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Physics

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Friday 9 October

Mesoscale and Nanoscale Physics

Establishing the role of thickness in LaOBr; an alternative gate dielectric for vdW heterostructures

Isaac Antoine Lagaud, Justin Boddison-Chouinard, Antoine Labbé et al. (+9 more)

In electronic devices, the quality of the dielectric material is determined by figures of merit such as the band gap, leakage onset field, breakdown field and the number of built-in defects, which can all limit device performance. An additional and important metric to consider is the strength of the dielectric constant. Hexagonal boron nitride (hBN) is the benchmark gate dielectric for two-dimensional van der Waals heterostructures, owing to its wide bandgap, and atomically flat interface. At the same time, its dielectric constant (2–4) highlights the opportunity to explore alternative higher-permittivity van der Waals dielectrics that provide stronger electrostatic control. Previous work established lanthanum oxybromide (LaOBr), a layered dielectric with a predicted dielectric constant of 12.5, as a potential dielectric for van der Waals heterostructures. Using graphene field-effect devices with LaOBr, we show that the leakage-onset and breakdown fields decrease systematically with thickness. Dual-gate capacitance measurements combined with a dead-layer model reveal a bulk dielectric constant of $\varepsilon_{\mathrm{bulk}} = 12.2$, in agreement with theory, while interfacial dead-layers cause the effective dielectric constant to vary from 6 to 11 across multiple thicknesses. Benchmarked against established gate dielectrics, LaOBr combines breakdown fields comparable to hBN with dielectric constants 2 to 3 times larger. By establishing the operating regime of devices with various thicknesses, we further confirm the advantage of LaOBr over hBN for high-capacitance gate-dielectric operation. These results validate LaOBr as a promising dielectric for integration into two-dimensional heterostructures, and establish thickness-dependent benchmarking as essential for evaluating emerging layered dielectric materials.
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All authors Isaac Antoine Lagaud, Justin Boddison-Chouinard, Antoine Labbé, Ayse Melis Aygar, Alex Bogan, Li-Lin Tay, Takashi Taniguchi, Kenji Watanabe, Aljoscha Söll, Zdeněk Sofer, Adina Luican-Mayer, Louis Gaudreau

Materials Science

Mn–Cr dopant association in dilute co-doped $\mathrm{ZnAl_2O_4}$ revealed by combined EPR and optical spectroscopy

Apoko S. Omondi, Mátyás M. Rudolf, Nikoletta Jegenyés et al. (+5 more)

Efficient and durable phosphors made from abundant elements underpin energy-saving solid-state lighting, near-infrared light sources for sensing, and X-ray and biomedical imaging. Co-doping is a standard route to brighter phosphors, yet the fate of the co-dopants is rarely established. We combine quantitative electron paramagnetic resonance (EPR) spin counting with photoluminescence, photoluminescence excitation, and X-ray-excited spectroscopy across two dilute Mn/Cr co-doping series of hydrothermally grown $\mathrm{ZnAl_2O_4}$ nanoparticles and show that the two ions can form an exchange-coupled, edge-sharing Cr–Mn defect complex, with $\mathrm{Mn^{2+/4+}}$ entering an octahedral site next to $\mathrm{Cr^{3+}}$. The octahedral Mn lifts the inversion symmetry of the $\mathrm{Cr^{3+}}$ site and strengthens its parity-forbidden absorption, enhancing the $\mathrm{Cr^{3+}}$ emission without energy transfer. The population of the defect complex follows the law of mass action, and above a threshold Mn concentration, Mn re-partitions into EPR-silent octahedral configurations that quench both emissions. Concentration optima in co-doped phosphors can thus reflect defect speciation, not only energy-transfer efficiency, which opens a structural design handle for brighter emitters.
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All authors Apoko S. Omondi, Mátyás M. Rudolf, Nikoletta Jegenyés, Árpád Jakab, Gábor Bortel, Bence G. Márkus, Adam Gali, Dávid Beke

Quantum Physics

Quantum Signal Processing Phase Factorization via Logarithmic Derivatives

Christopher Peng

Quantum signal processing (QSP) requires the efficient computation of phase factors associated with a polynomial transformation. One existing stable factorization method avoids direct root finding but relies on Prony's method to recover a polynomial from weighted power sums of its roots (arXiv:2202.02671). We present a modification of this approach that eliminates Prony's method by using the logarithmic derivative of an associated polynomial. Because the logarithmic derivative has the same residue at every root after accounting for multiplicity, its Fourier coefficients directly yield the unweighted power sums of the roots inside the unit disk. The Newton–Girard identities then recover the coefficients of the corresponding polynomial without computing its roots. The resulting algorithm has $O(d\log^2 d)$ computational complexity and simplifies the factorization procedure of the original method. In numerical experiments on Hamiltonian simulation, eigenstate filtering, matrix inversion, and the Fermi–Dirac operator, our implementation computes phase factors in seconds with maximum errors on the order of $10^{-12}$.
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Soft Condensed Matter

Explicit Solutions in a Probabilistic Cellular Automaton Model for Self-Assembled Monolayer Degradation

Wes Caldwell, Ryan Evans, Jacob Majikes et al. (+1 more)

Self-assembled monolayers (SAMs), formed by the adsorption of a monomolecular layer of adsorbate onto a surface, have emerged as leading candidates for plat- forms for electrochemical biosensors. In order to characterize the working age of a SAM-based biosensor, it is necessary to understand the long-term degradation of the monolayer, with particular emphasis on the intermolecular forces present in the self-assembly process. In this work, discrete- and continuous-time proba- bilistic cellular automaton (PCA) models for the degradation of SAMs involving adsorbate-adsorbate interactions are proposed in which adsorbate molecules desorb at a rate dependent only on the number of adsorbed neighbors. Impor- tantly, we make no assumptions on the relationship between degradation rate and adsorbed neighbors. Using techniques from generating function theory and complex analysis, the expected degradation curve is solved for explicitly in one dimension and shown to be a sigmoid curve related to the Gompertz function.
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All authors Wes Caldwell, Ryan Evans, Jacob Majikes, Anthony Kearsley

Soft Condensed Matter

Partitioning the magnetization raises the stability limit of ferromagnetic colloids

Paramita Modak, Priyadharshini M, Ankur Jaiswar et al. (+1 more)

Magnetic actuation scales with a particle's magnetic moment, yet practical colloidal suspensions remain superparamagnetic or weakly magnetized, a permanent dipole drives a near contact attraction growing as the square of the moment, binding particles irreversibly. Here we show that this constraint depends not only on how much magnetic material a particle carries, but on where it sits. Partitioning a fixed moment M into N internal elements leaves the far field interaction, and every actuation force, unchanged while suppressing the near-field pair energy by 1/N. As we show in our experiments across 57 samples and three geometries, stability collapses onto a single $\sim M^{2}/N$ boundary, raising the accessible dipolar energy scale nearly 150-fold. A liquid-phase analogue of magnetic force microscopy images the engineered energy landscape directly. The resulting colloids outrun size-matched superparamagnetic beads in weak fields far from a magnetic source, suggesting their applicability in hard to reach places. Together, these results open a new operating regime for colloidal manipulation, with impactful implications in microfluidics and drug delivery.
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All authors Paramita Modak, Priyadharshini M, Ankur Jaiswar, Ambarish Ghosh

Lattice Field Theory

Perturbative Renormalization of Noether Currents in SYM with Improved Discretizations

Marios Costa, Elias Antoniou, Salomi Dimou et al. (+4 more)

We investigate the perturbative renormalization of Noether currents associated with chiral symmetry and supersymmetry transformations in $\mathcal{N}=1$ supersymmetric Yang-Mills theory, regularized on the lattice using improved discretizations. In particular, we study the chiral current and the supercurrent operator for a broad class of lattice actions: Wilson fermions with one-step stout-smeared links and a clover term, together with a family of Symanzik-improved gluon actions. Since the supercurrent mixes with both gauge-invariant and gauge-noninvariant operators, we compute the corresponding renormalization factors and mixing coefficients at one-loop order. We analyze the impact of improved gluon and gluino actions on this mixing pattern and investigate whether suitable choices of lattice parameters, such as the clover and stout coefficients, can reduce unwanted lattice artifacts at one loop. Our results provide perturbative input for the implementation of Ward identities and for matching lattice observables to their continuum counterparts, while also offering guidance for simulations aimed at restoring supersymmetry in the continuum limit.
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All authors Marios Costa, Elias Antoniou, Salomi Dimou, Constantinos Costa, Panos K. Chrysanthis, Gregoris Spanoudes, Haralambos Panagopoulos

