Nuclear Experiment
The role of strangeness and baryon enhancement in heavy-quark hadronisation from pp to Pb$-$Pb collisions with ALICE
Fabrizio Chinu
In this contribution, a combined study of charm-
meson and charm-
baryon production with ALICE is presented. The $\Lambda_{\mathrm{c}}^{+}/\mathrm{D^{0}}$ ratio in pp collisions at $\sqrt{s} = 13.6$ TeV and the first measurement of the
nuclear modification factor of $\Xi_{\mathrm{c}}^{0}$
baryons in Pb$-$Pb collisions at $\sqrt{s_\mathrm{NN}} = 5.02$ TeV are reported. Furthermore, measurements of the $\mathrm{D_s^+/D^+}$ production ratio from low-multiplicity pp collisions at $\sqrt{s} = 13.6$ TeV to Pb$-$Pb collisions at $\sqrt{s_\mathrm{NN}} = 5.36$ TeV are presented. Lastly, the first measurement of the $p_\mathrm{T}$-differential $\mathrm{D_{s1}(2536)^+/D_s^+}$ yield ratio is shown.
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Fluid Dynamics
LES of iron-powder combustion in a jet-in-hot-coflow burner - Insights on flame structure and ignition characteristics
Shyam Hemamalini and XiaoCheng Mi
Micron-sized iron powders are a rapidly advancing novel energy storage technology. In order to improve the design of real-world iron-powder combustors, adequate understanding of the ignition behavior in such settings is necessary. In this work, a jet-in-hot-coflow (JHC) burner designed by Hameete et al. (2024) to test ignition of iron particles in lab-scale turbulent flames is modeled numerically using LES and Lagrangian point-particles. The JHC burner is simulated in two different modes–an open flame and an enclosed flame–similar to the experimental reference. Two iron-oxidation-rate models–the first-order model and
oxide-layer model–are used to examine the effect on capturing the ignition behavior. For the radiative heat transfer between the two phases, a simplified Stefan-Boltzmann approximation model and the P1 model are considered, similar to Ramaekers et al. (2025). Analysis of flame structure indicates ignition in the circumference of the jet, aided by the break-up of the coflow. At higher $T_\mathrm{coflow}$, ignition onset and oxidation completion is earlier prior to jet break-up. Minimum coflow temperature for particle ignition with the
oxide layer model is $1125\mathrm{K}$ with complete oxidation at $1250\mathrm{K}$, and for the first-order model at $800\mathrm{K}$ and $900\mathrm{K}$, respectively. Both of these results do not match the experimental results of Hameete. Oxidation degree is predictably higher for enclosed flames. For the chosen particle distribution, the P1 model exhibits higher radiative heat loss and results in a slightly lower oxidation degree. Analysis on particle ensembles with partial oxidation shows that the overall oxidation degree at a sufficient height above the nozzle reflects particle ignition probability. Further analysis in regards to particle size shows ignition failure is more prevalent in larger particles.
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Solar and Stellar Astrophysics
Probing magnetic fields in stars: A 2D oscillation framework including rotation and magnetism
Antoine Fort, Rhita-Maria Ouazzani, Lucas Barrault et al. (+2 more)
Understanding the role of internal
magnetic fields in
stars remains a major challenge for the description of angular momentum transport and
stellar evolution. It is therefore essential to probe these
magnetic fields within the
star, and asteroseismology provides a powerful means to do so. In this work, we present a new implementation of the 2D oscillation code ( ), which incorporates the effects of both
stellar rotation and
magnetic fields. Adaptive Code of Oscillations towards Realistic modeling The code has been rendered modular, making it possible to specify the set of equations to solve and the assumptions through a symbolic calculus approach. The full set of adiabatic, non-radial pulsation equations is solved using a spectral approach for the angular part of the modes and high-order finite differences for the radial part. As a first step, we focus on a
magnetic field that is purely toroidal and axisymmetric about the
star's rotation axis. The numerical results are compared against first-order perturbative predictions in the weak-field regime and with the traditional approximation of rotation and magnetism (TARM) in the case of stronger
magnetic fields. We validate this new implementation of against perturbative and TARM approaches, showing good agreement and demonstrating the robustness of the code. The breakdown of these methods provides general validity limits. We show that internal
magnetic fields leave signatures in the period spacing of g modes. These features provide a promising seismic diagnostic to probe deep
stellar magnetism in {\gamma} Dor
stars. Future work will aim to extend this framework to more realistic
magnetic field
topologies and a broader range of pulsating
stars, including red
giants.
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All authors Antoine Fort, Rhita-Maria Ouazzani, Lucas Barrault, Louis Manchon, Ludovic Petitdemange
Statistical Mechanics
A Generalized Model for Disordered Random Sequential Adsorption with Charge-Dependent Deposition
G. Palacios and A. M. S. Macêdo
We generalize a one-dimensional random sequential adsorption model (RSA) of charged unit segments in which the deposition position follows a beta kernel determined by the charges bounding the available gap and those of the incoming particle. The interaction parameter \(0\leq\lambda<1\) interpolates between uniform car parking and strongly localized deposition. We derive a four component generating function equation that provides exact recursions for the complete occupation statistics, although only the mean and variance are analyzed in detail here. Exact finite-shell solutions serve as
benchmarks for the Gauss–Jacobi quadrature and Monte Carlo simulations. We prove that, although boundary charges affect finite size behavior, the four boundary states have the same asymptotic mean and variance densities, consequently, we prove that the jammed density is self-averaging. Numerical results show that charge selectivity increases the coverage, especially for mixtures dominated by opposite endpoint charges, which also exhibit strongly reduced fluctuations near \(\lambda=1\). The model provides a tractable connection between uniform RSA, dynamically generated disorder, and interaction-driven deposition.
