The European Physical Journal C最新文献

{"title":"Publisher Correction: Phenomenology of the Higgs sector from reduction of couplings in the Type-II 2HDM","authors":"Wojciech Kotlarski, Gregory Patellis","doi":"10.1140/epjc/s10052-026-16327-2","DOIUrl":"10.1140/epjc/s10052-026-16327-2","url":null,"abstract":"","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 9","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-16327-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149034910","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":"Strong decay widths of S- and P-wave singly- and doubly-heavy charm and bottom baryons","authors":"Emmanuel Ortiz-Pacheco,&nbsp;Roelof Bijker","doi":"10.1140/epjc/s10052-026-16344-1","DOIUrl":"10.1140/epjc/s10052-026-16344-1","url":null,"abstract":"<div><p>We present a study of two-body decay widths of heavy baryons into another heavy baryon and a light pseudoscalar meson in the framework of the non-relativistic quark model in combination with the elementary emission model for the strong couplings. The present study includes the decays of 1<i>S</i>- and 1<i>P</i>-wave baryons with one or two heavy quarks, either charm (<i>c</i>) or bottom (<i>b</i>). The flavor, spin and orbital contributions are discussed explicitly as well as selection rules for forbidden decays. The relative partial widths are given by the appropriate flavor <i>SU</i>(3) isoscalar factors. The total widths are compared with the available experimental data as well as with other theoretical studies. The calculated widths of singly-heavy baryons are found to be in reasonable agreement with the observed widths. The decay widths of doubly-heavy baryons are suppressed with respect to those of the singly-heavy baryons by the ratios of the quark masses appearing in the orbital contributions.\u0000\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 9","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-16344-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149034827","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":"Padé semi-cosmographic reconstruction of residual dark energy in decaying dark matter cosmology: DESI DR2 BAO constraints and mock 21 cm forecasts","authors":"Mohit Yadav,&nbsp;Pankaj Chavan,&nbsp;Tapomoy Guha Sarkar","doi":"10.1140/epjc/s10052-026-16335-2","DOIUrl":"10.1140/epjc/s10052-026-16335-2","url":null,"abstract":"<div><p>Pure cosmographic reconstructions provide a model-agnostic approach towards constraining cosmic evolution. We develop a hybrid phenomenological semi-cosmographic framework that adopts a Padé-rational fraction parametrization of the luminosity distance, and incorporates a phenomenologically motivated two-body decaying dark matter (DDM) sector. In this framework, the effective residual dark-energy equation of state is obtained by subtracting the contributions of DDM, baryons, and radiation from the Padé approximation to the expansion history under the assumptions of flat FLRW cosmology and the standard Friedmann equations. Cosmological observables computed from these semi-cosmographic quantities are fitted to the data to reconstruct cosmological evolution. We present two separate analyses. First, we perform a data fit to the current DESI DR2 BAO measurements. Second, we report a forecast based on an optimistic mock 21 cm intensity-mapping power spectrum at <span>(zsimeq 1.75)</span> for a SKA1-MID-like instrument, used jointly with the DESI DR2 BAO data. The forecast serves as proof of concept to demonstrate a possible improvement in model constraints when measurements of the 21 cm power spectrum complement the BAO background observables. Posterior constraints on the Padé and DDM parameters are obtained using Markov Chain Monte Carlo (MCMC) analysis, and we present the corresponding equations of state of the massive daughter and the effective reconstructed dark energy.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 9","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-16335-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149034918","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":"GPT-like transformer model for silicon tracking detector simulation","authors":"Tadej Novak,&nbsp;Borut Paul Kerševan","doi":"10.1140/epjc/s10052-026-16362-z","DOIUrl":"10.1140/epjc/s10052-026-16362-z","url":null,"abstract":"<div><p>Simulating physics processes and detector responses is essential in high energy physics and represents significant computing costs. Generative machine learning has been demonstrated to be potentially powerful in accelerating simulations, outperforming traditional fast simulation methods. The efforts have focused primarily on calorimeters. This work presents the very first studies on using neural networks for silicon tracking detectors simulation. The GPT-like transformer architecture is determined to be optimal for this task and applied in a fully generative way, ensuring full correlations between individual hits. Taking parallels from text generation, hits are represented as a flat sequence of feature values. The resulting tracking performance, evaluated on the Open Data Detector, is comparable with the full simulation.