Publications

2026

• Rotating the Color Glass Condensate
  
  • Boussarie Renaud
  • Caucal Paul
  • Korcyl Piotr
  • Mehtar-Tani Yacine
  Physical Review Letters, American Physical Society, 2026, 137 (12), pp.121903. High-energy QCD evolution beyond leading order suffers from instabilities driven by large collinear logarithms. We present a framework, consistent with the standard high-energy operator product expansion (OPE), that restores perturbative stability order by order. The method involves a change of basis in the space of high-energy operators, which modifies both the evolution kernel and the coefficient functions while leaving physical observables invariant. Within this factorization scheme, we derive a next-to-leading-order renormalization-group equation whose numerical solution exhibits stable evolution up to large rapidities, thereby establishing a solid foundation for precision studies of gluon saturation at current and future colliders. (10.1103/k59p-5nb6)
  DOI : 10.1103/k59p-5nb6
• Extracting Essential Non-perturbative Information in Jet Invariant Mass via the Bayesian Analysis
  
  • Gao Zhan
  • Shi Yu
  • Xiao Bo-Wen
  • Zhang Han-Zhong
  Nucl.Phys.B, 2026, 1031, pp.117646. In this paper, we present a new three-dimensional non-perturbative (NP) function to account for and parameterize the NP contributions in the jet invariant mass spectrum, in addition to the conventional NP mass shift parametrization. By implementing Bayesian analysis on experimental data of the jet invariant mass from exclusive $W/Z+$jet events and inclusive jet events in $pp$ collisions at RHIC and LHC, where collisional energy increases by a factor of up to $65$ from RHIC to LHC, we ensure the analysis covers a wide range of data. For the first time, we simultaneously extract NP contributions from hadronization, initial soft-gluon radiation, and underlying events, based on two different NP prescriptions. We find that the contribution from initial soft-gluon radiation is negligible, and the hadronization effect dominates in the small-$R$ region, while underlying events provide the dominant contribution in the large-$R$ region. Moreover, when only hadronization effects are considered, our results successfully describe the jet mass data measured in $e^+e^-$ collisions, where only hadronization effects are expected to be present. Our work offers quantitative insights into understanding the soft hadronic contribution to jet substructure. (10.1016/j.nuclphysb.2026.117646)
  DOI : 10.1016/j.nuclphysb.2026.117646
• Bubble dynamics in a QCD-like phase diagram
  
  • Bea Yago
  • Giliberti Mauro
  • Mateos David
  • Sanchez-Garitaonandia Mikel
  • Serantes Alexandre
  • Zilhão Miguel
  Journal of High Energy Physics, Springer, 2026, 04, pp.013. A line of first-order phase transitions is conjectured in the phase diagram of Quantum Chromodynamics at non-zero baryon density. If this is the case, numerical simulations of neutron star mergers suggest that various regions of the stars may cross this line multiple times. This results in the nucleation of bubbles of the preferred phase, which subsequently expand and collide. The resulting gravitational wave spectrum is highly sensitively to the velocity of the bubble walls. We use holography to perform the first microscopic simulation of bubble dynamics in a theory that qualitatively mirrors the expected phase diagram of Quantum Chromodynamics. We determine the wall velocity in the metastable regions and we compare it to theoretical estimates. We discuss implications for gravitational wave production. (10.1007/JHEP04(2026)013)
  DOI : 10.1007/JHEP04(2026)013
• Exact solution and Luttinger liquid behavior of the quantum 1D hard rod model
  
  • Yu Shengjie
  • Zhu Zhaoxuan
  • Sanchez-Palencia Laurent
  Phys.Rev.A, 2026, 113, pp.033304. The quantum hard rod model, a one-dimensional extension of the Lieb-Liniger model, is exactly solved using an adapted Bethe ansatz. Our solution, benchmarked against path-integral quantum Monte Carlo calculations, reveals significant corrections to the excitation spectrum and thermodynamic properties, previously overlooked by the standard excluded-volume approach. We also show that the hard rod model exhibits Luttinger liquid behavior across a wide range of parameters, at zero and finite temperature, as unveiled by correlation functions. This work provides a comprehensive framework for understanding strongly correlated regimes in dilute 1D systems, with applications to quantum wires, spin chains, and ultracold atoms. (10.1103/8gzf-v52y)
  DOI : 10.1103/8gzf-v52y
• Multipole structure of the nucleon tensor form factors
  