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Instrumentation and Methods for Astrophysics
Development, Configuration and Performance Characterization of a Scalable BETA ASIC-Based Readout System for Multi-Channel SiPM Detectors
Giulio Lucchetta, Keerthana Rajan Lathika, Benjamin Nobre Hauptmann et al. (+17 more)
We present the design, configuration, and performance characterization of a scalable readout system based on the BETA application-specific integrated
circuit (ASIC), developed to meet stringent requirements on noise, linearity, dynamic range, and power consumption for multi-channel silicon photomultiplier (SiPM) detectors in spaceborne instrumentation. The readout electronics consists of modular interface boards (FIBs) hosting multiple BETA ASICs and controlled by a field-programmable gate array (FPGA), which provides configuration, data acquisition, and global trigger generation. Multiple BETA FIBs were tested in a dedicated optical setup enabling simultaneous readout of a large number of channels. The system performance was evaluated using three S13552-10 SiPM arrays manufactured by Hamamatsu for the FIT detector, a scintillating-fiber tracker developed for charged
cosmic-ray particle tracking and charge measurement in the HERD mission. We describe the configuration procedures and performance measurements of the readout system, including gain calibration, linearity characterization, and threshold response. In addition, we present the development of a global internal trigger logic for the identification of ionizing particles in the FIT detector. The results demonstrate the stability, scalability, and suitability of the developed BETA-based readout system for large-scale multi-channel SiPM detector applications in space experiments.
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All authors Giulio Lucchetta, Keerthana Rajan Lathika, Benjamin Nobre Hauptmann, Philipp Azzarello, Oscar Blanch, Juan Boix, Laia Cardiel, Arturo Castaño Gallardo, Albert Espinya, Jennifer Maria Frieden, David Gascon, Daniel Gubermann, Kimberly Sarah Keyser, Manel Martinez, Joan Mauricio, Marina Orta-Terré, Chiara Perrina, Javier Rico, Andreu Sanuy, Monong Yu
High Energy Physics (Phenomenology)
Searching for vectorlike $T$ quarks in the $T\to tZ$ channel at a future muon-proton collider
Yin-Hao Gao and Yao-Bei Liu
We investigate the discovery potential of a singly produced vector-like top
quark $T$ in the $T\to tZ$ decay channel at future
muon-
proton ($\mu p$)
colliders, considering three
benchmark center-of-mass energies: $\sqrt{s}=5.29$, $6.48$, and $9.16$~TeV. The baseline signal final state consists of a semileptonic top decay $t\to bW\to b\ell\nu$ and a hadronic $Z\to q\bar{q}$ decay, where the collimated
quark pair from the $Z$
boson is reconstructed as a single large-radius fat jet $J$. Full detector-level Monte Carlo simulations are performed for both the signal process and the dominant Standard Model backgrounds. We derive the $5\sigma$ discovery contours and the $95\%$ confidence level exclusion limits in the two-dimensional parameter space spanned by the VLQ mass $m_T$ and the effective coupling $g^*$. A comparison with the $T\to Wb$ channel and with searches at other
collider facilities reveals that the $T\to tZ$ decay mode provides complementary sensitivity and offers unique advantages for probing high-mass vector-like $T$
quarks in the boosted jet
topology.
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High Energy Physics (Phenomenology)
Investigation of S-wave tetraquark bound and resonant states with all Jacobi coordinates
Xin-He Zheng, Yao Ma, Liang-Zhen Wen et al. (+1 more)
We systematically explore the $S$-wave tetraquark systems $Qs\bar{n}\bar{n}$, $QQ\bar{n}\bar{n}$, $QQ\bar{Q}\bar{Q}$, and $ss\bar{s}\bar{s}$ ($Q=c,b$; $n=u,d$) within the constituent
quark potential model. We incorporate all K-type Jacobi coordinates in addition to the conventional H-type configurations, optimize the basis expansion via a
stochastic parameter generation strategy, and apply the complex scaling method to identify bound and resonant states. Our calculations demonstrate that while conventional H-type configurations suffice for low-lying states such as the $T_{cc}(3875)^+$ molecular candidate, the inclusion of K-type configurations becomes important for extracting highly excited resonances, allowing higher-energy resonances absent in H-only calculations to be identified. Furthermore, we identify resonance candidates for the $T_{cs0}(2900)$, $X(6900)$, and $X(7200)$, whereas the absence of fully-strange compact poles below 2.6 GeV challenges the interpretation of $\phi(2170)$ and $X(2370)$ as $S$-wave compact $s s \bar{s} \bar{s}$ tetraquarks.
