The European Physical Journal C最新文献

Scattering, bound states, and resonances in the one-dimensional Dirac equation via supersymmetric quantum mechanics 透过超对称量子力学，一维狄拉克方程中的散射、束缚态和共振

IF 4.9 2区物理与天体物理

The European Physical Journal C Pub Date : 2026-09-01 DOI: 10.1140/epjc/s10052-026-16228-4

Camila C. Soares, Luis B. Castro, Antonio S. de Castro

{"title":"Scattering, bound states, and resonances in the one-dimensional Dirac equation via supersymmetric quantum mechanics","authors":"Camila C. Soares, Luis B. Castro, Antonio S. de Castro","doi":"10.1140/epjc/s10052-026-16228-4","DOIUrl":"10.1140/epjc/s10052-026-16228-4","url":null,"abstract":"<div><p>We develop a unified treatment of scattering and discrete spectra for the one-dimensional Dirac equation with scalar and vector interactions. Under the spin-symmetry condition, the coupled first-order Dirac system maps exactly onto an effective Sturm–Liouville (Schrödinger-like) problem for a single spinor component. This mapping provides a convenient framework for analyzing transmission, reflection, and analytic continuation. As an explicit application, we consider effective interactions of hyperbolic Pöschl–Teller type and exploit supersymmetric quantum mechanics and shape invariance to obtain a closed-form expression for the transmission probability. The bound-state spectrum is then recovered from the poles of the analytically continued transmission amplitude, reproducing known results and offering a unified description of scattering and bound states. For the barrier configuration, we briefly comment on the resulting pole pattern in the complex momentum plane and its connection with resonance and quasi-normal-mode behavior. Moreover, we use the chiral transformation to relate the spin- and pseudospin-symmetry sectors and translate results between them without repeating the full derivation.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 9","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-16228-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148859778","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}

引用次数: 0

Grey-body factors and thermodynamics of asymptotically de Sitter black holes in generalized Proca theory 广义Proca理论中渐近de Sitter黑洞的灰体因子和热力学

IF 4.9 2区物理与天体物理

The European Physical Journal C Pub Date : 2026-09-01 DOI: 10.1140/epjc/s10052-026-16289-5

Bekir Can Lütfüoğlu, Javlon Rayimbaev, Nuriddin Kurbonov, Sardor Murodov, Faisal Javed

{"title":"Grey-body factors and thermodynamics of asymptotically de Sitter black holes in generalized Proca theory","authors":"Bekir Can Lütfüoğlu, Javlon Rayimbaev, Nuriddin Kurbonov, Sardor Murodov, Faisal Javed","doi":"10.1140/epjc/s10052-026-16289-5","DOIUrl":"10.1140/epjc/s10052-026-16289-5","url":null,"abstract":"<div><p>Generalized Proca theory supplements gravity with a massive vector field whose derivative self-interactions can support black holes carrying primary vector hair. In the asymptotically de Sitter branch considered here, the de Sitter scale is effective: it is generated by the vector sector rather than imposed through a bare cosmological-constant term. We compute grey-body factors and effective absorption cross-sections for massive scalar, electromagnetic, and massless Dirac test fields on this background. The transmission curves are obtained from a sixth-order WKB barrier calculation and are compared with the quasinormal-mode reconstruction; the two descriptions mostly agree, with small visible differences at lower multipoles. Increasing the scalar mass raises and broadens the scalar barrier, suppresses transmission at fixed frequency, and shifts efficient transmission to higher frequencies. The couplings considerably affect the grey-body factors and black hole thermodynamics.\u0000\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 9","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-16289-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148859779","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}

引用次数: 0

Black hole entropy beyond the wald term in nonminimally coupled gravity: a covariant phase space decomposition 非最小耦合引力中沃尔德项以外的黑洞熵：一种协变相空间分解

IF 4.9 2区物理与天体物理

The European Physical Journal C Pub Date : 2026-09-01 DOI: 10.1140/epjc/s10052-026-16290-y