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 9","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-16362-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149034723","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":"Construction and characterisation of the DarkSide-20k veto silicon photo-multiplier tiles","authors":"DarkSide-20k Collaboration","doi":"10.1140/epjc/s10052-026-16217-7","DOIUrl":"10.1140/epjc/s10052-026-16217-7","url":null,"abstract":"<div><p>Silicon photo-multipliers (SiPMs) are state-of-the-art sensors capable of detecting a single photoelectron under cryogenic conditions, with potentially lower radioactivity than widely used photomultiplier tubes. The DarkSide-20k experiment, designed to perform direct dark matter searches using liquid argon as the target material, employs SiPM technology to detect interactions in the active detector volumes, including the central dual-phase Time Projection Chamber and the Inner and Outer Veto volumes. The vetoes are designed to discriminate against radiogenic neutron and cosmic muon backgrounds associated with the dark matter search. This paper describes the completed production and test protocols for the “Veto Tiles” (called <i>vTiles</i>, arrays of 24 SiPMs integrated on a printed circuit board providing the power distribution and signal amplification); 16 vTiles are grouped into “Veto Photo-Detector Units” to instrument the Inner Veto volume. Each vTile underwent detailed testing at room and cryogenic temperatures, confirming stable operation, high signal-to-noise ratio, and low radioactive contamination, demonstrating the robustness of the proposed design for cryogenic conditions. The final production yield exceeded 87%, surpassing the 80% requirement and corresponding to 1920 Veto Tiles to populate 120 Veto Photo-Detector Units, plus an additional 6% as spares.\u0000\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 9","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13593779/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149023674","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":"No late-time role for adiabatic torsion: a no-go result for Hubble-cutoff holographic dark energy in Einstein–Cartan cosmology","authors":"Fernando Izaurieta,&nbsp;Samuel Lepe,&nbsp;Cristian Quinzacara","doi":"10.1140/epjc/s10052-026-16337-0","DOIUrl":"10.1140/epjc/s10052-026-16337-0","url":null,"abstract":"<div><p>In Friedmann cosmology with Einstein–Cartan torsion, the homogeneous torsion mode compatible with a separately conserved matter sector scales as <span>(Phi propto a^{-3})</span> and enters the Friedmann constraint as a stiff component of negative energy density, <span>(-3Phi ^{2}propto a^{-6})</span>. It has recently been claimed that this mode rescues the Hubble radius as an infrared cutoff for holographic dark energy, producing late-time acceleration and a phantom-divide crossing of possible relevance to DESI. We show that it cannot. With the Hubble cutoff the holographic density drops out of the deceleration parameter, and the only accelerating regime is the transient window <span>(bar{a}le a&lt;4^{1/3}bar{a})</span> around the torsion bounce at <span>(H(bar{a})=0)</span>; placing that window at observable redshifts would force the Hubble rate to vanish in our recent past, against the measured expansion history. Requiring a viable history yields nested upper bounds on <span>(Omega _{Phi }equiv (Phi _{0}/H_{0})^{2})</span>: fitting the official DESI DR2 BAO likelihood gives <span>(Omega _{Phi }&lt;8.7times 10^{-4})</span> (<span>(95%)</span> CL), the existence of a spectroscopically confirmed galaxy at <span>(z=14.32)</span> gives <span>(8.4times 10^{-5})</span>, the CMB gives <span>(3.1times 10^{-10})</span>, and Big Bang nucleosynthesis gives <span>(5times 10^{-24})</span>. Today’s imprint on the dark energy equation of state, <span>(|1+omega _{0}|le 2Omega _{Phi }/Omega _{Lambda })</span>, falls short of the DESI preference by two orders of magnitude at best and twenty-two at worst, and on the phantom side. In the Granda–Oliveros cutoff, torsion deepens rather than prevents the big-rip singularity. An appendix derives the Friedmann pair from the Einstein–Cartan field equations and shows that the <span>(a^{-3})</span> scaling is the kinematics of a diluting spin fluid; escaping the no-go requires breaking exactly that.