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All authors Xin-He Zheng, Yao Ma, Liang-Zhen Wen, Shi-Lin Zhu
Fluid Dynamics
Unsteady airfoil aerodynamics in attached flow: From unsteady thin airfoil theory to wind turbine application
Ang Li, Mac Gaunaa and Georg Raimund Pirrung
Attached-flow unsteady aerodynamics underpin the dynamic stall models used in wind turbine aerodynamic and aeroelastic codes, particularly over the outboard blade region that dominates power production and loading. Here, angle of attack and relative velocity vary while the flow remains predominantly attached. A complete engineering model combines airfoil polar lookup, shed-wake
memory, non-circulatory loads, consistent force definitions, and separated-flow dynamics. Although the underlying theory is classical, existing descriptions do not provide a complete and internally consistent implementation route for these attached-flow contributions in wind turbine solvers. This work formulates the attached-flow contributions as lift, drag, and moment coefficients for blade-element momentum (BEM), lifting-line (LL), and actuator-line (AL) methods, for use with 2-D airfoil polars from measurements or CFD. Starting from classical unsteady thin-airfoil theory, circulatory and non-circulatory loads are derived in coefficient form and key modeling choices are clarified. Shed-wake
memory is formulated using downwash velocity rather than angle of attack as the aerodynamic state variable. Rotor-level implementation is verified using two cases. A coned straight-blade case provides a cross-method
benchmark and quantifies thrust and power errors caused by omitting three required contributions. Lift-direction projection has the largest influence on power, while omitting the mid-chord heaving-acceleration term removes the non-circulatory normal-force cancellation and produces a thrust error. A zero-onset-flow vertical-axis wind turbine (VAWT) case verifies that, in the ideal thin-airfoil limit, all circulatory and non-circulatory contributions cancel, yielding zero total rotor torque.
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Mathematical Physics · Cross-listed from math.DG
Reduction of symmetric time-dependent Hamiltonian systems I: presymplectic principal $\mathbb{R}$-bundles
C. Benítez, D. Iglesias Ponte, J. C. Marrero et al. (+1 more)
The reduction of mechanical presymplectic structures and its application to the reduction of time-dependent
Hamiltonian systems were developed in a recent paper (Gutiérrez Sagredo et al, 2025). This approach overcomes some limitations of the original Albert reduction (Albert, 1989). In this paper we will describe the reduction of time-dependent
Hamiltonian systems using the extended formalism. This process combines cotangent bundle reduction with reduction of presymplectic structures of corank 1 and 2. These results generalize previous work (Lacirasella et al, 2012), in the same direction. Several examples will be presented to illustrate the theory from this new perspective.
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All authors C. Benítez, D. Iglesias Ponte, J. C. Marrero, E. Padrón
High Energy Physics (Phenomenology)
Color screening versus thermal decay as the mechanism of $\Upsilon$ suppression in high energy nuclear collisions
Yida Yang, Baoyi Chen, Jiaxing Zhao et al. (+1 more)
To clearly identify the mechanism behind the suppression of heavy quarkonium in relativistic heavy-ion collisions, we study $\Upsilon$ production at RHIC energies by solving its transport equation driven solely by the suppression rates. By calculating the
nuclear modification factor and comparing it with experimental data, we find that the sudden suppression governed by the color-screening temperature cannot simultaneously describe both the ground and excited states of the $\Upsilon$, whereas the continuous suppression induced by thermal decay successfully reproduces all the $\Upsilon$ measurements. This provides strong evidence that inelastic scatterings with thermal partons, rather than color screening, dominate quarkonium suppression in heavy-ion collisions.
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All authors Yida Yang, Baoyi Chen, Jiaxing Zhao, Pengfei Zhuang
Instrumentation and Detectors
Full-field fluorescence computed tomography (F3CT) using a calibrated virtual cone-beam pinhole geometry
Thomas Zillhardt, Yunhui Chen, Alexander Rack et al. (+4 more)
We present F3CT, a synchrotron-based hyperspectral full-field fluorescence computed
tomography technique that avoids raster scanning by combining a pinhole aperture with an energy-resolving 2D detector. A virtual cone-beam model and two-stage calibration-reconstruction workflow enable 3D elemental mapping under full-field illumination. The method is demonstrated on biological and geological specimens, resolving silver-stain distributions in zebrafish tissue and high-energy fluorescence signatures in rock cores. Phase-contrast tomograms acquired sequentially under the same experimental geometry provide co-registered structural context. F3CT provides a high-throughput route to 3D XRF imaging and establishes a foundation for correlated structural and chemical
tomography, with potential for future in-situ and operando implementations.
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All authors Thomas Zillhardt, Yunhui Chen, Alexander Rack, Matthew Veale, Matt Wilson, Philip J. Withers, Nicola Viganò
Materials Science
Phenomenological Growth Regimes in Liquid-Precursor CVD of MoS$_2$ on Functional Substrates
Osamah Kharsah, Kilian Mouchel, Yossarian Liebsch et al. (+8 more)
The integration of two-dimensional transition-metal dichalcogenides (TMDCs) onto functional substrates remains constrained by
stochastic vapor-phase growth dynamics. Here, we show that
liquid-phase precursor chemical vapor deposition (CVD) of MoS$_2$ introduces growth conditions that are consistent with a substrate-influenced reaction-
diffusion process. By utilizing pre-growth
spin-coated MoO$_3$ intermediates across a diverse crystalline library (sapphire, SrTiO$_3$, rutile TiO$_2$, MgO, and 6H-SiC), we find that substrate-dependent variations in precursor wetting, surface chemistry, and inferred mass-transport constraints correlate with distinct growth morphologies. These substrate-dependent growth regimes are interpreted in terms of reduced effective lateral growth length on SrTiO$_3$, possible precursor anchoring on TiO$_2$, likely chemical surface restructuring on MgO, and possible step-edge growth on SiC. Raman and photoluminescence spectroscopy reveal substrate-dependent variations in vibrational and optical response that correlate with differences in strain, charge environment, and dielectric screening. Ultimately, this work highlights a substrate-dependent reaction-
diffusion framework as a potentially useful route for tuning the structural and optical properties of large-area 2D materials.
