The European Physical Journal C最新文献

{"title":"Updated results for kinematic factors in double beta decays","authors":"S. Ghinescu,&nbsp;S. Stoica","doi":"10.1140/epjc/s10052-026-15656-6","DOIUrl":"10.1140/epjc/s10052-026-15656-6","url":null,"abstract":"<div><p>Accurate calculations of phase space factors (PSFs), electron energy spectra and angular correlations are essential for designing and interpreting double-beta decay (DBD) experiments. These quantities help maximize sensitivity to potential signals, distinguish between different decay modes and interpret the data. In this work we provide updated results for these kinematic factors for two-neutrino (<span>(2nu beta beta )</span>) and neutrinoless (<span>(0nu beta beta )</span>) decay modes, including electron-emission, positron-emission and electron capture transitions. The calculations are performed with an adapted Dirac-Hartree-Fock-Slater method which allows for orthogonality of the wave functions of electrons and positrons in bound and continuum states and incorporates relevant atomic features such us screening, finite nuclear size, exchange corrections and phase shift effects. We provide tables with updated PSFs calculated both in the closure approximation and using the Taylor expansion method, for a large number of DBD isotopes. We discuss the impact of individual atomic corrections and find that our results are in line with predictions reported in recent literature. In some specific cases we find differences between our PSF values and those previously reported which are worth considering for better prediction and interpretation of DBD data. Then, we provide numerical values for <span>(^{76}text {Ge})</span>, <span>(^{100}text {Mo})</span>, <span>(^{130}text {Te})</span> and <span>(^{136}text {Xe})</span>, which are most investigated in current DBD experiments. Similar data for other isotopes are available upon request.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 5","pages":""},"PeriodicalIF":4.8,"publicationDate":"2026-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-15656-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829406","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":"Probing quantum corrected Kazakov–Solodukhin black holes through QPOs and thin accretion disks","authors":"Sardor Murodov,&nbsp;Islom Egamberdiev,&nbsp;Otabek Umarov,&nbsp;Javlon Rayimbaev,&nbsp;Erkaboy Davletov,&nbsp;Ikram Davletov","doi":"10.1140/epjc/s10052-026-15636-w","DOIUrl":"10.1140/epjc/s10052-026-15636-w","url":null,"abstract":"<div><p>We investigate the geodesic motion and accretion disc signatures of the Kazakov–Solodukhin (KS) quantum-corrected black hole. This regular solution incorporates leading-order quantum effects into the Schwarzschild geometry. For massive test particles, we compute the innermost stable circular orbit (ISCO) together with the corresponding energy and angular momentum. We also derive the fundamental frequencies of radial and vertical oscillations and apply them to standard models of quasi-periodic oscillations (QPOs). In addition, we examine thin accretion discs using the Novikov–Thorne framework, focusing on the flux, temperature distribution, and spectral luminosity. Compared with the Schwarzschild case, the KS spacetime shows apparent differences in ISCO location, oscillation frequencies, and disc emission profiles, all of which are governed by the deformation parameter. By comparing our models with current observational QPO data, we show that this spherically symmetric spacetime cannot fit the data better than the Schwarzschild metric. Additionally, although the KS quantum-corrected black hole predicts distinct spectral properties, we cannot resolve the degeneracy between the quantum correction parameter and other astrophysical parameters (such as mass accretion rate, inclination angle, and black hole spin).\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 5","pages":""},"PeriodicalIF":4.8,"publicationDate":"2026-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-15636-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829495","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":"(B_c) meson decays into S-wave charmonium plus light meson pairs in the perturbative QCD approach","authors":"Jia-Ying Wang,&nbsp;Jing Jiang,&nbsp;Yu-Jie Liu,&nbsp;Da-Cheng Yan,&nbsp;Zhou Rui,&nbsp;Zhen-Jun Xiao,&nbsp;Ya Li","doi":"10.1140/epjc/s10052-026-15727-8","DOIUrl":"10.1140/epjc/s10052-026-15727-8","url":null,"abstract":"<div><p>In this work, we explore the <i>P</i>-wave resonance contributions to the quasi-two-body charmonium decays of <span>(B_crightarrow Psi (Vrightarrow ) P_1P_2)</span> using the perturbative QCD formalism at leading order, where <span>(Psi )</span> denotes a <i>S</i>-wave charmonium state, such as <span>(eta _c(1S,2S),J/psi )</span>, and <span>(psi (2S))</span>. Here, <span>(P_1P_2)</span> represents a collinear <span>(pi pi )</span> (<span>(Kpi )</span>) pair in the final state, which was primarily produced through the vector resonance <span>(rho (770))</span> (<span>(K^*(892))</span> ). The contributions from the excited <span>(rho ^{prime }(1450))</span>, <span>(rho ^{prime prime }(1700))</span> and <span>(rho ^{prime prime prime }(2254))</span> resonances are also taken into account in the <span>(pi pi )</span> invariant-mass spectrum. With the improved two-meson distribution amplitudes determined from our previous works, we examined the <i>CP</i>-averaged branching ratios and polarization fractions of the considered quasi-two-body decays. The longitudinal polarization fractions of