  • Ghim Nam-Yong
  • Won Ho-Yeon
  • Kim June-Young
  • Kim Hyun-Chul
  Physical Review D, American Physical Society, 2026, 114 (3), pp.034016. We investigate the multipole structure of the nucleon tensor form factors within the chiral quark-soliton model based on the $1/N_c$ expansion. Extending the previous leading-order analysis~\cite{Ghim:2025gqo}, we include the rotational $1/N_c$ corrections. These corrections provide the leading nonvanishing contributions to the flavor components that are absent at leading order, thereby completing the flavor decomposition of the tensor multipole form factors at the present order. We numerically evaluate the isoscalar tensor charge, the isovector anomalous tensor magnetic moment, and the isoscalar tensor quadrupole moment, obtaining $g_T^{u+d}=0.81$, $κ_T^{u-d}=1.97$, and $E_T^{u+d}(0)=5.98$, respectively. The isoscalar tensor charge and quadrupole moment are mainly governed by the valence-quark contribution, whereas the isovector anomalous tensor magnetic moment receives a sizable Dirac-sea contribution. We also examine the momentum-transfer dependence of the corresponding form factors. They decrease monotonically with increasing $-t$. In particular, the isovector anomalous tensor magnetic form factor shows a pronounced falloff in the small-$|t|$ region, reflecting the importance of the Dirac sea in the tensor dipole structure. (10.1103/wtdr-92yh)
  DOI : 10.1103/wtdr-92yh
• Analysis of ATLAS pp elastic measurements at $\sqrt{s}$=13 TeV and comparison with TOTEM measurements
  
  • Ferreira E
  • Kodama T
  • Kohara A.K
  European Physical Journal C: Particles and Fields, Springer Verlag (Germany), 2026, 86 (5), pp.444. A comparative description is made of the measurements at LHC of pp elastic scattering at 13 TeV by the ATLAS and TOTEM Collaborations. In the total and differential cross sections we show that the differences are justified through single numerical factor. It seems that there is no fundamental physical difference, but only a difference of normalization between the two experiments. We study the real and imaginary amplitudes disentangled with the KFK (Kohara-Ferreira-Kodama) model and show that the properties are similar in qualitative aspects for both experiments. The real and imaginary parts have different slopes at the origin and present zeros, with distributions that are common to several models, with three zeros in the real part and one zero in the imaginary amplitude. A zero in the real part, known as Martin's zero, influences the determination of the $ρ$ parameter. (10.1140/epjc/s10052-026-15726-9)
  DOI : 10.1140/epjc/s10052-026-15726-9
• Entanglement entropy, Monte Carlo event generators, and soft gluons DIScovery
  
  • Hentschinski Martin
  • Jung Hannes
  • Kutak Krzysztof
  Physical Review D, American Physical Society, 2026, 113 (5), pp.054024. We study entropy production in Deep Inelastic Scattering using Monte Carlo simulations. We show that the dominant contribution to entropy is due to soft gluons. This contribution is usually neglected in standard Monte Carlo approaches, since it does not affect hadronic spectra. However, it is relevant for entropy and multiplicity distributions, as we demonstrate with explicit calculations. We further show that, as one lowers the cutoff - i.e. includes soft gluons - thereby making the Monte Carlo parton distributions closer to inclusive PDFs, the resulting entropy is very close to that measured by the H1 collaboration, without the need to account for hadronization effects. This provides further evidence that the bulk of the measured entropy originates from initial-state effects. (10.1103/q8s9-kd9s)
  DOI : 10.1103/q8s9-kd9s
• Topological markers for a one-dimensional fermionic chain coupled to a single-mode cavity
  
