The European Physical Journal C最新文献

{"title":"QCD factorization for the (B rightarrow gamma ell nu _{ell }) decay beyond leading power","authors":"Bo-Yan Cui,&nbsp;Yue-Long Shen,&nbsp;Chao Wang,&nbsp;Yan-Bing Wei","doi":"10.1140/epjc/s10052-025-14772-z","DOIUrl":"10.1140/epjc/s10052-025-14772-z","url":null,"abstract":"<div><p>The radiative leptonic <span>(B rightarrow gamma ell nu _{ell })</span> decay serves as an ideal platform to determine the <i>B</i>-meson inverse moment which is a fundamental nonperturbative parameter for the <i>B</i> meson. In this paper, we explore precise QCD contributions to this decay with an energetic photon. We reproduce the next-to-next-to-leading-logarithmic resummation formula for the decay amplitude at leading power in <span>(Lambda _textrm{QCD}/m_b)</span>. Employing operator identities, we calculate subleading-power contributions from the expansion of the hard-collinear propagator of the internal up quark and the heavy-quark expansion of the bottom quark. We update the contributions from the hadronic structure of the photon to the <span>(B rightarrow gamma ell nu _{ell })</span> process with the dispersion technique. Together with other yet known power corrections, phenomenological applications including the partial branching fraction and ratio of the branching fractions of the radiative <i>B</i> decay are investigated.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 9","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14772-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145168214","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":"Publisher Erratum: (b rightarrow c) semileptonic sum rule: extension to angular observables","authors":"Motoi Endo,&nbsp;Syuhei Iguro,&nbsp;Tim Kretz,&nbsp;Satoshi Mishima,&nbsp;Ryoutaro Watanabe","doi":"10.1140/epjc/s10052-025-14757-y","DOIUrl":"10.1140/epjc/s10052-025-14757-y","url":null,"abstract":"","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 9","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14757-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145110466","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":"The optical analogy between a Lorentz-violating cosmos and a magneto-electric medium","authors":"Iman Motie,&nbsp;Brahim Lamine,&nbsp;Alain Blanchard,&nbsp;Rémy Battesti,&nbsp;Carlo Rizzo","doi":"10.1140/epjc/s10052-025-14755-0","DOIUrl":"10.1140/epjc/s10052-025-14755-0","url":null,"abstract":"<div><p>The goal of our study is to investigate the effects of Lorentz symmetry violation by examining the behavior of photons within the framework of the Standard Model Extension (SME). We show that, from an optical point of view, the Lorentz-violating cosmos is analogous to a magneto-electric medium like the quantum vacuum in the presence of the magnetic and electric field. This analogy provides a formulation for exploring experimental evidence of Lorentz symmetry violation in the propagation of light in a vacuum, in particular in the case of a radiation background observed like the CMB.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 9","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14755-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145110456","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":"The constraints on the stochastic gravitational wave background from cosmic strings by an electromagnetic resonance system","authors":"Jin Li,&nbsp;Meijin Li,&nbsp;Nan Yang,&nbsp;Li Wang,&nbsp;Hao Yu,&nbsp;Yingzhou Huang,&nbsp;Kai Lin,&nbsp;Zi-Chao Lin,&nbsp;Fangyu Li","doi":"10.1140/epjc/s10052-025-14765-y","DOIUrl":"10.1140/epjc/s10052-025-14765-y","url":null,"abstract":"<div><p>As one of the primary detection targets for contemporary gravitational wave (GW) observatories, the stochastic gravitational wave background (SGWB) holds significant potential for enhancing our understanding of the early universe’s formation and evolution. Studies indicate that the SGWB spectrum from cosmic strings can span an extraordinarily broad frequency range, extending from extremely low frequencies up to the microwave band. This work specifically investigates the detectability of cosmic string SGWB signals in an electromagnetic (EM) resonance system at GHz frequency. We present a systematic analysis encompassing: (1) the response of high frequency gravitational waves (HFGWs) in such EM resonance system. (2) The development and application of fundamental data processing protocols in the EM resonance system. Our results demonstrate that the EM system shows promising sensitivity to detect cosmic string SGWB signals with tension parameters <span>(Gmu ge 10^{-11})</span> (the corresponding dimensionless amplitude <span>(h ge 10^{-33})</span> at 1 GHz), while potentially establishing new constraints for <span>(Gmu le 10^{-11})</span> in the microwave band. These findings would complement existing multi-band SGWB observations and provide additional constraints on cosmic-string tension parameters in GHz frequency regimes.