Jia-Zhou Liu, Shan-Ping Wu, Shao-Wen Wei, Yu-Xiao Liu

{"title":"Black hole entropy beyond the wald term in nonminimally coupled gravity: a covariant phase space decomposition","authors":"Jia-Zhou Liu, Shan-Ping Wu, Shao-Wen Wei, Yu-Xiao Liu","doi":"10.1140/epjc/s10052-026-16290-y","DOIUrl":"10.1140/epjc/s10052-026-16290-y","url":null,"abstract":"<div><p>We study the entropy of static, spherically symmetric black holes in diffeomorphism-invariant theories with nonminimal matter–curvature couplings, using the covariant phase space formalism. For regular bifurcate Killing horizons, the Iyer–Wald construction gives the standard Wald entropy. If a matter field cannot be smoothly extended to the regular bifurcation surface, however, the entropy-sector horizon surface charge variation can contain finite contributions that are not included in the Wald entropy density. In the representative obtained by directly varying the action, and after ordinary non-gravitational boundary terms have been separated into the work sector, we decompose the entropy entering the first law of black hole thermodynamics as <span>(S_{mathrm H}=S_{mathrm W}+S_1+varDelta S)</span>. Here <span>(S_{mathrm W})</span> is the Wald entropy, <span>(S_1)</span> is the non-Wald part of the entropy-sector Noether charge, and <span>(varDelta S)</span> is the remaining integrable part of the entropy-sector horizon surface charge variation. Applying this criterion to Kalb–Ramond, bumblebee, and extended Gauss–Bonnet black holes, we find that the regular Kalb–Ramond branch has <span>(S_{mathrm H}=S_{mathrm W})</span>, the bumblebee branches yield either <span>(S_1=0)</span> with <span>(varDelta Sne 0)</span> or a cancellation between <span>(S_1)</span> and <span>(varDelta S)</span>, and the Weyl-vector extended Gauss–Bonnet examples require both corrections. This provides a direct test of whether the Wald density is sufficient or whether the full horizon surface charge variation is required.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 9","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-16290-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148859780","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}

引用次数: 0

Exact rotating dilatonic branch in ModMax electrodynamics without Maxwell analogue 在没有麦克斯韦模拟的ModMax电动力学中精确旋转扩张分支

IF 4.9 2区物理与天体物理

The European Physical Journal C Pub Date : 2026-08-29 DOI: 10.1140/epjc/s10052-026-16268-w

Leonel Bixano, Tonatiuh Matos

{"title":"Exact rotating dilatonic branch in ModMax electrodynamics without Maxwell analogue","authors":"Leonel Bixano, Tonatiuh Matos","doi":"10.1140/epjc/s10052-026-16268-w","DOIUrl":"10.1140/epjc/s10052-026-16268-w","url":null,"abstract":"<div><p>We present a novel class of rotating dilatonic solutions within the framework of Einstein–ModMax-type gravity. The configuration belongs to the nonlinear sector characterized by <span>(mathcal F/mathcal G=textrm{const})</span> and carries nontrivial electric and magnetic potentials, with both <span>(A_t)</span> and <span>(A_varphi )</span> turned on, together with a nontrivial gravitomagnetic structure. We show that this solution does not admit continuation to the Maxwell framework of our parametrization, so it is intrinsically tied to the nonlinear ModMax regime. It includes both a NUT geometry and a NUT-free asymptotically flat limit, and it is valid for a broad class of dilatonic couplings, including the low-energy string and Kaluza–Klein cases. Moreover, in the prolate sector we identify a genuine black-hole regime in which the exterior region satisfies the null energy condition while the curvature singularity remains hidden behind the event horizon. These results provide an exact rotating dilatonic ModMax configuration with no Maxwell analog and a physically well-behaved exterior black-hole sector.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 8","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-16268-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148838375","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}

引用次数: 0

A unified study of hidden-charm and hidden-bottom mesons 隐藏魅力和隐藏底介子的统一研究

IF 4.9 2区物理与天体物理

The European Physical Journal C Pub Date : 2026-08-28 DOI: 10.1140/epjc/s10052-026-16266-y

