物理最新文献

{"title":"Weakly nonlinear creep of amorphous polymers near their glass transition: comparisons between models and experiment","authors":"Martin Roman-Faure,&nbsp;Zhaocheng Zhang,&nbsp;Catalin Picu,&nbsp;Antoine Chateauminois,&nbsp;François Lequeux","doi":"10.1140/epje/s10189-026-00646-z","DOIUrl":"10.1140/epje/s10189-026-00646-z","url":null,"abstract":"<p>The non-linear mechanics of amorphous polymers near the glass transition reveals a stress-induced acceleration of stress relaxation of nano-metric sub-units. Recent theoretical work predicts that the local acceleration within these nano-domains should scale as the exponential of the squared local stress, a behavior now supported by experiments. However, this local dynamics has some complex consequences on the macroscopic mechanical response, as dynamical heterogeneities generate complex stress and strain fields in polymers close to the glass transition. In this study we consider the nonlinear creep of an amorphous polymer near its glass transition and evaluate the relation between local and global acceleration and the emerging load-carrying structure, by comparing experimental data with predictions of three models of increasing complexity: a two-state (2S) model, a self-consistent (SC) model and a finite element (FEM) model. The experimentally observed trend of accelerated creep under increasing applied stress is reproduced by the SC and FEM models, while the 2S model overestimates stress localization. The macroscopic, homogenized acceleration is predicted to be close to the microscopic one, albeit with an apparent yield stress that depends on compliance. The FEM model evidences the development of a load-carrying substructure that occupies a small fraction of the total material volume driven by the interaction of sub-domains. This work shows that complexity and heterogeneity emerge due to nonlinear interactions and that their adequate representation is essential for predicting the macroscopic mechanical response of amorphous polymers near their glass transition.</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"49 10","pages":""},"PeriodicalIF":2.6,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149164001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ultrafast coherent excitation control and nanometer-scale imaging: a conceptual design integrating FEL interference modulation with electron probing","authors":"Jian Gao,&nbsp;Anzhou Yang,&nbsp;Qixuan Yuan,&nbsp;Xia Yang,&nbsp;Dongfang Zhang,&nbsp;Yinpeng Zhong","doi":"10.1140/epjd/s10053-026-01270-4","DOIUrl":"10.1140/epjd/s10053-026-01270-4","url":null,"abstract":"<p>This work proposes a system integration framework and conceptual design that synergizes Free-Electron Laser (FEL)-induced transient gratings with ultrafast electron beam probing to explore non-equilibrium dynamics. Leveraging the extreme ultraviolet (EUV) wavelength, high coherence, and element-selective resonant FEL excitation combined with broadband electron imaging of post-excitation dynamics of the Shenzhen Superconducting Soft X-ray Free-Electron Laser (S³FEL), we present an instrument coupling scheme governed by an adaptive grating phase-matching law to establish coherent transient gratings (<span>({Lambda}_{text{T}text{G}}approx 14-49 text{n}text{m})</span>). This setup is designed to access high-momentum (<span>(q)</span>) excitations that are kinematically inaccessible to conventional optical techniques, offering a prospective platform for exploring collective electronic orders—such as polarons and photo-ionized Charge Density Waves (CDWs)—at the nanometer scale. By targeting nanoscale spatial regimes (<span>(approx 20 nm)</span>), the scheme provides a promising framework for potential future studies on the transition from classical diffusion to phase-coherent transport and element-resolved proximal spin exchange. To detect these transient states under realistic constraints, the platform integrates a THz-driven compact electron gun operating consistently at a 1.5 keV baseline. Utilizing particle tracking and electron-optics simulations, we model the far-field non-coherent deflection mapping and real-space intensity modulation of a compressed 49 fs electron probe across a 10 <span>(upmu text{m})</span> field of view, successfully resolving the spatiotemporal mismatch and coherence budget limitations. These comprehensive simulations validate the technical feasibility of the proposed cooperative instrumentation path, providing a self-consistent theoretical foundation for future experimental realization dedicated to mapping many-body interactions across mesoscopic scales.