\u0000\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 9","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-16337-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149034757","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":"Topological thermodynamics of generalized Bardeen black hole","authors":"A. A. M. Silva,&nbsp;M. H. Macêdo,&nbsp;R. R. Landim","doi":"10.1140/epjc/s10052-026-16379-4","DOIUrl":"10.1140/epjc/s10052-026-16379-4","url":null,"abstract":"<div><p>Neves and Saa introduced a two-parameter spacetime that encompasses the Bardeen and Hayward geometries as special cases, together with a case whose <i>f</i>(<i>r</i>) function has the Simpson–Visser form. In this work, we employ the off-shell generalized Helmholtz free energy method to investigate the thermodynamic properties of this family within a topological framework. We begin by constructing the associated vector field and analyzing its zeros – specifically their winding numbers – to classify the thermodynamic branches and identify critical points associated with changes in global stability. Within the thermodynamic setup adopted here, the Bardeen, Hayward, and Simpson–Visser-type cases do not define independent global topological classes: whenever the off-shell conditions allow for two regular zeros, their winding numbers are <span>(w=+1)</span> and <span>(w=-1)</span>, resulting in a total topological number of <span>(W=0)</span>. Within the more recent universal thermodynamic-topology classification, this stable-to-unstable defect ordering corresponds to the previously established <span>(W^{0+})</span> class, whereas the Schwarzschild limit is consistent with the <span>(W^{1-})</span> class. The parameters <span>(alpha )</span> and <span>(beta )</span> are useful for determining the extremal bound, the critical radius, the inverse critical temperature, and the extent of the locally stable branch. In contrast, the Schwarzschild limit exhibits a monotonic curve for the inverse temperature and a single topological defect with <span>(W=-1)</span>. These results provide a unified analytical characterization of how these configurations modify the local thermodynamic structure while preserving the global topological class of cases where <i>a</i> is finite.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 9","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-16379-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149034751","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":"Evaporation of primordial black holes with multimodal mass and extended spin distributions: cosmological imprints on the effective number of relativistic species","authors":"T. Toghrai,&nbsp;A. Daassou,&nbsp;Y. Ouchhaine,&nbsp;H. Laassiri,&nbsp;R. Benbrik","doi":"10.1140/epjc/s10052-026-16372-x","DOIUrl":"10.1140/epjc/s10052-026-16372-x","url":null,"abstract":"<div><p>Primordial black holes (PBHs) form through several distinct mechanisms, each imprinting a characteristic mass function that a single-mass treatment risks erasing. Building on the <span>FRISBHEE</span> code, we introduce <span>FRISHBEE</span> (https://doi.org/10.5281/zenodo.22699162), implementing four mass functions – log-normal, power-law, critical collapse, metric preheating – in a multimodal framework, with spin modeled via Gaussian and Fishbach et al. profiles. Crucially, each channel’s weight is derived from the primordial collapse probability rather than fitted, tying the mass function to the power-spectrum amplitude – a concrete link between inflationary model-building and CMB observables. Solving the Friedmann–Boltzmann equations for <span>(M_textrm{PBH}^textrm{in}=10^{7})</span> g in the pre-BBN window, we compute <span>(varDelta N_textrm{eff})</span> for five distributions, three spin configurations, and three weighting scenarios. Extended mass functions enhance <span>(varDelta N_textrm{eff})</span> over the monochromatic benchmark by factors of <span>(sim !1.03)</span> (critical collapse) to <span>(sim !1.84)</span> (log-normal), preserving the hierarchy <span>(LN&gt; MM&gt; PL&gt; MP &gt; CC)</span> across the mass window <span>({10^{5},10^{7},10^{8}})</span> g. Near-extremal spin (<span>(a_{star }=0.99)</span>) and spin-2 dark radiation invert this trend: superradiant spin loss averages away faster in broad distributions than in a monochromatic population, letting the monochromatic approximation overestimate <span>(varDelta N_textrm{eff})</span>. Against CMB-S4 and Simons Observatory sensitivities (<span>(sigma simeq 0.06)</span> and 0.05), the monochromatic benchmark is undetectable for scalar dark radiation (sDR <span>(=0)</span>), while log-normal, power-law, and multimodal distributions reach <span>(sim !1.6)</span>–<span>(1.7sigma )</span>; for spin-2 dark radiation the signal drops over an order of magnitude, with none detectable. The formation channel thus governs the magnitude and observational accessibility of the Hawking signal, establishing <span>(varDelta N_textrm{eff})</span> as a discriminant between single- and multi-channel PBH formation scenarios.