  • Ritz-Zwilling Anna
  • Dmytruk Olesia
  Phys.Rev.B, 2026, 114, pp.165423. We study a Su-Schrieffer-Heeger chain coupled to a single mode photonic cavity. Considering an off-resonant regime we use the high-frequency expansion in order to obtain an effective fermionic Hamiltonian with cavity-mediated interactions. We characterize the effects of the cavity on topology in a finite size chain by studying three different markers adapted for interacting systems: correlation functions between edges in a chain with open boundary conditions, and a winding number based on the single-particle Green's function and bulk electric polarization via the many-body formula by Resta for a chain with periodic boundary conditions. There is excellent agreement between the winding number and polarization approaches to compute the phase diagram, with the presence of the edge states being confirmed through the calculations of the two-point correlation function. Our approach provides an alternative perspective on cavity-modified topological phases through a study of an effective interacting electronic Hamiltonian and complements methods that treat the full light-matter Hamiltonian directly. (10.1103/n492-rvhb)
  DOI : 10.1103/n492-rvhb
• Quantum vorticity: a not so effective field theory
  
  • Cuomo Gabriel
  • Eustachon Fanny
  • Firat Eren
  • Henning Brian
  • Rattazzi Riccardo
  SciPost Physics, SciPost Foundation, 2026, 20 (1), pp.018. We provide a comprehensive picture for the formulation of the perfect fluid in the modern effective field theory formalism at both the classical and quantum level. Due to the necessity of decomposing the hydrodynamical variables $(\rho, p, u^\mu)$ into other internal degrees of freedom, the procedure is inherently not unique. We discuss and compare the different inequivalent formulations. These theories possess a peculiarity: the presence of an infinite dimensional symmetry implying a vanishing dispersion relation $\omega = 0$ for the transverse modes. This sets the stage for UV-IR mixing in the quantum theory, which we study in the different formulations focussing on the incompressible limit. We observe that the dispersion relation gets modified by quantum effects to become $\omega \propto \mathbf{k}^2$, where the fundamental excitations can be viewed as vortex-anti-vortex pairs. The spectrum exhibits infinitely many types of degenerate quanta. The unusual sensitivity to UV quantum fluctuations renders the implementation of the defining infinite symmetry somewhat subtle. However we present a lattice regularization that preserves a deformed version of such symmetry. (10.21468/SciPostPhys.20.1.018)
  DOI : 10.21468/SciPostPhys.20.1.018
• Perturbative results for the matrix elements of the vector current and the role of different infrared regulators
  
  • Alvaro Alessio Carmelo
  • Castelli Ignacio
  • Lorcé Cédric
  • Metz Andreas
  • Pasquini Barbara
  • Rodini Simone
  Physics Letters B, Elsevier, 2026, 878, pp.140501. We investigate the twist-2 unpolarized generalized parton distributions (GPDs) of quarks for an on-shell gluon target in quantum chromodynamics. These GPDs parametrize the leading-twist matrix elements of the nonlocal light-like flavor-singlet vector current. We compute them at one-loop accuracy in perturbation theory using a quark mass and dimensional regularization as infrared regulators. In particular, we discuss the limit of vanishing momentum transfer. The present work extends our previous related study on the axial current. (10.1016/j.physletb.2026.140501)
  DOI : 10.1016/j.physletb.2026.140501
• Mesons, baryons and the confinement/deconfinement transition
  
  • Mari Surkau V. Tomas
  • Reinosa Urko
  Physics Letters B, Elsevier, 2026, 874, pp.140288. We relate the Polyakov and anti-Polyakov loops, which determine how energetically costly it is to bring an external static quark or antiquark probe into a bath of quarks and gluons, to the ability of that same medium to provide the conditions for the formation of meson-like or baryon-like configurations that would screen the probes. (10.1016/j.physletb.2026.140288)
  DOI : 10.1016/j.physletb.2026.140288
• Bipartite Current Fluctuations in Quantum Wires through Charge Fractionalization
  
  • Korolev Magali
  • Le Hur Karyn
  Physical Review B, American Physical Society, 2026, 113 (11), pp.115105. Quantum information measures of many-body systems often imply a measure with multi- or two regions such as bipartite charge fluctuations within the ground state revealing the logarithmic profile of the entanglement entropy in a quantum wire. Here, we introduce a new method from the bipartite current fluctuations and the divergence theorem. They reveal the fractional charges related to ground-state energetics and the proximity to Mott physics in the same ballistic quantum wires. This also encodes the behavior of the electron Green's function in space. With metallic gates on both sides of an interface to implement the protocol introducing the two macroscopic domains, bipartite current fluctuations can reveal an additional localized bound state associated to the topological Jackiw-Rebbi model, coexisting with the fractional charges. Through the Density Matrix Renormalization Group (DMRG) algorithm we introduce a quantum spin chain analogue. (10.1103/j2nl-ppfx)
  DOI : 10.1103/j2nl-ppfx
• Topological Signatures of Magnetic Phase Transitions with Majorana Fermions through Local Observables and Quantum Information
  