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All authors Osamah Kharsah, Kilian Mouchel, Yossarian Liebsch, Cathy Sulaiman, Joel Verlande, Anke Hierzenberger, Abdallah Alghazali, Clara Grygiel, Stéphane Guillous, Henning Lebius, Marika Schleberger
Materials Science
Nanolamellar Hybrid High-Entropy Alloys with Superior Micromechanical Properties
Shivam Dangwal, Yoji Mine, Shohei Ueki et al. (+5 more)
Metallic materials with nanolamellar structures, such as pearlitic steels, exhibit high strength with appropriate ductility. Considering the potential ability of such nanolamellar structures to break the traditional strength-ductility trade-off in metallic
alloys, this study aims at developing a unique nanolamellar structure with superior micromechanical properties by combining two different high-
entropy alloys (HEAs). Al0.1CoCrFeNi with the face-centered cubic (FCC) structure is combined with TiZrHfNbTa with the body-centered cubic (BCC) structure using high-pressure torsion (HPT) of half discs of each
alloy. That way, a layered hybrid structure was formed, with layer thickness down to about 61 nm. The BCC/FCC nanolamellar hybrid structure exhibits an exceptional combination of properties with an ultimate tensile strength of 2.4 GPa, a maximum bending strength of 4.0 GPa, and a hardness of 740 Hv, while retaining some ductility/plasticity under both tensile and bending loads. Detailed analyses by synchrotron diffraction, electron microscopy and atom probe
tomography suggests that these high strength and hardness, which are superior to those of nanostructured HEAs, result from: (i) extreme grain boundary strengthening from nanograins with a mean size of 22 nm, (ii) presence of defects such as dislocations in FCC and BCC, stacking faults in FCC and twins in FCC, and (iii) interphase hardening from BCC/FCC nanolamellar boundaries with about 30% contribution to the total hardness. This work demonstrates that combining two HEAs using HPT into a defect-rich hybrid nanolamellar composite forms a promising synergy of ultrahigh strength and reasonable ductility/plasticity.
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All authors Shivam Dangwal, Yoji Mine, Shohei Ueki, Xavier Sauvage, Fabien Cuvilly, Liliana Romero Resendiz, Muhammad Naeem, Kaveh Edalati
General Relativity and Quantum Cosmology
Global structure of Kerr-Newman-BR spacetime
Hryhorii Ovcharenko
We conduct an investigation of the global structure of Kerr-Newman-BR spacetime and its various subcases such as Schwarzschild-BR spacetime. In this work, we extend the result of our previous studies, where we found that $r\to \infty$ is not the proper conformal infinity. By using the reciprocal coordinate $y=1/r$, we show that the whole family of Kerr-Newman-BR spacetimes can be continuously extended through the surface $r\to \infty$. However, the conformal structure after passing $r\to\infty$ strongly depends on the type of spacetime one is considering (either rotation is present, or not) and on the polar direction one chooses to be fixed (namely, whether we consider generic polar angle $\theta$, or we focus on the behaviour near the equatorial plane $\theta=\pi/2$, or near the poles $\theta=0,\pi$). Finally, we discuss the universality of such a continuous extension.
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Mesoscale and Nanoscale Physics
Rapid Charge Stability Diagram Generation from Device-level Modeling of Semiconductor Quantum Dots
Ron Nodel, David W. Kanaar, Connor Nasseraddin et al. (+5 more)
Self-consistent Schrödinger-Poisson calculations are a powerful tool for predicting the behavior of layered
semiconductor quantum dot devices. However, characterization of charge stability diagrams through fully simulated gate-voltage sweeps is computationally expensive. Combining a Multi-Domain Multi-Model (MDMM) approach with an automated tuning routine, we identify gate voltages associated with selected charge configurations. This small set of self-consistent simulations can be augmented with Full Configuration Interaction (FCI) energy calculations to extract charging energies, lever arms, and interdot Coulomb interactions to directly parameterize a Hubbard model for rapid charge stability diagram generation. For an Intel Tunnel Falls Si/SiGe device, we demonstrate the Hubbard model's ability to reproduce charge stability diagrams at a fraction of the computational cost in comparison to voltage bias sweeps. We further compare the simulated diagrams to experimental data and demonstrate qualitative agreement. Our result represents a step towards predictive digital twin models for
semiconductor quantum dot devices. Finally, we apply this workflow towards lever arm engineering in a second device, demonstrating that the method extends to multiple architectures.