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 9","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14765-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145110529","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":"Sea quark-gluon effect on the magnetic octupole deformation of decuplet baryons","authors":"Preeti Bhall,&nbsp;Ritu Garg,&nbsp;Alka Upadhyay","doi":"10.1140/epjc/s10052-025-14786-7","DOIUrl":"10.1140/epjc/s10052-025-14786-7","url":null,"abstract":"<div><p>The magnetic octupole moment of <span>(J^P= frac{3}{2}^+)</span> decuplet baryons are discussed in the statistical framework, treating baryons as an ensembles of quark-gluon Fock states. The probabilities associated with multiple strange and non-strange Fock states depict the importance of sea in spin, flavor &amp; color space, which are further merged into statistical parameters. The individual contribution of valence and sea (scalar, vector and tensor) to the magnetic octupole moment is calculated. The symmetry breaking in both sea and valence is experienced by a suppression factor <span>(k(1-C_l)^{n-1})</span> and a mass correction parameter ’r’, respectively. The factor <span>(k(1-C_l)^{n-1})</span> systematically reduces the probabilities of Fock states containing multiple strange quark pairs. The octupole moment value is obtained −ve for <span>(Delta ^{++}, Delta ^+, Sigma ^{*+})</span> and +ve for <span>(Delta ^{-}, Sigma ^{*-}, Xi ^{*-}, Omega ^-)</span> baryons with the domination of scalar (spin-0) sea. The computed results are compared with existing theoretical predictions, demonstrating good consistency. These predictions may serve as valuable inputs for future high-precision experiments and theoretical explorations in hadron structure.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 9","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14786-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145100651","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":"Gravitational lensing and shadow around a non-minimally coupled Horndeski black hole in plasma medium","authors":"Shubham Kala,&nbsp;Jaswinder Singh","doi":"10.1140/epjc/s10052-025-14793-8","DOIUrl":"10.1140/epjc/s10052-025-14793-8","url":null,"abstract":"<div><p>We investigate the light deflection and the shadow characteristics of a non-minimally coupled Horndeski black hole surrounded by a magnetized, cold, pressureless plasma medium, while considering both homogeneous and non-homogeneous plasma distributions. We consider an analytical expression for the deflection angle of light and analyze how it is influenced by the plasma properties and the Horndeski coupling constant. The circular light orbits, which define the photon sphere, are also analyzed for both types of plasma media, highlighting their impact on the shadow boundary. The shadow properties of the black hole are examined in detail, and constraints on the model parameters are derived by comparing the theoretical shadow radius with observational measurements of Sgr A* and M87* obtained by the Event Horizon Telescope Collaboration. We also study the black hole shadow images along with the corresponding intensity profiles produced by a radially infalling accretion flow in the plasma environment. The results are particularly interesting, as they reveal how the modified black hole geometry affects both the plasma distribution and the black hole parameters in a realistic astrophysical context.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 9","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14793-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145110605","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":"Critical phenomenon of quantum BTZ black holes","authors":"Hong-Ming Cui,&nbsp;Zhong-Ying Fan","doi":"10.1140/epjc/s10052-025-14768-9","DOIUrl":"10.1140/epjc/s10052-025-14768-9","url":null,"abstract":"<div><p>We extend the thermodynamics of quantum BTZ black holes by treating the quantum backreaction strength parameter <span>(nu )</span> as a thermodynamic variable. We find various novel features. The critical point appears at <span>(nu _c=1)</span> and a first order transition occurs either below the critical temperature for <span>(nu &lt;nu _c)</span> or above the critical temperature for <span>(nu &gt;nu _c)</span>. By solving the coexistence curve analytically, we analyze the phase structures and clarify an unexpected discontinuity around the critical point. The critical exponents are significantly different from the mean field theory results and violate one of the scaling laws. We present an intepretation for this by using a universal three scale factor hypothesis for critical behavior of thermodynamic potential. Finally, we prove that given an arbitrarily small angular momenta, only one stable black hole phase can exist and hence no transition will occur.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 9","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14768-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145100653","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":"Scheme of integration of vacuum F(R) gravity in a travelling wave variable","authors":"Maria V. Shubina","doi":"10.1140/epjc/s10052-025-14763-0","DOIUrl":"10.1140/epjc/s10052-025-14763-0","url":null,"abstract":"<div><p>In this article we propose the scheme of integration of two-dimensional <i>F</i>(<i>R</i>) gravity vacuum equations in a travelling wave variable. The main emphasis is placed on the fundamental possibility of obtaining different forms of the function <i>F</i>(<i>R</i>) by arbitrarily choosing a certain function through which all components of the metric tensor of the theory can be expressed.