  • Hur Karyn Le
  • Yang Fan
  • Korolev Magali
  Physical Review B, American Physical Society, 2026, 113 (12), pp.L121106. The one-dimensional (1D) $J_1-J_2$ quantum spin model can be viewed as a strong-coupling analogue of the Schrieffer-Su-Heeger model with two inequivalent alternating Ising couplings along the wire, associated to the physics of resonating valence bonds. Similar to the quantum Ising model, which differently presents a long-range Neel ordered phase, this model also maps onto a p-wave superconducting wire which shows a topological phase transition with the emergence of low-energy Majorana fermions. We show how signatures of the topological phase transition for the p-wave superconducting wire, i.e. a half Skyrmion, are revealed through local (short-range) spin observables and their derivatives related to the capacitance of the pairing fermion model. Then, we present an edge correspondence through the edge spin susceptibility in the $J_1-J_2$ model revealing that the topological phase transition is a metal of Majorana fermions. We justify that the spin magnetization at an edge at very small transverse magnetic field is a good marker of the topological invariant. We identify a correspondence between the quantum information of resonating valence bonds and the charge fluctuations in a p-wave superconductor through our method ``the bipartite fluctuations''. This $J_1-J_2$ system may be realized in materials and engineered in quantum circuits, optical lattices. (10.1103/557d-dvl7)
  DOI : 10.1103/557d-dvl7
• Tests of restricted Quantum Focusing and a new CFT bound
  
  • Franken Victor
  • Kaya Sami
  • Rondeau François
  • Shahbazi-Moghaddam Arvin
  • Tran Patrick
  JHEP, 2026, 05, pp.111. The restricted quantum focusing conjecture (rQFC) plays a central role in an axiomatic formulation of semiclassical gravity. Since much hinges on its validity, it is imperative to subject the rQFC to rigorous tests in novel settings. Here we do so in two independent directions. First, we prove rQFC in a class of spacetime dimension $d=2$ toy models, JT gravity coupled to a QFT. We also construct explicit counter-examples to the original and stronger Quantum Focusing Conjecture in a regime where matter quantum effects are comparable to the total dilaton value. Second, for $d>2$, we derive from the rQFC a constraint stronger than the Quantum Null Energy Condition (QNEC). In a broad class of states, this bound forbids the QNEC from saturating faster than $O(\mathcal{A})$ as the transverse area $\mathcal{A}$ of a certain null deformation shrinks to zero. We speculate about a universal strengthened QNEC holding across all QFT states. (10.1007/JHEP05(2026)111)
  DOI : 10.1007/JHEP05(2026)111
• SU($N_c$) confinement and color $N_c$-ality
  
  • Mari Surkau V. Tomas
  • Reinosa Urko
  Physical Review D, American Physical Society, 2026, 113 (9), pp.094036. In a recent work, we have argued that the net quark number gained by a bath of quarks and gluons upon bringing an external static quark probe, while being equal to $1$ in the high temperature, deconfined phase, is equal to $0$ or $3$ in the low temperature, confined phase, depending on the value of the quark chemical potential. This establishes a clear-cut connection between the confinement of a medium as probed by order parameters such as the Polyakov loop, and the ability of that same medium to screen the quark probe into states with the same net quark content as mesons or baryons. In this work, we extend these findings to the SU($N_c$) color group, consider color probes in various (fundamental and non-fundamental) representations, and conjecture a rationale of how these results could be recovered from a purely thermodynamic argument that shortcuts the use of the Euclidean functional framework, while emphasizing the role of color $N_c$-ality as a proxy for center symmetry within the Minkowskian framework. (10.1103/98n6-tg1d)
  DOI : 10.1103/98n6-tg1d
• Transverse energy-momentum tensor distributions in polarized nucleons
  
