we demonstrate that this picture is incomplete once bulk confinement effects and boundary termination are fully taken into account. Using
lattice models, we show that reducing the system size induces a strongly non-monotonic dependence of the
topology on thickness and microscopic parameters, leading to a sequence of topological phase transitions that is highly sensitive to surface termination. In particular, we find a cascade of dimensional reduction from a 3D topological
insulator to a 2D
quantum spin Hall phase and ultimately to a one-dimensional phase consisting of end states of Kramers pairs protected by inversion
symmetry. Remarkably, we show that both the 2D and 1D topological phases can emerge even when the corresponding 3D bulk phase is topologically trivial. Our results reveal an unexpected universality in the phase diagrams of 3D-to-2D and 2D-to-1D crossovers, pointing toward a unified framework for
topology under dimensional reduction.
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