Mathematical Physics

An Introduction to the $p$-Differential Forms in Spinor Variables on the Minkowskian Manifold

Julio César Jaramillo Quiceno

This article presents an introductory study of $p$-differential forms in spinor variables defined on the Minkowskian (or Lorentzian) manifold. Starting from the algebraic and geometric foundations of spinor spaces and Clifford algebras, we establish the correspondence between Minkowski spacetime and Hermitian matrices in spinor coordinates. Within this framework, we construct differential 1-forms and 2-forms expressed in spinor notation, and formulate the Dirac operator in terms of exterior calculus. Furthermore, we extend this approach to the case of non-monogenic functions, following the method proposed in~\cite{Jaramillo2024}. The results illustrate the consistency of the spinorial exterior calculus and its potential applications in the study of relativistic field equations and geometric formulations of quantum theory.
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Materials Science

Benchmarking machine-learning interatomic potentials using classical force fields

Johannes Sandberg, Geneviève Dusson and Julien Lam

We propose a rational comparison between several well-known machine-learning interatomic potentials (linear atomic cluster expansion, the Behler-Parrinello high-dimensional neural network potential, and the graph neural network-based MACE potential) by testing their performance for fitting classical potentials such as the Lennard-Jones and Stillinger-Weber potential. With this we assess their advantages and limitations regarding several aspects: varying training dataset size, robustness to noise, carbon footprint, as well as the ability to reproduce the radial distribution function as an example observable. Overall the MACE models are shown to most accurately reproduce the potential energy surface, with little sign of overfitting, but at a significant computational cost, highlighting important questions regarding the choice of models in computational materials science.
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Chemical Physics

UGME: A python package for non-Markovian protein folding dynamics

Anthony J. Dominic III, Bertram Cham and Andrés Montoya-Castillo

Biomolecular processes, including protein folding, protein-protein association, and protein-DNA recognition, often occur on timescales beyond what individual atomistic molecular dynamics (MD) simulations can reach. To access these longer-timescale dynamics, practitioners commonly combine many parallelized, short trajectories into reduced kinetic models, such as Markov state models (MSMs), that describe how the biomolecules interconvert between a handful of biomolecular configurations (e.g., folded and unfolded states of a protein). Central to MSM construction is the assumption that, at sufficiently long time lags, these projected dynamics become memoryless, such that the future evolution of the system depends only on its current state. Yet, projecting high-dimensional biomolecular dynamics onto a small set of states necessarily discards information about unresolved degrees of freedom, including solvent reorganization, side-chain rearrangements, and intermediate configurations. Because these unresolved motions can continue to influence subsequent dynamics, the resulting dynamics retain memory that is absent from a Markovian description. Here, we present ugme, a modular, open-source Python package for constructing and validating generalized master equations (GME) models that explicitly account for these non-Markovian (memory) effects.
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Materials Science

Emergence of quantum transport in SnTe films upon structural refinement

Shrinkhala Sharma, Rabindra Basnet, Thomas Parker et al. (+4 more)

Topological crystalline insulators are distinguished from the conventional Z2 topological insulators by crystalline symmetry protection of the surface states. Quantitative characterization of these states requires magneto-transport measurements from which the phase coherence length and number of independent coherent channels can be extracted. Here we report such measurements on textured thin films of SnTe grown on Bi2Te3 buffered c-plane sapphire (Al2O3) by pulsed laser ablation. A post deposition annealing protocol was implemented to control the crystallographic texture, which reveals improved crystallinity and enhanced epitaxial alignment along the [111] direction in films annealed at elevated temperatures. The higher carrier density and lower resistivity seen in films annealed at 100 oC are suggestive of Sn vacancies which act as native acceptor defects, while films annealed at 200 oC approach the 1:1 stoichiometry. The magnetoresistance of all samples at T < 10 K characterized by a cusp centered around zero-field is suggestive of weak antilocalization and interpreted in the framework of the Hikami-Larkin-Nagaoka theory in the strong spin-orbit coupling limit. At T > 20 K, the MR is small and positive, and deviates from conventional Kohler scaling. An approximate collapse of the MR curves between 50 and 250 K is obtained using an empirical temperature-dependent scaling factor, indicating that changes in the Hall-derived carrier density alone cannot account for the observed scaling behavior. These results demonstrate that post growth annealing strongly influences the interplay between stoichiometry, crystallinity, and coherent transport in SnTe thin films.
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All authors Shrinkhala Sharma, Rabindra Basnet, Thomas Parker, Afolabi Akinfaderin, Alexander Samokhvalov, Rajeswari Kolagani, Ramesh C. Budhani

Medical Physics

Separating active irradiation from passive outcome learning in radiotherapy: a finite-model computational benchmark

Yuntao Wang

Apparent gains from informative irradiation may reflect treatment reoptimization or better use of outcomes from static treatment. We tested whether changing irradiation adds value beyond optimized static treatment, passive outcome learning, and data-dependent stopping. Three synthetic three-dimensional geometries supplied 51 parent fluences. Four known response scenarios generated Bernoulli risks from normalized organ-dose contrasts at uncalibrated slopes of 0, 4, 16, and 64; one unknown scenario applied to all 2,816 hypothetical uses. Loss included acquisition and deployment. We compared fixed passive and locally selected fixed active sampling, passive optimal stopping, and a restricted one-checkpoint, one-switch active policy with a shared terminal menu. Fixed active sampling improved on fixed passive sampling in three of nine nonzero-slope conditions, but never on passive stopping. One-switch adaptation added at most 4.00625e-5 expected model events avoided. With the policies held fixed, two of four increments above the numerical reporting threshold reversed sign under alternative integration; all four became negative at some allowed prior weighting. Adding three generated probes changed none of 72 paired policy values, and none was used on a positive-probability path. The tested probes did not demonstrate stable incremental value beyond optimized passive stopping. Treatment opportunities, stopping permissions, acquisition costs, and input sensitivity must be separated when attributing benefits to active irradiation. These are restricted finite-model results, not evidence about unrestricted active learning or clinical safety and effectiveness.
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High Energy Physics (Experiment)

Energy-energy correlators within $Z$-tagged jets in proton-proton collisions at $\sqrt{s}$ = 13 TeV

LHCb collaboration: R. Aaij, M. Abdelfatah, A.S.W. Abdelmotteleb et al. (+1187 more)