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All authors Ron Nodel, David W. Kanaar, Connor Nasseraddin, Tim J. Wilson, Hong-Wen Jiang, Jason R. Petta, Chris Anderson, Mark F. Gyure
Optics
Quantum many-body effects in the optical response of ideal thin films
David Trejo-Garcia, Tapio T. Rantala, Marco Ornigotti et al. (+1 more)
We study
quantum many-body effects in the long-wavelength optical response of confined electrons at finite temperatures. We simulate homogeneous electron gas confined in one dimension into a slab of nanoscale thickness. We demonstrate how the slab boundaries break down the ideal Drude response of free charge carriers, giving rise to scattering effects due to both the surfaces and
quantum many-body interactions. We use a recent path-integral Monte Carlo (PIMC) approach developed in [Tiihonen et al. Phys. Rev. A 113, 053711] to quantify these effects in high accuracy. We perform phenomenological fits to Drude and Drude-Lorentz models parameters, manifesting various trends of the optical response with physical parameters like density and temperature, and numerical effects like finite size and the
quantum statistics.
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All authors David Trejo-Garcia, Tapio T. Rantala, Marco Ornigotti, Juha Tiihonen
Cosmology and Nongalactic Astrophysics
Guide for the Hubble Tension: Mid-Time Solutions and Generalized PAge Parameterizations
Jing-Yi Jia, Da-Chun Qiang and Hao Wei
In cosmology, the Hubble tension has become one of the most serious challenges in the last decade. Assuming that all the observational data are right, one of the ways out is to modify the standard $\Lambda$CDM cosmology. In the literature, the theoretical modifications are mainly made in the early and the late/local universes. But on both sides, some no-go arguments have been proposed recently. In particular, the general no-go arguments for the late-time modifications are mainly based on the PAge parameterization. In the present work, we note that there are some flaws in the (original) PAge parameterization, and then propose various generalized PAge (GPAge) parameterizations, which can be extended to $z>z_{\rm CMB}$ and hence the
cosmic microwave background (CMB) can be taken into account, while they are also more accurate at low
redshifts. With these GPAge parameterizations, we revisit the Hubble tension by using not only the late-time observations but also the observational data of CMB. We find that the Hubble tension could be alleviated (or even resolved) in GPAges significantly different from the standard $\Lambda$CDM cosmology, while they are overwhelmingly preferred over $\Lambda$CDM by the observational data in terms of all the information criteria. Surprisingly, we find that the new physics in the mid-time might be the key to resolve the Hubble tension.
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Nuclear Experiment
Lifetime measurements in neutron-rich odd-A yttrium isotopes ($^{93-99}$Y): Investigation of shape coexistence and the intertwined quantum phase transition
A. Pfeil, N. Gavrielov, U. Köster et al. (+9 more)
Lifetimes of 16 excited states in the
neutron-rich odd-$A$
nuclei $^{93-99}$Y were measured using fast-timing $\gamma$-$\gamma$ coincidence spectroscopy with fast scintillation detectors at the LOHENGRIN
recoil separator. Particular
attention is given to the region around $N \approx 59$, where rapid changes in
nuclear deformation and shape coexistence occur. The lifetimes, determined using the generalized centroid difference method, are compared with interacting
boson-
fermion model calculations with configuration mixing, in which the odd-$A$ yttrium isotopes are described as a
proton coupled to a bosonic core containing normal and intruder configurations. The results provide new constraints on theoretical descriptions of shape coexistence and structural
evolution in
neutron-rich
nuclei near $A \approx 100$, particularly for odd-$A$ systems where experimental information remains limited.
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All authors A. Pfeil, N. Gavrielov, U. Köster, Y. H. Kim, N. Cieplicka-Oryńczak, J. Dudouet, A. Esmaylzadeh, Ł. W. Iskra, M. Ley, J.-M. Régis, D. Reygadas, J. Jolie
Solar and Stellar Astrophysics
Search for magnetic fields in seven slowly rotating A stars
Pablo de Frutos Rull, Coralie Neiner, Jonathan Labadie-Bartz et al. (+3 more)
A small fraction of A-type
stars host strong fossil
magnetic fields. Identifying them relies on indirect indicators such as chemical peculiarities, slow rotation, and rotational modulation, which are also shared by non-
magnetic stars. Assessing their reliability is essential for future surveys. We magnetically characterise seven slowly rotating, chemically peculiar A-type
stars selected through two complementary strategies. Three were selected from abundance analysis combined with potential intrinsically slow rotation, and four from a spectral depression at 5200 Angstrom combined with rotational modulation in TESS photometry. We obtained high-resolution spectropolarimetry, applied least squares deconvolution, and measured longitudinal field strengths for detections. For non-detections, we derived upper limits on polar field strength and evaluated the critical fields of Zahn and Spruit. We detect
magnetic fields in all four
stars selected via the spectral depression and photometric criterion, with longitudinal field strengths of approximately 145-2900 G, while none of the three
stars selected via abundance and slow rotation shows a Zeeman signature. Combined upper limits for two non-detections lie below or near the
magnetic desert boundary, but only one is also below the critical fields required for rigid rotation. The non-detections are most naturally interpreted as Am
stars. Among the detections, HD 63843 stands out as a
magnetic $\delta$ Scuti pulsator, promising for magneto-asteroseismology. In conclusion, slow rotation combined with chemical peculiarity alone does not reliably trace large scale
magnetic fields, whereas adding the 5200 Angstrom depression and stable rotational modulation in space photometry appears to select
magnetic A-type
stars with high efficiency, providing a practical guideline for future spectropolarimetric surveys.