</p>","PeriodicalId":789,"journal":{"name":"The European Physical Journal D","volume":"80 10","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149188992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mass spectra and electromagnetic characteristics of the (K^{(*)}bar{D}^{(*)}) and (K^{(*)}{D}^{(*)}) molecular tetraquarks from the coupled-channel dynamics","authors":"Jia-Ning Cui,&nbsp;Fu-Lai Wang","doi":"10.1140/epjc/s10052-026-16407-3","DOIUrl":"10.1140/epjc/s10052-026-16407-3","url":null,"abstract":"<div><p>Motivated by the observation of numerous charmed-strange hadrons lying close to the <span>(K^{(*)}bar{D}^{(*)})</span> and <span>(K^{(*)}D^{(*)})</span> thresholds, we systematically investigate their mass spectra and electromagnetic characteristics, explicitly incorporating the <i>S</i>-<i>D</i> wave mixing and coupled-channel effects. For the mass spectra, we employ the one-boson-exchange model and obtain several promising <span>(K^{(*)}bar{D}^{(*)})</span> and <span>(K^{(*)}D^{(*)})</span> molecular candidates awaiting future experimental confirmation. The coupled-channel dynamics is found to play an essential role: it not only enhances binding in existing channels but also generates new loosely bound states that are absent in the single-channel approximation. Regarding the electromagnetic characteristics, we discuss the M1 radiative decay widths and magnetic moments of these charmed-strange molecular tetraquarks based on our obtained mass spectra and spatial wave functions within the constituent quark model. Our results demonstrate that the electromagnetic observables serve as valuable discriminants for clarifying the nature of these hadronic molecules. We encourage experimental collaborations to focus on such predicted charmed-strange molecular tetraquark candidates, especially the genuinely exotic <span>(K^{(*)}bar{D}^{(*)})</span> states comprising four different flavors with valence quark content <span>(bar{c} bar{s} u d)</span>.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 10","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-16407-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149189423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simulation of subharmonic frequency lock-in and phase synchronization using Van der Pol equation","authors":"Nizar Abcha,&nbsp;Reine Matar,&nbsp;Iskander Abroug","doi":"10.1140/epje/s10189-026-00645-0","DOIUrl":"10.1140/epje/s10189-026-00645-0","url":null,"abstract":"<div><p>This study examines subharmonic frequency lock-in and phase synchronization of vortex shedding behind a partially immersed circular cylinder placed in a steady water current and subjected to harmonic surface waves. A forced Van der Pol wake-oscillator model was developed to describe the nonlinear coupling between the wake dynamics and external periodic forcing, with parameters validated against wave-flume experiments. Both numerical and experimental results reveal that synchronization occurs when the forcing frequency is approximately twice the natural shedding frequency, forming Arnold-tongue-shaped regions in the amplitude–frequency plane. At the edges of these regions, chaotic and intermittent behaviors emerge, highlighting the nonlinear nature of the wake–forcing interaction. The strong agreement between model predictions and laboratory observations confirms the relevance of the Van der Pol framework for predicting vortex-induced vibration in oscillatory environments and provides insight into the transition between unsynchronized and fully phase-locked regimes. In addition, a machine learning framework based on a multilayer perceptron (MLP) was implemented to classify synchronization states directly from the frequency–forcing parameter space. The MLP successfully reproduced the experimentally observed synchronization boundaries and achieved prediction accuracies exceeding 93% for experimental data and 98% for theoretical data, demonstrating its capability to identify complex nonlinear lock-in dynamics. These results highlight the potential of combining physics-based reduced-order models with data-driven approaches for improved prediction and analysis of flow synchronization phenomena.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><img></picture></div></div></figure></div></div>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"49 10","pages":""},"PeriodicalIF":2.6,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149164019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Charge-dependent scalarization of Einstein–Euler–Heisenberg black holes","authors":"Lina Zhang,&nbsp;Yun Soo Myung,&nbsp;De-Cheng Zou,&nbsp;Chao-Ming Zhang,&nbsp;Sheng-Yuan Li","doi":"10.1140/epjc/s10052-026-16436-y","DOIUrl":"10.1140/epjc/s10052-026-16436-y","url":null,"abstract":"<div><p>Charge-dependent scalarization of the Einstein–Euler–Heisenberg (EEH) black hole is carried out in the EEH-scalar theory by introducing an exponential scalar coupling with coupling constant <span>(alpha )</span> to the Maxwell and nonlinear electrodynamic terms. The bald black hole (EEHBH) is described by mass <i>M</i> and arbitrary magnetic charge <i>q</i> and has a single horizon when choosing the action parameter <span>(mu =0.3)</span>. Here, we find the critical onset charge <span>(q_c=r_+^2/sqrt{2mu })</span> with <span>(r_+(M,q_c))</span> the outer horizon radius from the resonance condition. The spontaneous scalarization (<span>(alpha ^+)</span>) of this black hole is available for charge <span>(0&lt;q&lt; q_c=1.115)</span> for <span>(M=1)</span> and <span>(mu =0.3)</span>, with positive <span>(alpha )</span>, whereas its new scalarization (<span>(alpha ^-)</span>) occurs for <span>(q&gt; q_c)</span> and negative <span>(alpha )</span>. The former case of <span>(q=0.5)</span> implies infinite branches of scalarized EEHBHs but its fundamental branch (<span>(n=0)</span>) is stable against the <span>(l=0)</span> modes considered here, while for <span>(q=2)</span> and <span>(q=20)</span>, one stable scalarized branch is found for each charge within the explored parameter ranges.