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 9","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14763-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145100601","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":"Gravitational collapse in pure Gauss–Bonnet theory","authors":"Akshay Kumar,&nbsp;Ayan Chatterjee,&nbsp;Suresh C. Jaryal","doi":"10.1140/epjc/s10052-025-14785-8","DOIUrl":"10.1140/epjc/s10052-025-14785-8","url":null,"abstract":"<div><p>In this paper, we study the gravitational collapse of matter fields, which include dust, perfect fluids as well as fluids admitting bulk and shear viscosity. The initial conditions on these matter fields have been kept to be quite general: the initial velocity profile of the matter is taken to include both the bound and the marginally bound models, while the density profile of the initial matter configuration is assumed to have physically admissible portrayal, and smooth falloffs. We determine, under these general conditions, the time of formation of the central singularity and the formation and evolution of black hole horizons, depicted here in terms of quasilocal marginally trapped surfaces. Our study shows that under these general conditions, the central singularity remains hidden from the asymptotic observer.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 9","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14785-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145100650","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":"The anholonomic frame and connection deformation method for constructing off-diagonal solutions in (modified) Einstein gravity and nonassociative geometric flows and Finsler–Lagrange–Hamilton theories","authors":"Laurenţiu Bubuianu,&nbsp;Julia O. Seti,&nbsp;Douglas Singleton,&nbsp;Panayiotis Stavrinos,&nbsp;Sergiu I. Vacaru,&nbsp;Elşen Veli Veliev","doi":"10.1140/epjc/s10052-025-14545-8","DOIUrl":"10.1140/epjc/s10052-025-14545-8","url":null,"abstract":"<div><p>This article is a status report on the anholonomic frame and connection deformation method, AFCDM, for constructing generic off-diagonal exact and parametric solutions in general relativity, GR, relativistic geometric flows and modified gravity theories, MGTs. Such models can be generalized to nonassociative and noncommutative star products on phase spaces and modelled equivalently as nonassociative Finsler–Lagrange–Hamilton geometries. Our approach involves a nonholonomic geometric reformulation of classical models of gravitational and matter fields described by Lagrange and Hamilton densities on relativistic phase spaces. Using nonholonomic dyadic variables, the Einstein equations in GR and MGTs can formulated as systems of nonlinear partial differential equations, PDEs, which can be decoupled and integrated in some general off-diagonal forms. In this approach, the Lagrange and Hamilton dynamics and related models of classical and quantum evolution, are equivalently described in terms of generalized Finsler-like or canonical metrics and (nonlinear) connection structures on deformed phase spaces defined by solutions of modified Einstein equations. New classes of exact and parametric solutions in (nonassociative) MGTs are formulated in terms of generating and integration functions and generating effective/matter sources. The physical interpretation of respective classes of solutions depends on the type of (non) linear symmetries, prescribed boundary/asymptotic conditions or posed Cauchy problems. We consider possible applications of the AFCDM with explicit examples of off-diagonal deformations of black holes, cylindrical metrics and wormholes, black ellipsoids and torus configurations. In general, such solutions encode nonassociative and/or with geometric flow variables. For another types of generic off-diagonal (nonassociative) solutions, we study models with nonholonomic cosmological solitonic and spheroid deformations involving vertices and solitonic vacua for voids. We emphasize that such new classes of generic off-diagonal solutions can not be considered, in general, in the framework of the Bekenstein–Hawking entropy paradigm. This motivates relativistic/nonassociative phase space extensions of the G. Perelman thermodynamic approach to geometric flows and MGTs defined by nonholonomic Ricci solitons. In Appendix, Tables 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, summarize the AFCDM for various classes of quasi-stationary and cosmological solutions in MGTs with 4-d and 10-d spacetimes and (nonassociative) phase space variables on (co) tangent bundles.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 9","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14545-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145110608","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}