Vikas Patel, Chetan Lodha, A. K. Rai

{"title":"A unified study of hidden-charm and hidden-bottom mesons","authors":"Vikas Patel, Chetan Lodha, A. K. Rai","doi":"10.1140/epjc/s10052-026-16266-y","DOIUrl":"10.1140/epjc/s10052-026-16266-y","url":null,"abstract":"<div><p>We present a unified phenomenological analysis of hidden-charm and hidden-bottom mesons, treating the <span>(cbar{c})</span> and <span>(bbar{b})</span> sectors within a common screened-potential and QCD sum-rule framework. The mass spectra are obtained from a screened Coulomb-plus-confining interaction with spin-dependent corrections, while the short-distance decay constants, annihilation widths and electromagnetic transition form factors are organized through two-point and three-point QCD sum rules. The same calculated states are then used to study E1 and M1 radiative transitions, Regge trajectories and finite-spectrum thermodynamic observables constructed from excitation energies relative to the corresponding ground states. The results are discussed together rather than as disconnected outputs: the mass spectra determine the state assignments, the Regge plots test the global level ordering, the radiative widths probe orbital and spin-flip overlap integrals, and the QCD sum-rule quantities connect the spectrum to current-coupled observables. The comparison of the two hidden-flavour sectors shows the expected compression and stronger spin suppression in bottomonium, while charmonium remains more sensitive to fine-structure, radial-node and medium-related effects. The resulting picture provides a coherent vacuum benchmark for <span>(cbar{c})</span> and <span>(bbar{b})</span> spectroscopy, radiative transitions and QCD sum-rule observables.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 8","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-16266-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148838399","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}

引用次数: 0

Learning to bin: differentiable and Bayesian optimization for multi-dimensional discriminants in high-energy physics 学习bin：高能物理中多维判别式的可微分和贝叶斯优化

IF 4.9 2区物理与天体物理

The European Physical Journal C Pub Date : 2026-08-27 DOI: 10.1140/epjc/s10052-026-16255-1

Johannes Erdmann, Nitish Kumar Kasaraguppe Veerappa Gowda, Florian Mausolf

{"title":"Learning to bin: differentiable and Bayesian optimization for multi-dimensional discriminants in high-energy physics","authors":"Johannes Erdmann, Nitish Kumar Kasaraguppe Veerappa Gowda, Florian Mausolf","doi":"10.1140/epjc/s10052-026-16255-1","DOIUrl":"10.1140/epjc/s10052-026-16255-1","url":null,"abstract":"<div><p>Categorizing events using discriminant observables is central to many high-energy physics analyses. Yet, bin boundaries are often chosen manually. A simple, popular choice in multi-classification tasks is to assign events according to the largest per-class score (“argmax”) and to apply equidistant binning to the resulting one-dimensional discriminants. We propose a binning optimization for signal significance directly in multi-dimensional discriminants. We use a Gaussian Mixture Model (GMM) to define flexible regions in the score space, which can be interpreted either as bins or as analysis categories. While this GMM-based strategy is applicable in both one and multiple dimensions, we also study a direct bin-boundary optimization in one dimension as a simpler alternative for binary discriminants. On this binning model, we study two optimization strategies: a differentiable and a Bayesian optimization approach. We study two toy setups: a binary classification and a three-class problem with two signals and backgrounds. In the one-dimensional case, both approaches achieve similar gains in signal sensitivity compared to equidistant binning for a given number of bins, while in the multi-dimensional case the differentiable approach performs best. We show that the GMM-based optimization can outperform argmax classification even after optimized binning is applied to the one-dimensional projections. We further study the performance of our methods on the FAIR Universe <span>(Hrightarrow tau tau )</span> dataset, where the GMM-based optimization gives the highest signal significance. Both methods are released as lightweight Python plugins intended for straightforward integration into existing analyses.\u0000\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 8","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-16255-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148838378","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}

引用次数: 0

On gravitational collapse and integrable singularities 关于引力坍缩和可积奇点

IF 4.9 2区物理与天体物理

The European Physical Journal C Pub Date : 2026-08-27 DOI: 10.1140/epjc/s10052-026-16258-y

Roberto Casadio, Andrea Giusti, Alexander Kamenshchik, Jorge Ovalle

引用次数: 0

Bjorken flow of holographic R-charged plasmas 全息r电荷等离子体的比约肯流

IF 4.9 2区物理与天体物理

The European Physical Journal C Pub Date : 2026-08-27 DOI: 10.1140/epjc/s10052-026-16257-z

Gustavo de Oliveira, Willians Barreto, Romulo Rougemont

引用次数: 0

Projections of H(rightarrow tau tau ) cross-section at FCC-ee H (rightarrow tau tau )截面在FCC-ee的投影