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 10","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-16436-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149189424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correction: New constraints on cosmic-ray boosted sub-Gev dark matter via light mediators","authors":"Yang Yu,&nbsp;Guan-Sen Wang,&nbsp;Bo Zhang,&nbsp;Tian-Peng Tang,&nbsp;Bing-Yu Su,&nbsp;Lei Feng","doi":"10.1140/epjc/s10052-026-16447-9","DOIUrl":"10.1140/epjc/s10052-026-16447-9","url":null,"abstract":"","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 10","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-16447-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149189426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pion emission source shape in UrQMD Au + Au collisions at STAR energies","authors":"Mátyás Molnár,&nbsp;Dániel Kincses,&nbsp;Yan Huang,&nbsp;Máté Csanád","doi":"10.1140/epja/s10050-026-01970-w","DOIUrl":"10.1140/epja/s10050-026-01970-w","url":null,"abstract":"<div><p>Femtoscopic measurements of two-pion Bose–Einstein correlations have established that particle-emitting sources in heavy-ion collisions are well described by Lévy <span>(alpha )</span>-stable distributions, motivating systematic studies across a wide range of collision energies. In this work, we present a three-dimensional femtoscopic analysis of pion pairs in Au + Au collisions simulated with the UrQMD model for collision energies <span>(sqrt{s_{NN}}=3)</span>–<span>(27,textrm{GeV})</span>, taking the RHIC BES-II range of collider and fixed target experiment energies for reference. Using Lévy-type source parameterisations, we extract the Lévy index <span>(alpha )</span>, the three-dimensional radii <span>(R_textrm{out})</span>, <span>(R_textrm{side})</span>, <span>(R_textrm{long})</span>, and the pair multiplicity parameter <span>(lambda ^{*})</span> (related to the correlation strength <span>(lambda )</span>). We investigate their dependence on the transverse mass (<span>(m_T)</span>) and collision energy, along with derived quantities such as the radius difference <span>(R_{textrm{diff}}^2=R_{textrm{out}}^2-R_textrm{side}^2)</span> and the ratio <span>(R_textrm{out}/R_textrm{side})</span>. We find that <span>(R_textrm{out,side,long})</span> all decrease with increasing <span>(m_T)</span> and increase with collision energy, consistent with collective expansion, <span>(R_textrm{long})</span> showing the strongest and <span>(R_textrm{side})</span> the weakest energy dependence. The Lévy index <span>(alpha )</span> decreases with collision energy, with a larger <span>(m_T)</span>-dependence towards higher energies. The <span>(lambda ^{*})</span> parameter is consistent with a constant close to unity in the absence of pions from long-lived resonances. These results provide a baseline for future comparisons with experimental measurements from the STAR Collaboration, contributing to constraints on the QCD phase diagram.</p></div>","PeriodicalId":786,"journal":{"name":"The European Physical Journal A","volume":"62 10","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epja/s10050-026-01970-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149189001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Polylogarithmic structure of Bragg diffraction in finite-coherence lattices","authors":"Evangelos G. Filothodoros","doi":"10.1140/epjb/s10051-026-01279-z","DOIUrl":"10.1140/epjb/s10051-026-01279-z","url":null,"abstract":"<p>We develop a polylogarithmic structure for Bragg diffraction based on a weighted multi-plane interference model. Within this kind of construction, the scattering amplitude is expressed as a polylogarithmic generating function. By introducing extra contributions with power-law and the usual exponential decay, it takes the form <span>(F(q) = textrm{Li}_mleft( e^{i qd - epsilon }right) )</span>, where <span>(epsilon )</span> is a finite coherence length. In the infinite-coherence limit, Bragg enhancement is associated with the approach of the polylogarithmic argument to its boundary singular point <span>(z=1)</span>. This formulation provides a compact analytical framework for describing diffraction line shapes within a generalized correlation model in which peak positions, widths, and line shapes arise from a single analytic structure. Although we are able to recover the standard Bragg law for ideal crystals, the polylogarithm model captures deviations due to finite correlation length, disorder and non-uniform lattice coherence. We show that if Bragg peaks correspond to boundary singularities of the polylogarithm, a connection between diffraction theory and complex analysis arises. The proposed theoretical model may be particularly relevant for disordered or partially coherent materials, where conventional diffraction models often require additional phenomenological broadening assumptions.