Energy-energy correlators probe perturbative and nonperturbative QCD regimes of jet formation through momentum-weighted angular correlations between hadrons. First measurements in light-quark-enriched jets are presented for inclusive, like-sign, and opposite-sign charged-hadron pairs, using proton-proton collisions at LHCb. The results support universality of the confinement scale for light-quark-initiated jets across collision systems and the reported transverse momentum scale of the jet. In the charge-dependent measurements, opposite-sign correlations are enhanced as angular separation decreases down to the confinement-scale region, a behavior that is well described by simulations.
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All authors LHCb collaboration: R. Aaij, M. Abdelfatah, A.S.W. Abdelmotteleb, C. Abellan Beteta, F. Abudinén, T. Ackernley, A.A. Adefisoye, B. Adeva, M. Adinolfi, P. Adlarson, C. Agapopoulou, C.A. Aidala, S. Akar, K. Akiba, H. Al Saleh, P. Albicocco, J. Albrecht, R. Aleksiejunas, F. Alessio, P. Alvarez Cartelle, A.A. Alves Jr, S. Amato, J.L. Amey, Y. Amhis, Z. Amos, L. An, L. Anderlini, P. Andreola, M. Andreotti, S. Andres Estrada, A. Anelli, D. Ao, C. Arata, F. Archilli, Z. Areg, M. Argenton, S. Arguedas Cuendis, L. Arnone, M. Artuso, E. Aslanides, R. Ataíde Da Silva, M. Atzeni, B. Audurier, J.A. Authier, D. Bacher, I. Bachiller Perea, S. Bachmann, M. Bachmayer, J.J. Back, M. Bai, Z.B. Bai, V. Balagura, A. Balboni, W. Baldini, Z. Baldwin, L. Balzani, H. Bao, J. Baptista de Souza Leite, C. Barbero Pretel, M. Barbetti, I.R. Barbosa, W. Barker, R.J. Barlow, M. Barnyakov, S. Baron, S. Barsuk, W. Barter, J. Bartz, S. Bashir, B. Batsukh, P.B. Battista, A. Bavarchee, A. Bay, A. Beck, M. Becker, F. Bedeschi, I.B. Bediaga, N.A. Behling, S. Belin, A. Bellavista, I. Belyaev, G. Bencivenni, E. Ben-Haim, J.L.M. Berkey, R. Bernet, A. Bertolin, L. Bertsch, F. Betti, J. Bex, O. Bezshyyko, S. Bhattacharya, M.S. Bieker, N.V. Biesuz, A. Biolchini, M. Birch, F.C.R. Bishop, A. Bitadze, A. Bizzeti, T. Blake, F. Blanc, J.E. Blank, S. Blusk, J.A. Boelhauve, O. Boente Garcia, T. Boettcher, A. Bohare, C. Bolognani, R.B. Bonacci, A. Bordelius, F. Borgato, S. Borghi, M. Borsato, J.T. Borsuk, E. Bottalico, S.A. Bouchiba, M. Bovill, T.J.V. Bowcock, A. Boyer, C. Bozzi, J.D. Brandenburg, A. Brea Rodriguez, N. Breer, C. Breitfeld, J. Brodzicka, J. Brown, E. Buchanan, M. Burgos Marcos, C. Burr, E. Butera, C. Buti, J.S. Butter, W. Byczynski, S. Cadeddu, H. Cai, Y. Cai, Y. Cai, A. Caillet, R. Calabrese, L. Calefice, M. Calvi, M. Calvo Gomez, P. Camargo Magalhaes, J.I. Cambon Bouzas, P. Campana, A. Campomagnani, A.C. Campos, A.F. Campoverde Quezada, Y. Cao, S. Capelli, M. Caporale, L. Capriotti, R. Caravaca-Mora, A. Carbone, L. Carcedo Salgado, R. Cardinale, A. Cardini, P. Carniti, L. Carus, R. Caspary, G. Casse, M. Cattaneo, G. Cavallero, V. Cavallini, S. Celani, I. Celestino, S. Cesare, A.J. Chadwick, M. Charles, Ph. Charpentier, E. Chatzianagnostou, R. Cheaib, M. Chefdeville, C. Chen, J. Chen, S. Chen, Z. Chen, A. Chen Hu, M. Cherif, S. Chernyshenko, X. Chiotopoulos, G. Chizhik, V. Chobanova, A. Christakakis, M. Chrzaszcz, Y. Chu, V. Chulikov, P. Ciambrone, X. Cid Vidal, P. Cifra, P.E.L. Clarke, M. Clemencic, H.V. Cliff, J. Closier, C. Cocha Toapaxi, V. Coco, A. Codovini, C.S. Codovini, J. Cogan, E. Cogneras, L. Cojocariu, S. Collaviti, P. Collins, T. Colombo, M. Colonna, A. Comerma-Montells, L. Congedo, J. Connaughton, A. Contu, N. Cooke, A. Corallo, G. Cordova, C. Coronel, I. Corredoira, A. Correia, G. Corti, G.C. Costantino, C. Cotirlan, J. Cottee Meldrum, B. Couturier, D.C. Craik, N. Crepet, M. Cruz Torres, M. Cubero Campos, E. Curras Rivera, R. Currie, C.L. Da Silva, X. Dai, J. Dalseno, C. D'Ambrosio, G. Darze, A. Davidson, O. De Aguiar Francisco, C. De Angelis, F. De Benedetti, J. de Boer, K. De Bruyn, S. De Capua, M. De Cian, U. De Freitas Carneiro Da Graca, F. De Gregorio, E. De Lucia, J.M. De Miranda, L. De Paula, A. De Robertis, E. De Santis, M. De Serio, P. De Simone, F. De Vellis, J.A. de Vries, F. Debernardis, D. Decamp, S. Dekkers, L. Del Buono, B. Delaney, B. Demaire-Lepape, J. Deng, O. Deschamps, F. Dettori, B. Dey, P. Di Nezza, S. Ding, Y. Ding, L. Dittmann, J.F. Diverchy, A.D. Docheva, A. Doheny, C. Dong, F. Dordei, J. Dorta Moreno, A.C. dos Reis, J. Dos Santos Oliveira, A.D. Dowling, L. Dreyfus, W. Duan, P. Duda, L. Dufour, V. Duk, P. Durante, M.M. Duras, J.M. Durham, K. Duwe, A. Dziurda, S. Easo, E. Eckstein, U. Egede, S. Eisenhardt, E. Ejopu, L. Eklund, M. Elashri, D. Elizondo Blanco, J. Ellbracht, S. Ely, A. Ene, T. Evans, F. Fabiano, S. Faghih, L.N. Falcao, B. Fang, R. Fantechi, L. Fantini, M. Faria, K. Farmer, F. Fassin, D. Fazzini, L. Felkowski, C. Feng, M. Feng, A. Fernandez Casani, M. Fernandez Gomez, B. Fernandez Rodino, J. Fernandez-John, A.D. Fernez, F. Ferrari, F. Ferreira Rodrigues, R.A. Fini, R. Fiorenza, M. Fiorini, M. Firlej, D.S. Fitzgerald, C. Fitzpatrick, T. Fiutowski, F. Fleuret, A. Fomin, M. Fontana, M. Fontes Vaz, L.A. Foreman, R. Forty, D. Foulds-Holt, V. Franco Lima, M. Franco Sevilla, M. Frank, E. Franzoso, G. Frau, C. Frei, D.A. Friday, J. Fu, Y. Fu, Q. Führing, T. Fulghesu, G. Galati, M.D. Galati, A. Gallas Torreira, D. Galli, S. Gambetta, M. Gandelman, P. Gandini, B. Ganie, H. Gao, R. Gao, T.Q. Gao, Y. Gao, Y. Gao, Y. Gao, L.M. Garcia Martin, P. Garcia Moreno, J. García Pardiñas, P. Gardner, L. Garrido, C. Gaspar, A. Gavrikov, J. George, E. Gersabeck, M. Gersabeck, T. Gershon, S. Ghizzo, Z. Ghorbanimoghaddam, F.I. Giasemis, V. Gibson, H.K. Giemza, A.L. Gilman, M. Giovannetti, A. Gioventù, L. Girardey, M.A. Giza, F.C. Glaser, V.V. Gligorov, C. Göbel, L. Golinka-Bezshyyko, E. Golobardes, A. Golutvin, S. Gomez Fernandez, A.G. Gomez Mongui, W. Gomulka, F. Goncalves Abrantes, I. Gonçales Vaz, M. Goncerz, G. Gong, S. Gong, J.A. Gooding, C. Gotti, E. Govorkova, J.P. Grabowski, L.A. Granado Cardoso, R. Grande Quartieri, E. Graugés, E. Graverini, L. Grazette, G. Graziani, A.T. Grecu, N.A. Grieser, L. Grillo, C. Gu, M. Guarise, L. Guerry, A.-K. Guseinov, Y. Guz, T. Gys, K. Habermann, T. Hadavizadeh, C. Hadjivasiliou, G. Haefeli, C. Haen, S. Haken, G. Hallett, P.M. Hamilton, Q. Han, S. Han, X. Han, S. Hansmann-Menzemer, N. Harnew, T.J. Harris, L. Hartman, M. Hartmann, S. Hashmi, J. He, N. Heatley, A. Hedes, F. Hemmer, C. Henderson, R. Henderson, R.D.L. Henderson, A.M. Hennequin, K. Hennessy, A. Henrot, J. Herd, P. Herrero Gascon, J. Heuel, A. Heyn, A. Hicheur, G. Hijano Mendizabal, J. Horswill, R. Hou, Y. Hou, D.C. Houston, N. Howarth, W. Hu, X. Hu, W. Hulsbergen, R.J. Hunter, D. Hutchcroft, M. Idzik, P. Ilten, A. Iohner, S. Jacevicius, H. Jage, S.J. Jaimes Elles, S. Jakobsen, T. Jakoubek, E. Jans, A. Jawahery, C. Jayaweera, A. Jelavic, V. Jevtic, Z. Jia, E. Jiang, X. Jiang, Y. Jiang, Y.J. Jiang, E. Jimenez Moya, N. Jindal, M. John, A. John Rubesh Rajan, D. Johnson, C.R. Jones, S. Joshi, B. Jost, J. Juan Castella, N. Jurik, I. Juszczak, K. Kalecinska, D. Kaminaris, S. Kandybei, M. Kane, Y. Kang, C. Kar, A. Kauniskangas, J.W. Kautz, M.K. Kazanecki, F. Keizer, M. Kenzie, T. Ketel, B. Khanji, S. Kholodenko, V. Kholoimov, G. Khreich, F. Kiraz, T. Kirn, V.S. Kirsebom, N. Kleijne, A. Kleimenova, D. Klekots, K. Klimaszewski, M.R. Kmiec, T. Knospe, R. Kolb, S. Koliiev, L. Kolk, A. Konoplyannikov, P. Kooij, P. Kopciewicz, P. Koppenburg, A. Korchin, I. Kostiuk, O. Kot, S. Kotriakhova, E. Kowalczyk, O. Kravcov, M. Kreps, W. Krupa, W. Krzemien, O. Kshyvanskyi, S. Kubis, M. Kucharczyk, A. Kupsc, A. Kurzina, V. Kushnir, B. Kutsenko, J. Kvapil, I. Kyryllin, D. Lacarrere, P. Laguarta Gonzalez, A. Lai, A. Lampis, D. Lancierini, C. Landesa Gomez, G. Lanfranchi, C. Langenbruch, T. Latham, F. Lazzari, C. Lazzeroni, R. Le Gac, H. Lee, R. Lefèvre, M. Lehuraux, C. Lemettais, E. Lemos Cid, O. Leroy, T. Lesiak, E.D. Lesser, B. Leverington, A. Li, C. Li, C. Li, H. Li, J. Li, K. Li, L. Li, L. Li, P. Li, P.