IF 4.9 2区物理与天体物理

The European Physical Journal C Pub Date : 2026-08-27 DOI: 10.1140/epjc/s10052-026-16238-2

S. Giappichini, M. Klute, M. Presilla, X. Zuo, M. Cepeda

{"title":"Projections of H(rightarrow tau tau ) cross-section at FCC-ee","authors":"S. Giappichini, M. Klute, M. Presilla, X. Zuo, M. Cepeda","doi":"10.1140/epjc/s10052-026-16238-2","DOIUrl":"10.1140/epjc/s10052-026-16238-2","url":null,"abstract":"<div><p>The Future Circular Collider (FCC) stands at the forefront of the European Strategy for Particle Physics as the future flagship project at CERN. The H<span>(rightarrow tau tau )</span> decay, featuring a large branching ratio, clean identification in the FCC-ee environment, and the possibility to reconstruct tau spin-related observables, is an excellent channel to measure Higgs boson properties. This work shows the expected precision for the H<span>(rightarrow tau tau )</span> cross-section measurement at the FCC-ee in the ZH production mechanism at <span>(sqrt{s}=)</span> 240 GeV and <span>(sqrt{s}=)</span> 365 GeV, as well as via the vector boson fusion process at <span>(sqrt{s}=)</span> 365 GeV. Furthermore, we explore and evaluate a set of methods for reconstructing tau decays. These techniques are critical for unlocking the full physics potential of the FCC-ee and for improving the understanding of tau-related observables in both Standard Model measurements and New Physics searches. The obtained results significantly enhance the FCC-ee outlook in the H<span>(rightarrow tau tau )</span> channel, improving it by at least an order of magnitude compared to the current uncertainties on the cross-sections measured at the LHC.\u0000\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 8","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-16238-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148838377","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}

引用次数: 0

Tensor-current contributions to B anomalies 张量电流对B异常的贡献

IF 4.9 2区物理与天体物理

The European Physical Journal C Pub Date : 2026-08-27 DOI: 10.1140/epjc/s10052-026-16237-3

Qiaoyi Wen, Fanrong Xu

{"title":"Tensor-current contributions to B anomalies","authors":"Qiaoyi Wen, Fanrong Xu","doi":"10.1140/epjc/s10052-026-16237-3","DOIUrl":"10.1140/epjc/s10052-026-16237-3","url":null,"abstract":"<div><p>Tensor-current operators, potentially generated by scalar leptoquarks in grand unified theories (GUTs), are among the plausible new physics (NP) candidates suggested by the anomalies observed in <i>B</i>-meson decays. As experimental data continue to accumulate, exploring this possibility remains timely and well motivated. In this work, we present a systematic analysis of representative tensor-current Wilson coefficients (<span>(C_T, C_{T5})</span>) in <span>(b rightarrow s ell ^+ ell ^-)</span> transitions. By incorporating contributions from the high-<span>(q^2)</span> region, our framework fully exploits the available experimental data across the entire <span>(q^2)</span> range. Within this setup, five distinct lepton-flavor-universal (LFU) scenarios are proposed and tested through global fits. Our results show that it is difficult to resolve the tension between experimental measurements and theoretical predictions using only <span>(C_T)</span> and <span>(C_{T5})</span>. Meanwhile, the significance of <span>(Delta C_9)</span> remains essentially unchanged, even in the presence of tensor contributions. In one representative scenario (S-III), we obtain <span>([Delta C_9,Delta C_{10}, C_T, C_{T5}] simeq [-1.00,,0.22,,0.01,,0.01])</span>, with a reduced chi-squared statistic <span>(tilde{chi }^2 equiv chi ^2_textrm{min}/mathrm{d.o.f.} = 658.5/437 = 1.51)</span>. Furthermore, we derive a stringent 95% C.L. constraint on tensor operators, </p><div><div><span>$$begin{aligned} F(x,y)Big |^{text {S-I}}_{x=Delta C_T,,y=Delta C_{T5}}= & x^2 + 0.071,xy + 0.942 & y^2 + 0.091,x + 0.044,y le 0, end{aligned}$$</span></div></div><p>which provides a strong bound to date on <span>(C_T)</span> and <span>(C_{T5})</span>.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 8","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-16237-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148837990","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}

引用次数: 0