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All authors Pablo de Frutos Rull, Coralie Neiner, Jonathan Labadie-Bartz, Frédéric Royer, Richard Monier, Keegan Thomson-Paressant
High Energy Physics (Theory)
Revisiting the $U(1)$-$CP$ tension in QCD from a 1PI-action perspective
Paolo Di Vecchia, Francesco Sannino, Graham M. Shore et al. (+2 more)
We discuss the tension one encounters in trying to solve, simultaneously, the $U(1)$ and strong-$CP$ problems in QCD with light
quarks and a small $\bar{\theta}$ angle within QCD itself. We do so by considering the low-energy expansion of a $1$PI effective action $\Gamma$, a functional of a properly chosen set of gauge-invariant (composite) operators. After enforcing Ward-identity constraints on $\Gamma$, we prove, under minor assumptions, that $CP$ violation at small non-vanishing $\bar{\theta}$ can be avoided only if the anomaly-induced contribution to the pseudoscalar mass
matrix is completely negligible when compared to its non-anomalous counterpart - that is, only if the $U(1)$ problem is not solved. The topological susceptibility in QCD and a precise generalization of the one in pure Yang-Mills theory emerge as the most important players in establishing the above tension and in determining the corrections to various known results at leading order in $\bar{\theta}$.
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All authors Paolo Di Vecchia, Francesco Sannino, Graham M. Shore, Gabriele Veneziano, Shimon Yankielowicz
Quantum Physics
Role of the Drive in Mediating Correlations Between Two Qubits Through a Shared Dissipative Cavity
Nozhat Ghaseminezhad, Vahid Ameri and Alidad Askari
Using a numerically exact master equation, we demonstrate that two
qubits, coupled solely through a shared damped, driven cavity, can become correlated. The drive influences both the amount and the type of correlation. For parametric, coherent, and resonantly modulated drives, the
qubits develop
quantum discord that increases with cavity temperature, while the logarithmic negativity remains numerically zero. This indicates the presence of discord without
entanglement. In contrast, a time-modulated parametric drive is the only one that generates genuine two-
qubit entanglement, achieving \(E_\mathcal{N} \simeq 0.15\) and concurrence \(\simeq 0.16\) at \((\eps, \gamma) = (0.3, 0.2)\), which rises to \(E_\mathcal{N} \simeq 0.32\) in the weak-coupling, moderate-damping region. Heating eventually destroys this
entanglement around \(n_{\mathrm{th}} \simeq 0.2\), while discord continues to grow, resulting in a temperature-driven transition from
entanglement to discord within a single drive. Moreover, the parametric drive offers the best protection for single-
qubit coherence, unlike the coherent and modulated drives. An adiabatic-elimination model indicates that the cavity generates an effective coupling and a collective dephasing channel, both of which increase with temperature, explaining the observed discord without
entanglement.
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Atomic Physics
Coherently Enhanced Cherenkov Radiation by Highly Relativistic and Ultra-Compact Electron Beams
S. Kim, C. Müller and A. B. Voitkiv
Cherenkov radiation is emitted when charged particles penetrate dielectric media with velocity higher than the speed of light in the medium. Recent developments in
plasma-based accelerator research enable creation of highly relativistic electron beams with femtosecond length and tens of micrometer scale radii, at energies of up to several GeV. Here, we consider Cherenkov radiation emitted by such extreme beams penetrating a gas target with refractive index very close to one. We demonstrate coherent enhancement in the emitted Cherenkov radiation up to the optical or even near-ultraviolet regime, which is due to the high beam energy and density. We also explore the dependence of the coherently enhanced Cherenkov radiation spectrum on the beam shape.
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High Energy Physics (Phenomenology)
HEPLocalAgent 1.0: Running Collider Simulations from Plain-Language Requests on Your Own Computer
Aadarsh Singh and Sudhir K. Vempati
We present HEPLocalAgent, an open source local interface that builds a bounded class of
collider simulation workflows from natural
language requests. A locally served
language model proposes a typed workflow representation, and deterministic software then restores recognized user stated quantities, builds the HEP tool inputs, validates the supported workflow, and presents the artifacts for approval before execution. In a same response comparison on 47 evaluable model request cases, the first structured proposal gave 7 unmodified artifacts satisfying the external
benchmark scorer, against 19 after the full deterministic pipeline. Under the fixed representation normalization defined by the
benchmark, the counts were 11 and 43. The direction of improvement is unchanged. The gap between the two views arises because the released builder and the
benchmark scorers disagree on three bookkeeping conventions, namely launch form, two fixed control lines, and the output directory name, not on physics content. Four of seven approved workflows ran to completion on the managed local software stack, with cross sections consistent between repeats. In a separate challenge set, 57 of 96 problematic requests still reached the approval stage after part of the request was dropped, defaulted, or reinterpreted. No tested unsafe payload was retained in an executable artifact before the approval gate, but this does not establish operating system level containment. The deterministic backend supports MadGraph, Pythia8, Delphes, and a restricted MadAnalysis 5 plan. Reliable natural
language routing to the MadAnalysis stage was not demonstrated in the tested examples. Version 1 should therefore be seen as an inspectable, validation gated workflow constructor requiring expert approval rather than an autonomous or scientifically self validating
agent.