-R. Li, Q. Li, T. Li, T. Li, W. Li, Y. Li, Y. Li, Y. Li, Z. Li, Z. Lian, Q. Liang, X. Liang, Z. Liang, S. Libralon, A. Lightbody, J. Lin, S. Lin, T. Lin, R. Lindner, H. Linton, R. Litvinov, D. Liu, F.L. Liu, G. Liu, K. Liu, S. Liu, W. Liu, X. Liu, Y. Liu, Y. Liu, Y.L. Liu, G. Loachamin Ordonez, I. Lobo, A. Lobo Salvia, A. Loi, T. Long, F.C.L. Lopes, J.H. Lopes, A. Lopez Huertas, C. Lopez Iribarnegaray, Q. Lu, C. Lucarelli, D. Lucchesi, M. Lucio Martinez, Y. Luo, A. Lupato, M. Lupberger, E. Luppi, K. Lynch, J. Lyu, S. Lyu, X.-R. Lyu, H. Ma, S. Maccolini, F. Machefert, F. Maciuc, B. Mack, I. Mackay, L.M. Mackey, L.R. Madhan Mohan, M.J. Madurai, D. Magdalinski, J.J. Malczewski, S. Malde, L. Malentacca, G. Manca, C. Mancuso, R. Manera Escalero, A. Mangalasseri, F.M. Manganella, R. Mangrulkar, D. Manuzzi, S. Mao, D. Marangotto, J.F. Marchand, R. Marchevski, U. Marconi, L. Mareso, E. Mariani, S. Mariani, C. Marin Benito, J. Marks, A.M. Marshall, L. Martel, G. Martelli, G. Martellotti, L. Martinazzoli, M. Martinelli, C. Martinez, A. Martinez Armas, D. Martinez Gomez, D. Martinez Santos, F. Martinez Vidal, A. Martorell i Granollers, A. Massafferri, R. Matev, A. Mathad, C. Matteuzzi, K.R. Mattioli, L. Matzner, A. Mauri, E. Maurice, J. Mauricio, P. Mayencourt, J. Mazorra de Cos, M. Mazurek, D. Mazzanti Tarancon, M. McCann, N.T. McHugh, A. McNab, R. McNulty, B. Meadows, S.E.R. Medaer, D. Melnychuk, D. Mendoza Granada, P. Menendez Valdes Perez, F.M. Meng, M. Merk, A. Merli, L. Meyer Garcia, D. Miao, H. Miao, S. Mico, M. Mikhasenko, D.A. Milanes, A. Minotti, E. Minucci, B. Mitreska, D.S. Mitzel, R. Mocanu, A. Modak, L. Moeser, R.D. Moise, E.F. Molina Cardenas, T. Mombächer, M. Monk, T. Monnard, S. Monteil, A. Morcillo Gomez, G. Morello, M.J. Morello, M.P. Morgenthaler, A. Moro, J. Moron, W. Morren, A.B. Morris, A.G. Morris, R. Mountain, Z. Mu, N. Muangkod, E. Muhammad, F. Muheim, M. Mulder, K. Müller, F. Muñoz-Rojas, V. Mytrochenko, P. Naik, T. Nakada, R. Nandakumar, G. Napoletano, I. Nasteva, M. Needham, N. Neri, S. Neubert, N. Neufeld, J. Nicolini, D. Nicotra, E.M. Niel, L. Nisi, Q. Niu, B.K. Njoki, P. Nogarolli, P. Nogga, J. Nombela Royo, C. Normand, A. Novo Cal, J. Novoa Fernandez, G. Nowak, H.N. Nur, A. Oblakowska-Mucha, T. Oeser, O. Okhrimenko, R. Oldeman, N. Oldman, F. Oliva, E. Olivart Pino, M. Olocco, R.H. O'Neil, J.S. Ordonez Soto, D. Osthues, J.M. Otalora Goicochea, A. Oyanguren, O. Ozcelik, F. Paciolla, A. Padee, K.O. Padeken, B. Pagare, T. Pajero, A. Palano, L. Palini, L. Palombini, M. Palutan, C. Pan, X. Pan, S. Panebianco, S. Paniskaki, L. Paolucci, A. Papanestis, M. Pappagallo, L.L. Pappalardo, C. Pappenheimer, C. Parkes, D. Parmar, G. Passaleva, D. Passaro, A. Pastore, M. Patel, J. Patoc, C. Patrignani, A. Paul, C.J. Pawley, A. Pellegrino, J. Peng, X. Peng, M. Pepe Altarelli, S. Perazzini, H. Pereira Da Costa, M. Pereira Martinez, A. Pereiro Castro, C. Perez, A. Perez Casas, P. Perret, A. Perrevoort, A. Perro, M.J. Peters, A. Petkovic, K. Petridis, A. Petrolini, S. Pezzulo, J.P. Pfaller, H. Pham, L. Pica, E. Picatoste Olloqui, M. Piccini, L. Piccolo, F. Piernas Diaz, B. Pietrzyk, R.N. Pilato, D. Pinci, F. Pisani, M. Pizzichemi, V.M. Placinta, M. Plo Casasus, T. Poeschl, F. Polci, M. Poli Lener, A. Poluektov, I. Polyakov, E. Polycarpo, S. Ponce, D. Popov, K. Popp, K. Prasanth, C. Prouve, D. Provenzano, V. Pugatch, A. Puicercus Gomez, G. Punzi, J.R. Pybus, Q. Qian, W. Qian, N. Qin, R. Quagliani, R.I. Rabadan Trejo, B. Rachwal, R. Racz, J.H. Rademacker, M. Rama, M. Ramírez García, V. Ramos De Oliveira, M. Ramos Pernas, G. Ramsey, M.S. Rangel, G. Raven, M. Rebollo De Miguel, F. Redi, J. Reich, F. Reiss, Z. Ren, P.K. Resmi, M. Ribalda Galvez, R. Ribatti, G. Ricart, D. Riccardi, S. Ricciardi, K. Richardson, M. Richardson-Slipper, F. Riehn, K. Rinnert, P. Robbe, G. Robertson, E. Rodrigues, A. Rodriguez Alvarez, E. Rodriguez Fernandez, J.A. Rodriguez Lopez, E. Rodriguez Rodriguez, J. Roensch, A. Rogovskiy, D.L. Rolf, P. Roloff, A. Romano, V. Romanovskiy, A. Romero Vidal, G. Romolini, F. Ronchetti, T. Rong, W. Rose, M. Rotondo, M.S. Rudolph, G. Ruggiero, M. Ruiz Diaz, J. Ruiz Vidal, J. Ruz Armendariz, J.J. Saavedra-Arias, J.J. Saborido Silva, D. Sahoo, N. Sahoo, B. Saitta, M. Salomoni, I. Sanderswood, R. Santacesaria, C. Santamarina Rios, M. Santimaria, L. Santoro, E. Santovetti, A. Saputi, A. Sarnatskiy, G. Sarpis, M. Sarpis, C. Satriano, A. Satta, M. Saur, H. Sazak, F. Sborzacchi, A. Scarabotto, S. Schael, S. Scherl, M. Schiller, H. Schindler, M. Schmelling, B. Schmidt, N. Schmidt, S. Schmitt, H. Schmitz, O. Schneider, A. Schopper, N. Schulte, H. Schumacher, M.H. Schune, G. Schwering, B. Sciascia, A. Sciuccati, G. Scriven, I. Segal, S. Sellam, M. Senghi Soares, A. Sergi, N. Serra, L. Sestini, B. Sevilla Sanjuan, Y. Shang, D.M. Shangase, R.S. Sharma, L. Shchutska, T. Shears, S. Shelton, J. Shen, Z. Shen, S. Sheng, B. Shi, J. Shi, Q. Shi, W.S. Shi, E. Shmanin, R. Silva Coutinho, G. Simi, S. Simone, M. Singha, I. Siral, N. Skidmore, T. Skwarnicki, M.W. Slater, E. Smith, M. Smith, L. Soares Lavra, M.D. Sokoloff, F.J.P. Soler, A. Solomin, K. Solovieva, N.S. Sommerfeld, R. Song, Y. Song, Y. Song, Y.S. Song, F.L. Souza De Almeida, G. Souza De Castro, B. Souza De Paula, K.M. Sowa, E. Spadaro Norella, E. Spedicato, J.G. Speer, P. Spradlin, F. Stagni, M. Stahl, S. Stahl, S. Stanislaus, M. Stefaniak, O. Steinkamp, F. Suljik, J. Sun, L. Sun, M. Sun, D. Sundfeld, P. Svihra, V. Svintozelskyi, J. Swallow, K. Swientek, F. Swystun, A. Szabelski, T. Szumlak, Y. Tan, Y. Tang, Y.T. Tang, M.D. Tat, J.A. Teijeiro Jimenez, F. Terzuoli, F. Teubert, E. Thomas, D.J.D. Thompson, A.R. Thomson-Strong, R. Thornton, H. Tilquin, V. Tisserand, S. T'Jampens, M. Tobin, T.T. Todorov, L. Tomassetti, G. Tonani, X. Tong, T. Tork, L. Torlai, L. Toscano, D.Y. Tou, G. Tuci, N. Tuning, L.H. Uecker, A. Ukleja, A. Upadhyay, B. Urbach, A. Usachov, U. Uwer, V. Vagnoni, A. Vaitkevicius, A. Valassi, V. Valcarce Cadenas, G. Valenti, N. Valls Canudas, J. van Eldik, H. Van Hecke, E. van Herwijnen, C.B. Van Hulse, R. Van Laak, M. van Veghel, P. Varrella, R. Vazquez Gomez, P. Vazquez Regueiro, C. Vázquez Sierra, S. Vecchi, J. Velilla Serna, J.J. Velthuis, M. Veltri, A. Venkateswaran, M. Verdoglia, M. Vesterinen, W. Vetens, D. Vico Benet, P. Vidrier Villalba, M. Vieites Diaz, X. Vilasis-Cardona, E. Vilella Figueras, A. Villa, P. Vincent, B. Vivacqua, F.C. Volle, D. vom Bruch, K. Vos, C. Vrahas, J. Wagner, J. Walsh, N. Walter, E.J. Walton, G. Wan, A. Wang, B. Wang, C. Wang, C. Wang, C. Wang, G. Wang, H. Wang, J. Wang, J. Wang, J. Wang, J. Wang, M. Wang, N.W. Wang, X. Wang, X. Wang, X. Wang, X.W. Wang, Y. Wang, Y. Wang, Y. Wang, Y.H. Wang, Z. Wang, Z. Wang, J.A. Ward, M. Waterlaat, N.K. Watson, D. Websdale, Y. Wei, Z. Weida, J. Wendel, B.D.C. Westhenry, A.S. White, C. White, M. Whitehead, E. Whiter, A.R. Wiederhold, D. Wiedner, M.A. Wiegertjes, C. Wild, G. Wilkinson, M.K. Wilkinson, M. Williams, M.J. Williams, M.R.J. Williams, R. Williams, S. Williams, Z. Williams, F.F. Wilson, M. Winn, W. Wislicki, M. Witek, L. Witola, T. Wolf, E. Wood, G. Wormser, S.A. Wotton, H. Wu, J. Wu, T. Wu, X. Wu, Y. Wu, Z. Wu, K. Wyllie, S. Xian, Z. Xiang, Y. Xie, T.X. Xing, A. Xu, L. Xu, M. Xu, R. Xu, Z. Xu, Z. Xu, Z. Xu, Z. Xu, S. Yadav, K. Yang, X. Yang, Y. Yang, Y. Yang, Z. Yang, Z. Yang, H. Yeung, H. Yin, X. Yin, C.Y. Yu, J. Yu, K. Yu, X. Yuan, Y Yuan, S. Zalambani, J.A. Zamora Saa, F. Zangari, M. Zavertyaev, M. Zdybal, F. Zenesini, C. Zeng, M. Zeng, S.H Zeng, C. Zhang, C. Zhang, D. Zhang, J. Zhang, L. Zhang, Q.Z. Zhang, R. Zhang, S. Zhang, S.L. Zhang, Y. Zhang, Z. Zhang, J. Zhao, M. Zhao, Y. Zhao, A. Zhelezov, S.Z. Zheng, X.Z. Zheng, Y. Zheng, T. Zhou, X. Zhou, V. Zhovkovska, L.Z. Zhu, X. Zhu, X. Zhu, Y. Zhu, V. Zhukov, J. Zhuo Gao, T. Zies, D. Zuliani, X. Zuo

