物理最新文献

{"title":"How oscillations in SIRS epidemic models are affected by the distribution of immunity times","authors":"Daniel Henrik Nevermann,&nbsp;Claudius Gros","doi":"10.1140/epjb/s10051-024-00858-2","DOIUrl":"10.1140/epjb/s10051-024-00858-2","url":null,"abstract":"<div><p>Models for resident infectious diseases, like the SIRS model, may settle into an endemic state with constant numbers of susceptible (<i>S</i>), infected (<i>I</i>) and recovered (<i>R</i>) individuals, where recovered individuals attain a temporary immunity to reinfection. For many infectious pathogens, infection dynamics may also show periodic outbreaks corresponding to a limit cycle in phase space. One way to reproduce oscillations in SIRS models is to include a non-exponential dwell-time distribution in the recovered state. Here, we study a SIRS model with a step-function-like kernel for the immunity time, mapping out the model’s full phase diagram. Using the kernel series framework, we are able to identify the onset of periodic outbreaks when successively broadening the step-width. We further investigate the shape of the outbreaks, finding that broader steps cause more sinusoidal oscillations while more uniform immunity time distributions are related to sharper outbreaks occurring after extended periods of low infection activity. Our main results concern recovery distributions characterized by a single dominant timescale. We also consider recovery distributions with two timescales, which may be observed when two or more distinct recovery processes co-exist. Surprisingly, two qualitatively different limit cycles are found to be stable in this case, with only one of the two limit cycles emerging via a standard supercritical Hopf bifurcation.</p></div>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjb/s10051-024-00858-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"The sharp lower bound of tricyclic graphs with respect to the ISI index: applications in octane isomers and benzenoid hydrocarbons","authors":"Qun Zhang,&nbsp;Shahid Zaman,&nbsp;Asad Ullah,&nbsp;Parvez Ali,&nbsp;Emad E. Mahmoud","doi":"10.1140/epje/s10189-025-00474-7","DOIUrl":"10.1140/epje/s10189-025-00474-7","url":null,"abstract":"<p>The inverse sum indeg index of a given graph <i>G</i> is symbolized with <i>ISI</i> and defined by sum of the weights <span>(frac{d_u d_v}{d_u + d_v})</span> entire links <span>(uvin G)</span>. We denote <span>(d_u)</span> (resp. <span>(d_v)</span>) the degree of a vertex <i>u</i> (resp. <i>v</i>) of <i>G</i>. In this paper, we obtained the sharp lower bound of tricyclic graphs with respect to the ISI index of order <span>(ngeqslant 6)</span> with size <span>(n + 2)</span>. By using atoms as vertices and chemical bonds as edges, graph theory permits the representation of molecular structures as mathematical entities called graphs. Based on the above concept, we formulated the <i>ISI</i> index of octane isomers (OI) and benzenoid hydrocarbons (BH) and compared the values of <i>ISI</i> index with various degree-based TI’s via their correlations and chemical properties. The structural analysis of octane isomers is an important application of this research, as the ISI index delivers insights into stability designs across various isomeric forms.</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"48 2","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143108285","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":"Susy at the FPF","authors":"Luis A. Anchordoqui,&nbsp;Ignatios Antoniadis,&nbsp;Karim Benakli,&nbsp;Jules Cunat,&nbsp;Dieter Lüst","doi":"10.1140/epjc/s10052-025-13839-1","DOIUrl":"10.1140/epjc/s10052-025-13839-1","url":null,"abstract":"<div><p>Experimental searches for supersymmetry (SUSY) are entering a new era. The failure to observe signals of sparticle production at the large hadron collider (LHC) has eroded the central motivation for SUSY breaking at the weak scale. However, String Theory requires SUSY at the fundamental scale <span>(M_s)</span> and hence SUSY could be broken at some high scale below <span>(M_s)</span>. Actually, if this were the case, the lack of experimental evidence for low-energy SUSY could have been anticipated, because most stringy models with high-scale SUSY breaking predict that sparticles would start popping up above about 10 TeV, well beyond the reach of current LHC experiments. We show that using next generation LHC experiments currently envisioned for the Forward Physics Facility (FPF) we could search for signals of neutrino-modulino oscillations to probe models with string scale in the grand unification region and SUSY breaking driven by sequestered gravity in gauge mediation. This is possible because of the unprecedented flux of neutrinos to be produced as secondary products in LHC collisions during the high-luminosity era and the capability of FPF experiments to detect and identify their flavors.