\u0000\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 9","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-16372-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149034858","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":"Curvature regularization and dynamical vacuum structure in pseudo-complex general relativity","authors":"Fridolin Weber,&nbsp;Peter O. Hess,&nbsp;Cesar A. Zen Vasconcellos","doi":"10.1140/epjc/s10052-026-16331-6","DOIUrl":"10.1140/epjc/s10052-026-16331-6","url":null,"abstract":"<div><p>Whether classical spacetime remains well-defined at arbitrarily high curvature is a central question. In general relativity, singularities signal the breakdown of the classical description, motivating modifications of spacetime’s short-distance structure. Pseudo-complex general relativity (pcGR) extends spacetime geometry to pseudo-complex coordinates, naturally introducing two metric sectors, the physical metric <span>(g_{mu nu })</span> and an auxiliary field <span>(f_{mu nu })</span>. The magnitude of the pseudo-imaginary component defines the invariant acceleration scale <span>(a_0)</span>, a direct consequence of the pseudo-complex structure. The simultaneity condition, requiring both idempotent sectors to satisfy the pseudo-complex Einstein equations independently, fixes the auxiliary field algebraically, with no new propagating degrees of freedom, and sets a lower bound on the lapse that regularizes curvature. The regularization is achieved through the combined effect of the lapse-gap condition <span>( e^{nu (r)} &gt; a_0 )</span>, which ensures the radial metric component remains nondegenerate, together with the regularity conditions at the areal-radius origin, <span>( B(0)=1 )</span> and <span>( B'(0)=0 )</span>, which emerge naturally from the pseudo-complex geometry. These conditions jointly eliminate the Schwarzschild-type curvature divergence, rather than the gap condition acting alone. In cosmology, we show that the pseudo-complex field equations admit a formal reduction to an effective evolution equation for the vacuum. component <span>(rho _textrm{pc}(t))</span>: the auxiliary functions <span>(f_0)</span> and <span>(f_2)</span>, together with <span>(ddot{a})</span>, are formally eliminated within the restricted parametrization adopted in the reduction, yielding a second-order evolution equation in which no auxiliary functions remain explicitly. The reduced evolution equation admits asymptotic solutions whose behavior is determined by the pseudo-complex geometry. In particular, it admits late-time solutions approaching an effective constant vacuum energy, suggesting a geometric origin for dark energy with scale set by <span>(a_0)</span>. pcGR thus realizes, through purely geometric conditions, bounded curvature, intrinsic cutoff scales, dynamical vacuum, and absence of global symmetries, while features depending on quantum spectra have no classical analog.\u0000\u0000\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 9","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-16331-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148986766","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 pre-geometric origin of geometric trinity of gravity","authors":"Salvatore Capozziello,&nbsp;Giuseppe Meluccio","doi":"10.1140/epjc/s10052-026-16359-8","DOIUrl":"10.1140/epjc/s10052-026-16359-8","url":null,"abstract":"<div><p>The so-called geometric trinity of gravity is based on three distinct geometric features of spacetime, i.e. curvature, torsion and non-metricity, which give rise to equivalent dynamics for general relativity (GR), teleparallel equivalent of general relativity (TEGR) and symmetric teleparallel equivalent of general relativity (STEGR). Pre-geometric gravity, on the other hand, offers a unifying framework from which all metric-affine theories can emerge. Starting from a gauge formulation <i>à la</i> Yang–Mills with a Higgs-like field, a mechanism of spontaneous symmetry breaking can give rise to an effective metric as well as to the classical dynamics of the gravitational field. In particular, the emergence of gravity in the spontaneously broken phase is shown to be consistent with all the different formulations of the geometric trinity of gravity, in terms both of actions and of gauge choices for the affine connection. This general result is achieved by deriving and analysing suitable expressions in the unbroken phase for pre-geometric actions and for pre-geometric gauge-fixing conditions respectively.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 9","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-16359-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148986856","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}