Materials Science

Anisotropic pressure response of thermal conductivity in crystalline polytetrafluoroethylene

Maissa Adi, Jamal Abou Haibeh and Samuel Huberman

Compression can change thermal conductivity differently along polymer chains and across them by altering phonon velocities and lifetimes. We examine this directional response in orthorhombic Form III polytetrafluoroethylene (PTFE) at calculated pressures of 1.503, 3.452, and 5.056 GPa, using first-principles harmonic and cubic force constants within the single-mode relaxation-time approximation (SMRTA). At 100, 200, and 300 K, the chain-axis conductivity decreases at every pressure step. Between 3.452 and 5.056 GPa, both transverse components recover: at 300 K they increase by 23.7% and 13.7%, while the longitudinal conductivity decreases by 14.5%. An exact factorization separates the conductivity into a heat-capacity–velocity factor and a weighted effective lifetime. The transverse recovery follows from larger heat-capacity-weighted squared velocities, consistent with stiffer interchain restoring forces. Along the chains, shorter effective lifetimes dominate, and both conductivity-weighted Normal and Umklapp rates increase at 300 K. Comparing the same cubic force-constant blocks at all three pressures, we find that interchain coupling is already substantial at 1.503 GPa and increases under compression.
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High Energy Physics (Phenomenology)

Factorisation theorem and pole cancellation in the resolved $Q_1^q$-$Q_{7\gamma}$ contribution to $\bar{B}\to X_s\gamma$ at NLO

Riccardo Bartocci and Tobias Hurth

We study the subleading resolved $Q_1^q$-$Q_{7\gamma}$ contribution to the inclusive decay $\bar{B}\to X_s\gamma$ at next-to-leading order (NLO) in $\alpha_s$. We present a formulation of the factorisation theorem which is valid beyond the leading order (LO). On this basis, we explicitly demonstrate the cancellation of all $1/\varepsilon$ singularities between the hard, hard-collinear, anti-hard-collinear and soft contributions. For this purpose, a central result of this work is the computation of the $u$-integrated massless two-loop anti-hard-collinear jet function, which determines the structure of the $1/\varepsilon$ singularities. In addition, we compute the hard function at the required order, combine our results with the hard-collinear jet function known from the literature, and employ the shape function whose renormalisation was determined in our previous work. There, we showed, for inclusive as well as for exclusive modes, that certain contributions to these multi-light-cone soft functions are physically irrelevant and can be consistently omitted; the explicit cancellation of the corresponding divergences provides a non-trivial confirmation of this statement. Overall, our findings constitute a non-trivial consistency check of the factorisation framework for this subleading resolved contribution at NLO and provide the basis for a full phenomenological analysis.
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Quantum Physics

Below-threshold execution of fault-tolerant ripple-carry addition on a trapped-ion quantum computer

Jacob S. Nelson, Andrew J. Landahl and Andrew D. Baczewski

We deploy a universal fault-tolerant quantum computing (FTQC) architecture based on error-detecting $[\![8,3,2]\!]$ and $[\![4,2,2]\!]$ codes on Quantinuum's Helios-1 trapped-ion quantum computer. We compile and execute ripple-carry adder (RCA) circuits for classical inputs up to five bits on this architecture. Uncomputing a workspace qubit provides an additional “algorithmic check” to detect errors. While available at both the physical and logical levels, this check synergizes with our architecture by increasing the effective fault distance of many circuit locations from two to four. Combining this algorithmic check with the error-detecting codes, we observed only a single logical failure in one-bit addition after burst-error filtering, yielding an estimated logical failure rate of $(6.0 \pm 5.9) \times 10^{-5}$. This is well below the $(3.5 \pm 1.3) \times 10^{-3}$ failure probability observed for one-bit addition on the same hardware in unencoded form. Two- and three-bit adders also showed performance improvements, while the longer four- and five-bit adders executed just above threshold.
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Materials Science