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 2","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-13839-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143108213","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":"Zee model in a modular (A_4) symmetry","authors":"Takaaki Nomura,&nbsp;Hiroshi Okada,&nbsp;Yong-hui Qi","doi":"10.1140/epjc/s10052-025-13864-0","DOIUrl":"10.1140/epjc/s10052-025-13864-0","url":null,"abstract":"<div><p>We study a Zee model applying a modular <span>(A_4)</span> symmetry in supersymmetry framework, where we construct our lepton model as minimum modular weight as possible. We show our predictions on phases and neutrino masses through numerical analysis. We find a model that can fit in both normal and inverted hierarchy cases of neutrino mass. The predictions of neutrino observables are shown where we obtain more constrained allowed region in the inverted hierarchy case.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 2","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-13864-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143108217","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":"Synthesis and characterization of Fe-doped CdO nanoparticles via a coprecipitation method: application as a promising photodetector","authors":"S. Sebastian,&nbsp;P. Diana,&nbsp;V. Ganesh,&nbsp;D. Nagaraju,&nbsp;P. V. Raja Shekar","doi":"10.1007/s00339-025-08270-y","DOIUrl":"10.1007/s00339-025-08270-y","url":null,"abstract":"<div><p>In this study, CdO:Fe (2 wt%) samples were synthesized via chemical coprecipitation, utilizing cadmium nitrate and iron nitrate as precursors at different calcination temperatures (600°C, 700°C, and 800°C). The resulting materials were comprehensively characterized to determine their physicochemical properties and photoconductivity characteristics, with a focus on their structural, morphological, optical, magnetic, and electrical attributes. X-ray diffraction (XRD) analysis confirmed a pure cubic phase in all the CdO:Fe samples. Field emission scanning electron microscopy (FESEM) revealed that the synthesized samples exhibited a spherical, interconnected grain morphology. Energy-dispersive X-ray (EDX) micrographs confirmed the presence of Cd, O, and Fe. The Kubelka–Munk method was used to calculate the optical energy bandgap of the synthesized samples. Magnetization-field curves revealed ferromagnetic behavior in all the samples, with the maximum coercivity observed in the sample annealed at 600 °C. The CdO:Fe sample annealed at 800°C demonstrated the highest performance under light, with a maximum responsivity of 41.2 × 10^–1 A/W, an external quantum efficiency of 1329%, and a detectivity of 39 × 10¹⁰ Jones.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 3","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diagnosing emergent isotropy in anisotropic holographic systems using quantum information measures","authors":"Chong-Ye Chen,&nbsp;Mu-Jing Li,&nbsp;Zhe Yang,&nbsp;Da-Ming Jin,&nbsp;Peng Liu","doi":"10.1140/epjc/s10052-025-13797-8","DOIUrl":"10.1140/epjc/s10052-025-13797-8","url":null,"abstract":"<div><p>This study presents a comprehensive investigation of anisotropy in a holographic p-wave superconductor model, revealing novel insights into the behavior of quantum information in strongly coupled systems. Through rigorous semi-analytical methods, we uncover the existence of an isotropic point emerging at a critical temperature <span>(T_{II},)</span> marking a significant transition in the system’s anisotropic properties. We offer a systematic analysis of the mechanisms driving anisotropy and isotropy transitions, finding that this emergent isotropy point is unique to the p-wave model and absent in other anisotropic systems like anisotropic axion models with metal-insulator transitions. We propose that the explicit dependence of the vector field components in anisotropy is the key driver of the emergent isotropy. Our analysis of holographic entanglement entropy (HEE), entanglement wedge cross-section (EWCS), and butterfly velocity demonstrates their distinct sensitivities to bulk anisotropy. Among them, EWCS and butterfly velocity stand out as superior probes for detecting the isotropic point. Our findings provide a novel perspective on the interplay between unique emergent isotropic point and quantum information measures in strongly correlated systems.