  • Won Ho-Yeon
  • Lorcé Cédric
  Physical Review D, American Physical Society, 2026, 114 (1), pp.014012. We complete our study of the relativistic spatial distributions of the energy-momentum tensor inside polarized nucleons within the quantum phase-space formalism. In the present work, we focus on the components of the energy-momentum tensor involving at least one transverse index. We also explore the multipole structure of the transverse distributions in a moving nucleon. In the infinite-momentum frame, we show that the formalism reproduces the standard light-front distributions, including those with a ``bad'' component, and explains the origin of their structure. (10.1103/l7qb-49nz)
  DOI : 10.1103/l7qb-49nz
• Finite-time transition to intermittency for a stochastic heat equation driven by the square of a Gaussian field
  
  • Mounaix Philippe
  Journal of Physics A: Mathematical and Theoretical, IOP Publishing, 2026, 59 (37), pp.375204. In this paper, we study the spatial behavior of the solution ψ ( x , t ) to the stochastic heat equation ∂ t ψ ( x , t ) − 1 2 ∂ x 2 2 ψ ( x , t ) = g S ( x , t ) 2 ψ ( x , t ) , with 0 ⩽ t ⩽ T , x ∈ R , and ψ ( x , 0 ) = 1 . Here, g > 0 is a coupling constant and S ( x , t ) is a stationary, homogeneous, and ergodic Gaussian field. Focusing on E ( x , g ) ≡ ψ ( x , T ) at a finite time T > 0 , we identify the critical coupling g c ( T ) above which the average of E ( 0 , g ) diverges. We show that in the subcritical regime g < g c ( T ) , E ( x , g ) is spatially ergodic, with no intermittency, while in the supercritical regime g > g c ( T ) it becomes spatially intermittent and loses ergodicity. Our results differ from the extensively studied case where S ( x , t ) 2 is replaced by S ( x , t ) , in which intermittency appears only asymptotically as T → + ∞ , with no finite-time intermittency. (10.1088/1751-8121/aea45e)
  DOI : 10.1088/1751-8121/aea45e
• Bubbling wormholes and matrix models
  
  • Betzios Panos
  • Lee Ji Hoon
  • Papadoulaki Olga
  • Zhou Yanjun
  Journal of High Energy Physics, Springer, 2026, 06, pp.224. The thermofield double state entangles two copies of a CFT via a sum over energy eigenstates and is dual to the two-sided eternal black hole. We explore an analogous construction using sums over gauge group representations of half-BPS Wilson loops in multiple copies of $U(N)$$\mathcal{N}=4$ super Yang-Mills. These sums act as delta function-like operators that correlate the eigenvalues of the corresponding half-BPS matrix models. We suggest that the holographic duals are ''bubbling wormhole'' geometries: multi-covers of AdS$_5$$\times S^5$ whose conformal boundary consists of multiple four-spheres intersecting on a common circle. We analyze the matrix model free energy, discuss its bulk interpretation, and study probe loops in these backgrounds. (10.1007/JHEP06(2026)224)
  DOI : 10.1007/JHEP06(2026)224
• On the $(\text{Fib} \boxtimes \text{Fib}) \rtimes S_2$ fusion category
  
  • Ferragatta Maddalena
  • van Rees Balt C
  Journal of High Energy Physics, Springer, 2026, 06, pp.174. There might exist non-rational Virasoro CFTs in two dimensions with a $(\text{Fib} \boxtimes \text{Fib}) \rtimes S_2$ categorical symmetry. We calculate the necessary ingredients for a modular conformal bootstrap analysis of these theories. After reviewing the basics of fusion categories, we present the irreducible representations, the lasso maps that intertwine between different Hilbert spaces, and finally the 22-by-22 modular S matrix. We highlight the peculiarities introduced by the non-invertible nature of the symmetry. This paper is written in a pedagogical manner and can therefore serve as an accessible entry point into the literature. (10.1007/JHEP06(2026)174)
  DOI : 10.1007/JHEP06(2026)174
• Non-eikonal corrections to dijet production in DIS
  