Precursor stoichiometry controls dopant structure, defect chemistry, and valence in Mn-doped ZnGa$_2$O$_4$ nanocrystals

Mátyás M. Rudolf, Gábor Bortel, Nikoletta Jegenyés et al. (+5 more)

The luminescence of doped nanocrystals is usually optimised through the activator; here we show that the host cation ratio is an equally decisive, and largely overlooked, design variable. Mn-doped ZnGa$_2$O$_4$ nanocrystals (Mn:Zn = $4\times10^{-4}$) were grown hydrothermally at nominal Zn/Ga ratios between 0.30 and 0.75 (stoichiometric: 0.50) and post-annealed at 400–1100$^\circ$C, and the resulting composition–temperature matrix was mapped by X-ray- and UV-excited luminescence, EPR, Rietveld-refined X-ray diffraction, Raman spectroscopy and SEM. The as-grown crystals are phase-pure spinel at every composition and accommodate their off-stoichiometry internally as a point-defect inventory, reflected in a 0.4% variation of the lattice parameter; on annealing, the excess gallium is exsolved as $\beta$-Ga$_2$O$_3$ in amounts set by the solution composition. The Mn$^{2+}$ emission separates into two optima, near-stoichiometric crystals annealed at 400–600$^\circ$C and Zn-excess crystals annealed at 1100$^\circ$C, the latter being twice as bright under X-ray excitation. Under X-ray and 365~nm excitation the two optima are separated by a minimum at 800$^\circ$C that coincides with a collapse of the Mn$^{2+}$ EPR population and has no counterpart in the Raman linewidths, identifying transient, defect-compensated oxidation of the dopant rather than lattice degradation as its origin. The most Zn-rich composition shows neither Mn$^{2+}$ nor Mn$^{4+}$ emission at any annealing stage, whereas its trace Cr$^{3+}$ emission is strong, indicating that Mn is rejected already during growth. Solution stoichiometry therefore acts on two levels, dopant capture and native-defect inventory, while annealing controls dopant valence and lattice order. The brightest high-temperature phosphor is thus not the nominally stoichiometric one, but the composition whose excess is consumed on its way to stoichiometry.
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All authors Mátyás M. Rudolf, Gábor Bortel, Nikoletta Jegenyés, Árpád Jakab, László Bencs, Ferenc Simon, Adam Gali, Dávid Beke

Quantum Physics

Lifting an $[n,k,d]$ Binary Linear Code to an $[[n,k,d]]$ Quantum Stabilizer Code

Thamadathil Aswanth and Navin Kashyap

The codeword stabilized (CWS) framework provides a systematic method for constructing quantum error correcting codes from a simple undirected graph and a classical code. When the underlying classical code is linear, the resulting quantum code is a stabilizer code. In this work, we investigate the conditions under which an arbitrary $[n,k,d]$ classical binary linear code can be lifted to an $[[n,k,d]]$ quantum stabilizer code using the CWS framework. We analyze the random CWS code constructed from a given $[n,k,d]$ binary linear code $\mathcal{C}$ and an Erdős-Rényi random graph $\mathrm{G}(n, \frac12)$. We establish a lower bound on the probability that the resulting quantum code preserves the minimum distance $d$ of the classical code. This probabilistic analysis yields a Gilbert-Varshamov-type condition on the $n,k,d$ parameters of the classical code that guarantees the existence of a graph resulting in a quantum code with the same $n,k,d$ parameters.
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High Energy Physics (Theory) · Cross-listed from math.AG

Gauss-Manin Connection in Disguise: Holomorphic Anomaly Equations and Higher Genus Real Gromov-Witten Invariants

Felipe Espreafico

We construct an algebraic framework for the extended holomorphic anomaly equations following ideas of Alim, Movasati, Scheidegger and Yau. We choose the quintic threefold as our main model and use this framework to solve the equations and fix the ambiguity up to genus 5. We obtain predictions for real Gromov-Witten invariants, or, equivalently, real Gopakumar-Vafa invariants that are integers and agree with their complex counterparts modulo 2. In the end, we discuss how the framework could be extended and compute the same predictions for the bicubic up to genus 9.
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High Energy Physics (Phenomenology)

A Comprehensive Interpretation of the LZ High-Energy Recoil Event: A Minimal $U(1)_B$ Dark Sector and Its Experimental Tests

Mattia Di Mauro

The $248$ keV nuclear-recoil candidate reported by LUX-ZEPLIN (LZ) motivates an inelastic dark matter (DM) interpretation, in which scattering converts the DM particle into a slightly heavier state. We provide a comprehensive study of this interpretation in an anomaly-free model of gauged baryon number, where a new vector boson, $Z_B$, mediates interactions between DM and quarks. Breaking the baryonic gauge symmetry generates the new particle masses and a small splitting between two DM states, while a residual symmetry keeps the lighter state stable. We identify regions compatible with the LZ candidate, the observed DM abundance, and current ATLAS and CMS dijet constraints. Within the scanned domain, these regions span DM masses $m_\chi\simeq0.19$-$4.5$ TeV, mediator masses $M_{Z_B}\simeq0.05$-$5.0$ TeV, and gauge couplings $g_B\simeq0.004$-$0.74$, with correlated values of these parameters. A representative thermal solution has $m_\chi=1$ TeV, $M_{Z_B}=1.44$ TeV, $g_B\simeq0.228$, and a mass splitting of $300$ keV. A small electroweak mixing allows the heavier DM state to decay rapidly, suppressing unwanted signals from its surviving population. This interpretation can be tested through complementary measurements: additional LZ and XENONnT data can establish whether the high-energy recoil signal persists, ATLAS and CMS Run-3 dijet searches can probe the mediator mass and coupling, and a dedicated IceCube analysis of four-quark final states can test DM capture and annihilation in the Sun. Together, these measurements can test complementary parts of the surviving region and assess whether the LZ candidate is consistent with this interpretation.
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High Energy Astrophysical Phenomena

A Pipeline for the AI-Assisted Analysis of Imaging X-ray Polarimetry Explorer Observations of Black Hole X-ray Binaries and Limits on Their Polarization Variability

B. Domine, B. Liu, H. Krawczynski et al. (+3 more)

The Imaging X-ray Polarimetry Explorer (IXPE) has opened a new window into the high-energy Universe, with the capability to measure the arrival time, arrival direction, energy, and, for the first time with the required sensitivity, the polarization of X-rays from black holes, neutron stars, and other cosmic sources of X-rays. In this paper, we discuss the use of Artificial Intelligence (AI) agents for the analysis of IXPE data. The pipeline combines an immutable code base with evolving knowledge databases. The generation of analysis projects makes use of a literature data base to judge the novelty of the proposed analysis projects. We emphasize that the analysis requires two types of expert knowledge: detailed instructions about how to reduce the X-ray data, and expert knowledge about how to interpret the results. We employ several levels of auditors that scrutinize the analysis plan, the analysis scripts, and the analysis results for data and method adequacy. The pipeline includes a staggered approach to interpret the analysis results. We present exemplary results from the pipeline applied to IXPE observations of Black Hole X-ray Binaries (BHXRBs) including comparisons of results from the analysis pipeline with published results and a systematic search for polarization degree and polarization angle variability in long IXPE observations. We critically discuss the performance of the pipeline and future avenues for improving it.
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All authors B. Domine, B. Liu, H. Krawczynski, M. Kundu, Shravan Vengalil Menon, Fang Zhou

Strongly Correlated Electrons

Exact SU($N$) symmetry resolution of bosonic Hubbard models: general boson-fermion mappings and flat-band singlet-cluster states

Loïc Herviou

We show how to perform exact diagonalization of SU($N$)-symmetric Bose-Hubbard models separately in each irreducible representation of SU($N$), by exploiting the Howe duality between U($L$) and U($N$). Three structural consequences follow for any lattice and any Hamiltonian built from the U($L$) generators: (i) the spectrum in a given orbital sector is independent of $N$ and of the particle statistics, (ii) the canonical partition functions for bosons and fermions obey the exact identity $Z_{\mathrm{b}}(-N)=(-1)^{N_\mathrm{b}}Z_{\mathrm{f}}(N)$, (iii) with unfrustrated hopping the groundstate is always a color ferromagnet, so that the color-resolved method we introduce is useful to study excited sectors, frustrated lattices and finite temperatures. As applications, we first derive the finite-temperature phase diagram of attractive SU($N$) bosons on few-site rings at large $N$ for arbitrary filling. We then show the emergence of singlet-cluster states from frustrated hopping, the counterpart of fermionic ferromagnetism, with the example of the sawtooth and kagome lattice.
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High Energy Physics (Phenomenology)