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"99 10","pages":""},"PeriodicalIF":1.9,"publicationDate":"2026-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149188893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Noise-aware derivative feedback of a harmonic oscillator under quantum-limited position measurement","authors":"Vedran Vujnović","doi":"10.1140/epjd/s10053-026-01271-3","DOIUrl":"10.1140/epjd/s10053-026-01271-3","url":null,"abstract":"<p>We study measurement-based feedback control of a damped harmonic oscillator, motivated by optomechanical and interferometric position measurements, in which the feedback force is synthesized directly from a displacement measurement. For a band-limited derivative (“dirty-derivative”) controller, the feedback loop simultaneously shapes the mechanical susceptibility and reinjects measurement noise back onto the oscillator, creating a nontrivial tradeoff between stabilization and noise amplification. We first present a compact classical formulation that isolates this tradeoff in the closed-loop displacement spectrum and identifies the controller parameters that determine resonance suppression versus noise-driven actuation. We then extend the same topology to a quantum-limited position detector, enforcing the imprecision–backaction constraint and introducing a finite measurement bandwidth that both regularizes high-frequency noise reinjection and adds phase lag in the feedback path. In the high-<i>Q</i> regime, we obtain a compact analytic design rule for the optimal feedback gain at fixed controller and measurement bandwidths and compare it directly with full-spectrum calculations. The comparison shows that a high mechanical quality factor alone does not guarantee quantitative agreement: the accuracy of the near-resonant approximation also depends strongly on the controller and measurement bandwidths. Because finite measurement bandwidth changes both the magnitude and phase of the feedback loop, the analysis separates the near-resonant damping contribution from imprecision-noise reinjection and shows that positive near-resonant feedback damping requires the product of the controller cutoff and measurement bandwidth to exceed the square of the mechanical resonance frequency. Finally, we present a dimensionless map of the gain-optimized high-<i>Q</i> occupation and compare its predictions with full-spectrum optimization. All analytical gains evaluated in this map satisfy the full closed-loop stability criterion for the stated parameters.</p>","PeriodicalId":789,"journal":{"name":"The European Physical Journal D","volume":"80 10","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149189355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Criterion for the existence of the G(3900) resonance","authors":"Yin Huang,&nbsp;Xurong Chen","doi":"10.1140/epjc/s10052-026-16432-2","DOIUrl":"10.1140/epjc/s10052-026-16432-2","url":null,"abstract":"<div><p>About 18 years ago, the BABAR and the Belle Collaborations reported evidence for a new <span>(cbar{c})</span> structure near <span>(3900~textrm{MeV})</span> in <span>(e^{+}e^{-} rightarrow Dbar{D})</span>, triggering debate over whether it represents a genuine hadronic state or arises from interference effects and the opening of the <span>(D^{*}bar{D})</span> threshold. The issue remained unsettled until 2024, when BESIII, with an enlarged <span>(e^{+}e^{-} rightarrow Dbar{D})</span> sample, confirmed the presence of the <i>G</i>(3900) structure, reviving discussion of its nature. Although it has been proposed as a <i>P</i>-wave <span>(Dbar{D}^{*})</span> molecular state, no consensus has emerged, and interference effects remain a plausible explanation. In this Letter, we show that analyzing the <span>(e^{+}e^{-}rightarrow Dbar{D})</span> cross section as a function of the transverse momentum of the final-state <i>D</i> meson reveals a prominent Jacobian peak. This feature cannot be generated by interference effects alone and thus provides direct evidence for the existence of <i>G</i>(3900). Moreover, the peak position is highly sensitive to the actual mass of <i>G</i>(3900), offering a precise determination method. The criterion illustrated by <i>G</i>(3900) can be extended to other hadronic systems, offering a powerful tool to identify genuine resonances.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 10","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-16432-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149132792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}