  • Armesto Néstor
  • Domínguez Fabio
  • Romero Adrián
  JHEP, 2026, 09, pp.083. We compute non-eikonal corrections to dijet production in deep inelastic scattering off a nucleus. Such corrections are expected to be quantitatively important at the energies of the future Electron Ion Collider. We focus on those corrections stemming solely from the finite longitudinal size of the nucleus. For both longitudinally and transversely polarized photons, we provide general, all-order expressions in terms of two-dimensional path integrals. To proceed further, we use the harmonic oscillator approximation for the target averages of Wilson lines. We then expand the general expressions order by order beyond the shockwave limit which provides the eikonal results, up to next-to-next-to-eikonal accuracy. We observe that next-to-eikonal corrections to this observable vanish for the mentioned approximation for target averages, as previously found for single gluon production in proton-nucleus collisions. Finally, we calculate the back-to-back of correlation limit of our expressions. (10.1007/JHEP09(2026)083)
  DOI : 10.1007/JHEP09(2026)083
• Time-dependent Neural Galerkin Method for Quantum Dynamics
  
  • Sinibaldi Alessandro
  • Hendry Douglas
  • Vicentini Filippo
  • Carleo Giuseppe
  Physical Review Letters, American Physical Society, 2026, 136 (12), pp.120402. We introduce a classical computational method for quantum dynamics that relies on a global-in-time variational principle. Unlike conventional time-stepping approaches, our scheme computes the entire state trajectory over a finite time window by minimizing a loss function that enforces the Schrödinger's equation. The variational state is parametrized with a Galerkin-inspired ansatz based on a time-dependent linear combination of time-independent Neural Quantum States. This structure is particularly well-suited for exploring long-time dynamics and enables bounding the error with the exact evolution via the global loss function. We showcase the method by simulating global quantum quenches in the paradigmatic Transverse-Field Ising model in both 1D and 2D, uncovering signatures of ergodicity breaking and absence of thermalization in two dimensions. Overall, our method is competitive compared to state-of-the-art time-dependent variational approaches, while unlocking previously inaccessible dynamical regimes of strongly interacting quantum systems. (10.1103/kqvx-dl54)
  DOI : 10.1103/kqvx-dl54
• Uncovering thermodynamic origin of counterflow and coflow instabilities in miscible binary superfluids
  
  • An Yuping
  • Gouteraux Blaise
  • Li Li
  Physical Review A, American Physical Society, 2026, 113 (1), pp.013305. In this paper, we explore instabilities in binary superfluids with a nonvanishing relative superflow, particularly focusing on counterflow and coflow instabilities. We extend recent results on the thermodynamic origin of finite superflow instabilities in single-component superfluids to binary systems and derive a criterion for the onset of instability through a hydrodynamic analysis. To verify this result, we utilize both the Gross-Pitaevskii equation (GPE) for weakly interacting Bose-Einstein condensates (BEC) and a holographic binary superfluid model, which naturally incorporates strong coupling, finite temperature, and dissipation. We find that the counterflow and coflow instabilities in binary superfluids are all essentially thermodynamic. Except the one due to order competing via global thermodynamic instability, the others are caused by an eigenvalue of the free energy Hessian diverging and changing sign. We also observe that the critical velocities of these instabilities follow a general scaling law related to the interaction strength between superfluid components. The nonlinear stages of the instabilities are also studied by full time evolution, where vortex dynamics is found to play a significant role, resulting in the reduction of superfluid velocity back to a stable phase. (10.1103/g954-ddt7)
  DOI : 10.1103/g954-ddt7
• Hyperbolic form factors for Yukawa interactions, and applications to the Earth
  