Disappearing Tracks from Electroweak Vector Dark Matter at the LHC

Fabián Hernández-Pinto, Patricio Escalona and Alfonso Zerwekh

We study the disappearing-track signature of a spin-1 minimal dark matter candidate transforming in the real five-dimensional representation of $SU(2)_L$ with vanishing hypercharge. Radiative electroweak corrections induce a compressed mass spectrum among the multiplet components, allowing the singly charged state $V^\pm$ to attain a macroscopic lifetime and decay via $V^\pm \to V^0 \pi^\pm$ inside tracking detectors. We recast the ATLAS search for disappearing tracks with the full Run-2 dataset of $137\text{ fb}^{-1}$, originally targeted at long-lived charginos, computing the tracklet reconstruction probability analytically from the published efficiency so that the full lifetime range is covered. The procedure reproduces the ATLAS limits for pure winos within $6\%$ in mass. The Run-2 data exclude quintuplet masses up to $1080\text{ GeV}$ for proper decay lengths $c\tau \simeq 250\text{ mm}$, and $M_V < 630\text{ GeV}$ for a mass splitting of $166\text{ MeV}$. For the radiative mass splitting predicted by the model with a small Higgs-portal coupling, masses between $120\text{ GeV}$ and $240\text{--}300\text{ GeV}$ are excluded. With $3\text{ ab}^{-1}$ and a Run-2-like analysis, the sensitivity would extend to $1750\text{ GeV}$ for vanishing background and to $1530\text{ GeV}$ for a linear extrapolation of the instrumental background.
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Astrophysics of Galaxies

Globular cluster Observations for Luminosity-dispersion Distances (GOLD): Project description and velocity catalogue

K. Fahrion, M. A. Beasley, A. Gvozdenko et al. (+10 more)

We introduce and describe the Globular cluster Observations for Luminosity-Dispersion distances (GOLD) project, which has the principal aim of determining independent distances based on the globular cluster (GC) absolute magnitude-velocity dispersion ($M_V - \sigma$) relation calibrated with Milky Way GCs with Gaia distances. The project comprises observations of GCs in 19 early- and late-type galaxies taken with FLAMES/GIRAFFE on ESO's Very Large Telescope. So far, 17 galaxies have been observed. The spectra cover the wavelength range 8483-9000 AA, including the calcium triplet region at a spectral resolution of $R\sim18,000$. The spectra provide line-of-sight velocities with typical uncertainties of $\Delta v = 1-2$ km s$^{-1}$. Using primarily velocities to separate extragalactic sources from foreground stars, we present here our initial sample of 1062 GCs and 101 ultra-compact dwarf galaxies (UCDs). For more than 650 of these objects we present the first velocity measurement. We discuss the available photometry and size measurements, and show that our velocities are in good agreement with previous studies. Our velocity catalogues are made publicly available. Beyond the principal aim of obtaining precision distances, additional science to be explored with these data includes host galaxy halo dynamics and clustering analysis, mass-to light ratios of GCs and UCDs in the sample, the stellar initial mass function and black hole occupation fraction of the GCs, and chemical abundances from high-dispersion spectra.
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All authors K. Fahrion, M. A. Beasley, A. Gvozdenko, I. Ortega-Casas, A. Ferre-Mateu, F. I. Aros, D. Dold, T. Jerabkova, S. S. Larsen, O. Müller, M. Rejkuba, K. L. Rhode, G. van de Ven

Astrophysics of Galaxies

Stellar discs and intermediate-mass black holes in galactic nuclei II. Fragmenting the disc and forming the S-stars in a live nuclear star cluster

Taras Panamarev and Bence Kocsis

We present direct $N$-body simulations of a stellar disc around the supermassive black hole Sgr~A*, perturbed by an intermediate-mass black hole (IMBH) and embedded in a live nuclear star cluster. A retrograde IMBH with $m_\bullet=2000\,M_\odot$, relative inclination $\theta_\bullet=150^\circ$, and initial semi-major axis $a_\bullet=0.15$~pc breaks the disc into three disc-like components and an angular momentum filament. The stochastic torques of the cluster, together with the IMBH's inward migration, increase the angular separation between these substructures. By ${\sim}5$~Myr, their separations become comparable to those among the observed Galactic-centre young star structures. The innermost ($a\le0.04$~pc) disc stars evolve into an S-star-like population. Relaxation driven by the cluster disperses their orbital planes, excites their eccentricities and depletes the `zone of avoidance' within ${\sim}10$~Myr even without an IMBH. The IMBH further accelerates their orbital-plane reorientation. However, the most eccentric S-stars may require an additional formation channel, such as the Hills mechanism. The distinctive signatures of the IMBH are the well-separated disc components and the eccentricity excitation confined to the radial range swept by its orbit. Dynamical friction from the cluster reduces the orbital size of a $2000\,M_\odot$ IMBH initially at $0.15$~pc by more than a factor of two within $10$~Myr. Prograde IMBHs tend to align with the stellar disc, whereas a $2000\,M_\odot$ retrograde IMBH can anti-align with the radially overlapping disc stars. We also quantify how the IMBH affects the supply of stars to the loss cone and the rates of stellar tidal disruptions and binary separations.
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High Energy Physics (Phenomenology)

Collider and direct detection as key probes of asymmetric dark matter: Signals from a compressed Inert Higgs doublet

David Cerdeño, Miguel Escudero, Pietro Ghedini et al. (+4 more)

The cosmic imbalance of particles over antiparticles may be inherited by the dark matter in a certain class of asymmetric dark matter models. In this article, we thoroughly investigate the signatures of the minimal realization of this idea. In this model a new (stable) inert Higgs, $H'$, plays the role of the mediator that facilitates the asymmetry transfer from the visible to the dark sector. It also constitutes a small dark matter sub-component, while the dominant component stems from a singlet scalar asymmetry. A combination of phenomenological and cosmological constraints requires this new inert Higgs doublet to be quite light $46\,{\rm GeV}<m_{H'}< 580\,{\rm GeV}$ and its spectrum rather compressed, $\Delta M = m_{H^\pm}-m_{H_0} \lesssim 1\,{\rm GeV}$ and $\delta m = m_{A_0}-m_{H_0}\lesssim 5\,{\rm MeV}$. Therefore its charged component can be relatively long-lived on collider length-scales. By recasting searches for compressed Higgsinos at the LHC, we derive new limits on this particle and show that, while at present most of the parameter space for this state is still unconstrained, large and key regions of parameter space will be tested at the HL-LHC by a combination of searches for disappearing charged tracks and displaced soft tracks. Quite remarkably, the lifetime of the charged component of the doublet can be correlated with the dark matter interaction rate at direct detection experiments and we show that the next generation of direct detection experiments has a unique sensitivity to the parameter space in the model. The fact that a small neutral mass splitting is a prediction of the asymmetric setup makes it an interesting candidate to account for the high energy nuclear recoil event recently reported by the LZ experiment. More generally, our detailed phenomenological study holds for any dark matter model involving an inert Higgs doublet with mass below 580 GeV.
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All authors David Cerdeño, Miguel Escudero, Pietro Ghedini, Guilherme Guedes, Thomas Hambye, Abel Muñoz-Navarro, Elena Pressendo

Quantum Physics

Compass in the Mirror: Quantum Backpropagation with the Hopf Ansatz

Ruge Lin and Ranyiliu Chen

A variational quantum state may have many control angles, and its complete gradient contains one derivative for each. The task is to turn access to selected derivatives into a shared finite-shot record for the complete vector. The Hopf ansatz supplies the setting: it constructs any normalized pure state from nested two-way magnitude splits and, for complex states, leaf phases, with one directly programmed angle per split or phase. Earlier Hopf constructions prepare the state, recover coordinates from known amplitudes, and provide indexed derivative access. With a phase-calibrated controlled reflection, the inverse Hopf frame maps each normalized magnitude direction to a computational label, so every all-$X$ outcome contributes to every magnitude derivative. A separate signed leaf record supplies the complex phase block. A checkpoint variant reverses only the suffix below a selected depth and returns that layer's gradient block. For a complete chart with $M$ real-valued parameters, sufficient execution counts are $\mathcal{O}(\log\log M)$ for the global method and $\mathcal{O}(\log M\log\log M)$ for the complete checkpoint schedule at fixed additive coordinate accuracy and confidence. The global saving is record reuse, not a reduction of the $M$-entry output. Under the designated direct-angle schedules, the global method's assigned Hopf CNOT work and input/output-inclusive storage have at most logarithmic overhead relative to a matched scalar evaluation. The same Hopf geometry thus carries a state forward and the objective's complete coordinate response backward.
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High Energy Physics (Theory)