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Materials Science
QUBO-Compatible Active Learning for Inverse Design of High-Entropy Alloys
Giorgio Silvi, Kirsten Bark, Rolando Reiner et al. (+5 more)
Machine-learned forward models can rapidly predict
alloy properties, but their use for inverse design remains challenging when the search should also retain compatibility with quadratic unconstrained binary optimization (QUBO). Here, we develop a QUBO-compatible active-learning framework for inverse design of high-
entropy alloys using a pretrained graph-neural-network predictor as a fixed property oracle. A property-guided binary variational autoencoder provides a binary latent representation, while an ensemble of quadratic factorization machines guides candidate selection. We systematically
benchmark the framework through controlled latent-space ablations and comparison with direct composition-space optimization. The results show that candidate generation is a major determinant of search performance: local perturbations around previously high-performing latent codes provide the largest workflow-specific improvement, while surrogate-based selection further prioritizes candidates within the enriched search pool. The resulting QUBO-compatible workflow remains competitive with strong classical optimization strategies, although a composition-space genetic
algorithm achieves the highest mean score. Finally, the learned quadratic surrogate can be exported directly as a QUBO. These results show that effective data acquisition can be separated from the final QUBO optimization endpoint, providing a benchmarked route for QUBO-compatible data-driven materials inverse design.
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All authors Giorgio Silvi, Kirsten Bark, Rolando Reiner, Nicolas Vogt, Thomas Plehn, Daniel Barragan-Yani, Marc Landmann, David Melching
Materials Science
Interplay between crystal structure and magnetism in CeCrB$_4$
Mirosław Werwiński, Andrzej Szajek and Andrzej Kowalczyk
CeCrB$_4$ belongs to the family of MTB$_4$ ternary metal borides, some of whose
magnetic phases have recently been identified as
quantum spin dimers. Employing density functional theory within the GGA+$U$ framework, this work investigates the key ground-state properties of this system, including its
ferromagnetic ground state, the mixed-valence nature of cerium, and the charge transfer from the cationic cerium–chromium layers to the anionic boron layers. In particular, we focus on elucidating the bonding mechanism within the structurally embedded Cr-Cr dimers. Specifically, we evaluate a previously proposed interpretation that the localized Cr $3d_{z^2}$ states are molecular-like bonding and antibonding states. The calculated dependence of the $3d_{z^2}$ electronic structure on the intra-dimer distance correlates with the level-splitting characteristics known for classical homonuclear diatomic molecules.
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Quantum Physics
Direct Adaptive Certification of High-Dimensional Entanglement with Bell Tests
Xu Kang Tan, Jesvita Menezes, Sanjan D. Murthy et al. (+1 more)
Entangled
photons play a crucial role in
quantum applications, and determining and characterising their
entanglement is vital to using them effectively. High-dimensional entangled states offer richer possibilities, but their additional measurement degrees of freedom make them increasingly demanding to characterise. However, adaptive Bell-test methods based on complex simultaneous perturbation
stochastic approximation (CSPSA) have so far focused mainly on
qubits. Here we numerically investigate a Bell-inequality-violation-based method for detecting
entanglement in unknown
quantum states. We extend CSPSA to high-dimensional Bell testing by using the Collins-Gisin-Linden-Massar-Popescu (CGLMP) inequality for bipartite qudits. The resulting protocol can detect Bell-nonlocal correlations in unknown entangled states, whether pure or mixed, without first reconstructing their density
matrix. Using 100 optimisation iterations in each of 100 independent finite-shot runs per number of dimensions d, we demonstrate certified CGLMP violations throughout d=2-8. For isotropic mixed states tested at a visibility of just 0.05 above the standard-
Fourier violation threshold, we likewise observe confidence-certified CGLMP violations throughout the range of d studied. We compare this direct
stochastic approach with
quantum state
tomography, the standard method for characterising an unknown state. In the matched
benchmark, CSPSA uses fewer measurement configurations per attempt from d=6, whereas
tomography requires fewer detected pairs per certified result through d=8. We also derive the phase dependence of the CGLMP parameter and clarify the features of its landscape that govern the adaptive search. Because the measurement-setting cost of each CSPSA iteration is independent of dimension, the method offers a particularly attractive route to the certification of high-dimensional
entanglement.