  • Fayet Pierre
  European Physical Journal C: Particles and Fields, Springer Verlag (Germany), 2026, 86 (9), pp.1125. We define the hyperbolic form factor of a density distribution as its bilateral Laplace transform, related by duality or analytic continuation to its form factor. For a sphere it is given by $Φ(x = kR) =\langle \cosh \vec k.\vec r\rangle=\langle\sinh kr /kr\rangle $, expanded as $\sum \frac{x^{2n}}{(2n+1)!} \frac{\langle r^{2n}\rangle}{R^{2n}} $, and similarly for the form factor $ \langle \sin kr/kr\rangle$. It is also obtained from the bilateral Laplace transform of $2πr\,ρ(|r|)$, and enters in the determination of the outside Yukawa potential induced by a new charge for a mediator of mass $m=k=1/λ$. $Φ(x)$ may be expressed as $\frac{3}{x^3}\,(x \cosh x - \sinh x)\ \barρ(x)/ρ_0$, where $\barρ(x)$ is an effective density decreasing, for $dρ/dr<0$, from the average $ρ_0$ at small $x$, down to $ρ(R)$. An inversion formula allows one to recover $ρ(r)$ from an analytic continuation of $Φ(x)$, as $ρ(r) =ρ_0\,(2R/3πr)\intΦ(ix) \sin (x\frac{r}{R})\,x\,dx$. $Φ(x)$ for the Earth is essential to determine limits on a new force, as tested by MICROSCOPE, depending on the density distribution within the Earth. Quite remarkably, much simplified density profiles, such as $ρ= ρ_0\ 2R/3r $ or $ρ= ρ_0\, (\frac54-\frac{r}{R}+ \frac{R}{3r})$, provide analytic expressions of $Φ(x)$ and $\barρ(x)$ giving almost the same values as in a 5-shell model. $\,Φ(x)=(\sinh\frac{x}{2}/\frac{x}{2})^2$ is valid to within $\simeq 1\,\%$ up to $x=4$. $\,Φ(x)= [7x^2\cosh x-24\cosh x+9x\sinh x -4x^2+24]/(4x^4)$ is valid to within 1 % for $λ> $ 100 km (or $m< 2\times 10^{-12}$ eV/$c^2$). For $m=10^{-12}$ eV/$c^2$ the coupling limits are increased by 34 as compared to a massless mediator, to $|g_{B-L}|< 3.6 \times 10^{-24} $ and $|g_B|<2.6\times 10^{-23}$ for a spin-1 mediator, with slightly different limits in the spin-0 case. (10.1140/epjc/s10052-026-15933-4)
  DOI : 10.1140/epjc/s10052-026-15933-4
• Polaron-Driven Switching of Octupolar Order in Doped 5d² Double Perovskite
  
  • Fiore Mosca Dario
  • Celiberti Lorenzo
  • Pourovskii Leonid
  • Franchini Cesare
  Physical Review Letters, American Physical Society, 2026, 137 (4), pp.046504. We investigate how doping-induced small polarons impact the low-temperature multipolar orders of the 5d² double perovskite Ba₂CaOsO₆. By computing intersite exchange interactions between 5d¹ localized hole polarons and 5d² magnetic ions from first principles, we demonstrate the reversal of the dominant octupolar exchange from ferromagnetic to antiferromagnetic. Solving the corresponding effective Hamiltonian, we find this reversal to account for the progressive suppression of the ferro-octupolar order and the reduction of the ordering temperature upon Na doping. These findings clarify previously ambiguous experimental observations and demonstrate that charge doping in the form of small polarons offers a viable route to tuning intersite exchange interactions in spin-orbit-entangled materials, enabling the emergence of novel quantum orders. (10.1103/r8v5-h8bq)
  DOI : 10.1103/r8v5-h8bq
• A strong-weak duality for the 1d long-range Ising model
  
  • Benedetti Dario
  • Lauria Edoardo
  • Mazac Dalimil
  • van Vliet Philine
  SciPost Physics, SciPost Foundation, 2026, 20 (2), pp.029. We investigate the one-dimensional Ising model with long-range interactions decaying as $1/r^{1+s}$. In the critical regime, for $1/2 \leq s \leq 1$, this system realizes a family of nontrivial one-dimensional conformal field theories (CFTs), whose data vary continuously with $s$. For $s>1$ the model has instead no phase transition at finite temperature, as in the short-range case. In the standard field-theoretic description, involving a generalized free field with quartic interactions, the critical model is weakly coupled near $s=1/2$ but strongly coupled in the vicinity of the short-range crossover at $s=1$. We introduce a dual formulation that becomes weakly coupled as $s \to 1$. Precisely at $s=1$, the dual description becomes an exactly solvable conformal boundary condition of the two-dimensional free scalar. We present a detailed study of the dual model and demonstrate its effectiveness by computing perturbatively the CFT data near $s=1$, up to next-to-next-to-leading order in $1-s$, by two independent approaches: (i) standard renormalization of our dual field-theoretic description and (ii) the analytic conformal bootstrap. The two methods yield complete agreement. (10.21468/SciPostPhys.20.2.029)
  DOI : 10.21468/SciPostPhys.20.2.029