Defect conformal field theories with free-in-the-bulk fermions

Christopher P. Herzog and Daniel Lloyd-Jones

We study codimension-two conformal defects for massless fermions that are free in a four-dimensional bulk, but interact on a two-dimensional defect. The bulk Dirac equation strongly constrains defect conformal field theory data: it fixes the dimensions of operators in the bulk-defect operator product expansion and, for bulk-defect-defect three-point functions, enforces a double-twist relation when only one member of a shadow pair is allowed by unitarity. The lowest modes of monodromy defects provide an important exception, since both shadow partners can be unitary and their three-point functions are instead related by a shadow transform. We illustrate these structures with defect interactions, including an exactly tractable bilinear flow and Gross-Neveu-type quartic couplings. At a perturbative mixed fixed point, we find an explicit interacting example in which the double-twist condition is violated and the two shadow channels combine to give a regular bulk-defect-defect correlation function.
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High Energy Physics (Theory)

Semiclassical state on algebra of observables for de Sitter space and time reversal symmetry

Muxin Han and Yichen Hu

In de Sitter static patch holography, coupling bulk quantum fields to an observer's dynamical clock yields a type II$_1$ von Neumann algebra $\mathcal{M}_+$ of gauge-invariant observables. However, the unique tracial state on this algebra fails to reproduce semiclassical bulk correlation functions. We resolve this issue by introducing a family of heavy-clock states, representing an observer reference frame with heavy inertia. We prove that in the heavy-clock limit, $n$-point correlation functions of gauge-invariant dressed observables reproduce the bulk quantum field correlation functions on de Sitter spacetime. Furthermore, we investigate a generalized observer Hamiltonian $\widehat{H}_{\rm obs}=|\widehat{\pi}|$ that incorporates both forward-running ($\pi\geq 0$) and backward-running ($\pi <0$) clocks. The resulting von Neumann algebra $\mathcal{M}$ of gauge-invariant observables remains a type~II$_1$ factor and is isomorphic to $\mathcal{M}_+\otimes M_2(\mathbb{C})$, where $M_2(\mathbb{C})$ is the algebra of $2\times2$ complex matrices transforming between the two clock orientations. Time-reversal symmetry is implemented in this setting as an anti-unitary operator that exchanges the two clock orientations, yielding a type~II$_1$ von Neumann algebra $\mathcal{F}$ of gauge-invariant, time-reversal-invariant observables. We generalize the heavy-clock state construction to both $\mathcal{M}$ and $\mathcal{F}$, showing that $n$-point correlation functions calculated in heavy-clock states match the corresponding semiclassical bulk correlation functions. Finally, by coupling Einstein gravity to the Brown–Kuchař dust field, we derive the observer Hamiltonian $\widehat{H}_{\rm obs}=|\widehat{\pi}|$ from a perturbative reduction along the observer's worldline in the $G \to 0$ limit. This provides a field-theoretic foundation for the observer model developed in this work.
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Astrophysics of Galaxies

Searching for Nearby Supermassive Black Hole Binaries with GRAVITY

GRAVITY Collaboration: K. Abd El Dayem, N. Aimar, A. Berdeu et al. (+81 more)

We present a systematic interferometric search for close supermassive black hole (SMBH) binaries in 20 nearby type 1 active galactic nuclei (AGN) observed with VLTI/\grav. We investigate parsec-scale asymmetric emission by modeling the squared visibilities and closure phases with a single circular Gaussian component plus a background point source for the central AGN, and searching for additional compact companions through grid-based binary models. The robustness of the search is validated using injection-recovery simulations and point-spread-function diagnostics. Several features are identified in the initial significance maps, but only one candidate out of 20 shows a persistent compact asymmetry, corresponding to an observed incidence of $5\%$. If NGC~3783 is interpreted as a binary AGN, we derive a Poissonian one-sided $1\sigma$ upper limit of $f_{\rm bin}<16.5\%$ for GRAVITY-detectable binaries among bright nearby AGN (K<12.5) at separations of $\sim1$-$100$~pc. Conversely, if the observed asymmetry in NGC~3783 is associated with asymmetric circumnuclear dust emission, the corresponding upper limit on the binary fraction is $f_{\rm bin}<9.2\%$. We compare these results with predictions from the Horizon-AGN simulation, finding comparable binary fractions. We also noted that the expected fraction strongly depends on the assumed distribution of individual SMBH accretion rates within binaries, which is currently unresolved in cosmological models. Our results demonstrate the potential of infrared interferometry to identify parsec-scale binary AGN candidates and motivate future GRAVITY+ observations to expand the sample and follow up known candidates, helping to confirm their nature and distinguish genuine binaries from asymmetric nuclear structures.
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All authors GRAVITY Collaboration: K. Abd El Dayem, N. Aimar, A. Berdeu, J.-P. Berger, G. Bourdarot, W. Brandner, Y. Cao, C. Correia, Q. D'Amato, R. Davies, D. Defrère, A. Drescher, F. Eisenhauer, M. Fabricius, H. Feuchtgruber, S. Flesch, N. M. Förster Schreiber, A. Foschi, Q. Fournier, P. Garcia, R. Garcia Lopez, R. Genzel, S. Gillessen, F. Gonté, X. Haubois, S. F. Hönig, L. C. Ho, M. Houllé, S. Joharle, J. Kammerer, A. Kaufer, P. Kervella, J. Kolb, L. Kreidberg, L. Labadie, S. Lacour, O. Lai, R. Laugier, J.B. Le Bouquin, J. Leftley, R. Li, K. Li, B. Lopez, D. Lutz, F. Mannucci, F. Mang, A. Mérand, F. Millour, M. Montargès, N. Morujão, H. Nowacki, M. Nowak, S. Oberti, J. Osorno, T. Ott, C. Paladini, S. Pappert, T. Paumard, K. Perraut, G. Perrin, R. Petrov, P. O. Petrucci, N. Pourré, S. Rabien, D. C. Ribeiro, S. Robbe-Dubois, M. Sadun Bordoni, J. Sanchez-Bermudez, J. Sauter, M. Scialpi, J. Scigliuto, J. Shangguan, T. Shimizu, F. Soulez, C. Straubmeier, E. Sturm, M. Subroweit, C. Sykes, L. J. Tacconi, P. Thévenet, I. Urso, F. Vincent, J. Woillez, G. Zins

Astrophysics of Galaxies

A first view of interstellar Fe-bearing dust grains with XRISM

I. Psaradaki, L. Corrales, E. Costantini et al. (+8 more)

Understanding the reservoirs of iron (Fe) in our Galaxy is crucial for probing the mechanisms that drive dust grain growth in the interstellar medium (ISM). High-resolution X-ray absorption spectroscopy offers a powerful tool to investigate the chemistry of dust grains, particularly those containing Fe, through spectroscopic features near photoabsorption edges known as X-ray Absorption Fine Structures (XAFS). With the Resolve spectrometer aboard XRISM, we can now examine the Fe K-edge (7.1 keV) owing to its improved spectral resolution in this energy range. This enabled us to probe the dust grain chemistry in high Galactic column densities. In this work, we present a pilot study on dust grain chemistry through the Fe K-edge of the XRISM Performance Verification target GX 340+0. This source is a persistently bright low-mass X-ray binary with a hydrogen column density of 6.6x10^22 cm^-2 along the line of sight, providing sufficient optical depth at the Fe K-edge. By fitting combined dust and gas models, we find that Fe is depleted by 95% into dust along the line of sight towards the source. Moreover, we find evidence that 38% of the solid-phase Fe is in metallic iron, 47% in iron sulfides, and the remainder in silicates. The large contribution from metallic iron and iron sulfides differs from what is typically inferred from X-ray studies of diffuse ISM and may suggest that that these compounds become more significant reservoirs of Fe in higher column density Galactic sightlines.
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All authors I. Psaradaki, L. Corrales, E. Costantini, M. Mehdipour, D. Rogantini, H. Takahasi, R. Ballhausen, P. Chakraborty, T. Nakagawa, R. K. Smith, S. Zeegers