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 2","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-13797-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143108212","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":"Production of double strange hypernuclei and exotic nuclei in central Au+Au collisions at (sqrt{s_{NN}}) = 3 GeV","authors":"N. Buyukcizmeci,&nbsp;T. Reichert,&nbsp;A. S. Botvina,&nbsp;M. Bleicher","doi":"10.1140/epja/s10050-025-01489-6","DOIUrl":"10.1140/epja/s10050-025-01489-6","url":null,"abstract":"<div><p>We extend the theoretical approach which includes the dynamical and statistical stages for the description of the nucleosynthesis in central collisions of relativistic ions. Previously, this approach was successfully applied to describe experimental data on both normal nuclei and single strange hypernuclei production in the GSI and RHIC-BES energy range. We predict the multiplicities of double strange hypernuclei up to <span>(^4_{varLambda varLambda })</span>H and further intermediate mass nuclei up to <span>(^8)</span>Be for Au+Au central collisions at <span>(sqrt{s_{NN}})</span> = 3 GeV, recently explored by the STAR experiments. These nuclei can be identified by the measurement of the correlated particles coming after their decay. Such observations are a crucial test for the nucleosynthesis mechanism.</p></div>","PeriodicalId":786,"journal":{"name":"The European Physical Journal A","volume":"61 2","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epja/s10050-025-01489-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143108222","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":"Inverse temperature dependent energy diffusion in positive and negative temperature regimes for the 1d coupled rotator lattice with bounded kinetic energy","authors":"Hongbin Chen,&nbsp;Nianbei Li","doi":"10.1140/epjb/s10051-025-00866-w","DOIUrl":"10.1140/epjb/s10051-025-00866-w","url":null,"abstract":"<p>The negative temperature with Boltzmann description can be realized in Hamiltonian with bounded energy terms such as the 1d coupled rotator lattice with bounded kinetic energy. Normal heat conduction behavior has also been found for this 1d nonlinear lattice model. In this paper, we will systematically investigate the energy diffusion behavior for such 1d nonlinear lattice in both the positive and negative temperature regimes via equilibrium diffusion method. Normal energy diffusion is confirmed with Gaussian fitting and inverse temperature dependent energy diffusion constants are obtained over the whole temperature range.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143108238","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":"Ultra high energy cosmic rays versus models of high energy hadronic interactions","authors":"Blaž Bortolato,&nbsp;Jernej F. Kamenik,&nbsp;Michele Tammaro","doi":"10.1140/epjc/s10052-025-13861-3","DOIUrl":"10.1140/epjc/s10052-025-13861-3","url":null,"abstract":"<div><p>We evaluate the consistency of hadronic interaction models in the CORSIKA simulation package with publicly available fluorescence telescope data from the Pierre Auger Observatory. By comparing the first few central moments of the extensive air shower depth maximum distributions, as extracted from measured events, to those predicted by the best-fit inferred compositions, we derive a statistical measure of the consistency of a given hadronic model with data. To mitigate possible systematic biases, we include all primaries up to iron, compensate for the differences between the measured and simulated energy spectra of cosmic rays and account for other known systematic effects. Additionally, we study the effects of including higher central moments in the fit and project our results to larger statistics.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 2","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-13861-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143108215","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":"Beyond the inert doublet: imprints of Scotogenic Yukawa interactions at FCC-ee","authors":"Carlo Marzo,&nbsp;Aurora Melis","doi":"10.1140/epjc/s10052-025-13802-0","DOIUrl":"10.1140/epjc/s10052-025-13802-0","url":null,"abstract":"<div><p>It is tempting to interpret the minuscule scale of neutrino masses as a symptom of its radiative origin. In light of the notable leap in precision expected at the Future Circular Collider, we explore areas of the parameter space that can simultaneously support the detectable Higgs-strahlung signal with parallel ones from forthcoming measurements in low-energy observables. We pinpoint the role that the extra fermions have in shaping a signal distinct from the pure Inert Doublet one. The details of the full one-loop computation and on-shell renormalization are presented. Both normal and inverted hierarchies for the radiatively generated neutrino masses and angles are investigated.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 2","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-13802-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143108275","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}