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All authors Xu Kang Tan, Jesvita Menezes, Sanjan D. Murthy, Adetunmise C. Dada
High Energy Physics (Phenomenology)
HEPToolBench 1.2: Testing How Reliably Language Models Can Drive Particle Physics Software
Aadarsh Singh and Sudhir K. Vempati
Scientists increasingly want to drive research software by natural-
language request, but fluent output helps only if it becomes a correct machine-readable artifact. We introduce HEPToolBench, a
benchmark of 28
collider-simulation tasks scored by deterministic, task-specific scorers, plus a three-task structured-debugging extension. We evaluate 42 deployments, from small locally served open-weight models to hosted frontier systems. The central experiment compares direct generation of native HEP-tool syntax with a schema-mediated interface where the model returns a typed representation that deterministic software serializes. Across five matched requests, the mean score rises from 0.418 to 0.902 and task passes from 21/210 to 159/210, with 41 of 42 deployments improving; eleven deployments, seven locally served open-weight models, go from 0/5 passes under native syntax to 5/5 under the structured interface. Values use the corrected v1.2.1 contract, in which the two native scorers that had enforced operational conventions absent from their own
prompts are rescored
prompt-faithfully cohort-wide. One asymmetry remains: native scorers score the recorded response verbatim and reject Markdown-fenced replies, whereas structured scorers recover JSON from such wrappers; no full-cohort rescoring under a single symmetric extraction rule has been done. An audit of archived responses from 17 locally served deployments shows this does not explain their gains: passes remain six to ten times more frequent under the structured interface when both sides use the same extraction rule. A task pass alone does not guarantee runtime or scientific viability. Within this scope, moving syntax generation into deterministic software can substantially improve reliability for both small local and frontier models.
Prompts, scorers, responses, and regeneration scripts are released for independent evaluation and extension.
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Mesoscale and Nanoscale Physics
Quantum Geometric Origin of Nonlinear Current Induced Orbital Magnetization
Xue-Jin Zhang, Yue-Xin Huang, Wei Du et al. (+5 more)
Electric generation of magnetization is a focus of condensed matter research, and has recently been advanced into the nonlinear regime. However, due to the nonlocal nature of orbital magnetism, how to properly formulate nonlinear current-induced orbital magnetization remains a fundamental challenge. Here, we develop the proper theory for this effect. This is based on the microscopic derivation of field-corrected orbital
magnetic moment of a Bloch electron, a critical missing piece in the present theory. We show that the
quantum geometric origin of this phenomenon lies in both the anomalous orbital polarizability and the Berry-connection polarizability, which often provide competing contributions. Combining our theory with first-principles calculations, we predict significant, experimentally accessible nonlinear orbital magnetization generated in strained
bilayer graphene, monolayer 1T' $\mathrm{MoS_2}$ and $\mathrm{MoTe_2}$. Remarkably, nonlinear orbital magnetization can dominate over its
spin counterpart in materials with topological band features, irrespective of the
spin-orbit coupling strength.
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All authors Xue-Jin Zhang, Yue-Xin Huang, Wei Du, Xiaolong Feng, Shen Lai, Cong Xiao, Qian Niu, Shengyuan A. Yang
Instrumentation and Methods for Astrophysics
The PLACID active coronagraphic imager instrument: commissioning status
Ruben Tandon, Lucas Marquis, Liurong Lin et al. (+9 more)
The world's first adaptive
stellar coronagraph, the Programmable
Liquid-
crystal Active Coronagraphic Imager for the 4-m DAG
telescope (PLACID) uses a spatial light modulator operating from H- to Ks-band to dynamically adjust the focal-plane phase mask entirely in software. Positioned between the TROIA XAO system and the DIRAC infrared detector, PLACID was installed on the Nasmyth platform of the Turkish 4-m DAG
telescope in 2025, followed by optical
alignment and successful preliminary acceptance tests with the calibration light source in early 2026. On-sky commissioning is expected, as soon as the TROIA XAO system will be operational. When on-sky, it will enable high-contrast imaging of
exoplanets, brown
dwarfs, disks, and binary systems, being able to easily deploy any desired phase pattern in the focal plane. Upcoming features include self-calibration of non-common path aberrations, coronagraphic nulling of binary-
stars, and coherent differential imaging. We present the preliminary acceptance procedures and internal
alignment results, discovery-space estimates, new binary
star features and observation tools, to be ready for first science by late 2026/early 2027.
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All authors Ruben Tandon, Lucas Marquis, Liurong Lin, Derya Öztürk Çetni, Axel Potier, Audrey Baur, Iljadin Manurung, Matthias Brändli, Martin Rieder, Daniele Piazza, Laurent Jolissaint, Jonas G. Kühn
Instrumentation and Methods for Astrophysics
Design and implementation of an SLM-driven coherent differential imaging scheme
L. Lin, L. Marquis, R. Tandon et al. (+1 more)
Direct imaging of
exoplanets from the ground remains fundamentally limited by fast-evolving post-adaptive optics (AO) residual wavefront errors, and by quasi-static speckles arising from non-common path aberrations (NCPAs) downstream of the AO wavefront sensor. To first order, both sources of contrast degradation remain coherent with the
stellar light, and recent studies have shown that coherent differential imaging (CDI) techniques can address their quasi-static and slowly evolving components. Recent laboratory demonstrations using focal plane phase diversity with an active LCoS spatial light modulator (SLM) have further established that local phase modulation can distinguish coherent speckles from incoherent astrophysical signals. Here we present a framework for the design and implementation of an SLM-based CDI integrator. Through simulations, we study the effects of varying the number of phase steps, modulation ring width,
planet separation, and
planet-to-
star contrast. The numerical results are further supported by an initial laboratory validation. In the future, with the emergence of ultra-low-noise fast near-infrared detectors such as avalanche photodiode and microwave kinetic inductance detector (MKID) arrays, time-domain focal-plane CDI detection schemes could potentially also be able to suppress rapidly varying post-AO residual wavefront errors.
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All authors L. Lin, L. Marquis, R. Tandon, J. Kühn