the <span>(B_crightarrow [J/psi ,psi (2,S)](rho ^+(770)rightarrow )pi ^+pi ^0)</span> and <span>(B_crightarrow [J/psi ,psi (2,S)](K^{*+}rightarrow )K^0pi ^+)</span> decays are found to be as large as <span>(sim 90%)</span>, since the transverse amplitudes from the dominant factorizable emission diagrams are always power suppressed with respect to the longitudinal ones. The direct <i>CP</i> violations in <span>(B_crightarrow Psi (Vrightarrow ) P_1P_2)</span> decays are predicted naturally to be zero as they solely receive contributions from tree diagrams. Several interesting relative ratios among the branching fractions of the concerned processes are investigated. In particular, the obtained ratio <span>(R^textrm{PQCD}_{2pi /pi }equiv mathcal {B}(B^+_c rightarrow J/psi rho ^+(770)rightarrow J/psi pi ^+pi ^0)/{mathcal {B}(B^+_c rightarrow J/psi pi ^+)}=2.67^{+0.26}_{-0.18})</span> is consistent well with the LHCb measurement <span>(R^textrm{exp}_{2pi /pi }=2.80pm 0.25)</span>. Other similar ratios proposed in this work can be tested by LHCb experiments in the near future.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 5","pages":""},"PeriodicalIF":4.8,"publicationDate":"2026-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-15727-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829494","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":"Particle production, absorption, scattering, and geodesics in a Schwarzschild–Hernquist black hole","authors":"N. Heidari,&nbsp;A. A. Araújo Filho,&nbsp;P. H. M. Barros","doi":"10.1140/epjc/s10052-026-15664-6","DOIUrl":"10.1140/epjc/s10052-026-15664-6","url":null,"abstract":"<div><p>We investigate quantum and classical signatures of a Schwarzschild black hole embedded in a Hernquist dark matter halo. Starting from the exact spherically symmetric solution describing this composite system, we analyze particle production for both bosonic and fermionic fields using semiclassical techniques. Hawking radiation is derived through Bogoliubov transformations and independently via the tunneling method with energy conservation, allowing us to identify the effective temperature, emission spectrum, and the role of dark matter parameters in suppressing particle creation. The evaporation process is examined in the high-frequency regime, leading to modified evaporation times and emission rates relative to the vacuum Schwarzschild case. We further study absorption and scattering of massless scalar waves employing a partial-wave analysis, computing phase shifts, partial and total cross sections, and assessing the impact of the Hernquist scale radius and density on these observables. Finally, null and timelike geodesics are explored to characterize light propagation and particle motion in the presence of the dark matter halo.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 5","pages":""},"PeriodicalIF":4.8,"publicationDate":"2026-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-15664-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829243","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":"Proof-of-concept of a xenon-based cryogenic heat pump demonstrator for future liquid xenon observatories","authors":"P. Schulte,&nbsp;D. Wenz,&nbsp;L. Althüser,&nbsp;R. Braun,&nbsp;V. Hannen,&nbsp;C. Huhmann,&nbsp;D. Koke,&nbsp;Y.-T. Lin,&nbsp;P. Unkhoff,&nbsp;C. Weinheimer","doi":"10.1140/epjc/s10052-026-15739-4","DOIUrl":"10.1140/epjc/s10052-026-15739-4","url":null,"abstract":"<div><p>This manuscript details the proof-of-concept of a small-scale cryogenic heat pump demonstrator, a technology designed to enable high-flow xenon distillation systems for the removal of <span>(^{222})</span>Rn in future liquid xenon observatories such as the XLZD experiment. The heat pump demonstrator operates on a left-turning Clausius–Rankine cycle, utilizing xenon as a phase-changing working medium. The design aims to fully hermetically separate the heat pump from the radon removal system, simplifying material cleanliness and maintenance compared to currently operating systems. Two demonstration tests were conducted at nominal pressures of 3.3 bar and 4.3 bar, utilizing a cold head and electrical heaters to mimic the behavior of a xenon distillation system. In both measurements, the demonstrator achieved a cooling and heating power of 118 ± 3 W and 121 ± 3 W, respectively. This is sufficient to operate a small distillation system with a virtual purification mass flow of about 3.1 kg/h, while consuming 386 ± 1 W electrical power. Compared to currently operating applications using commercial cold heads driven by helium compressors, which typically require about 6 kW of electrical power, this is significantly lower. The presented proof-of-concept heat pump demonstrator is further put into perspective with the currently planned XLZD experiment using a simplified scaling model. This model indicates that a radon removal system with a purification mass flow of 1600 kg/h and a required cooling and heating power of about 60 kW each will be sufficient to cover a variety of different detector masses and background conditions.\u0000\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 5","pages":""},"PeriodicalIF":4.8,"publicationDate":"2026-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-15739-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829496","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":"Quenching factors for Na recoils as a function of Tl dopant concentrations in NaI(Tl) crystals","authors":"G. Angloher,&nbsp;M. R. Bharadwaj,&nbsp;A. Böhmer,&nbsp;M. Cababie,&nbsp;I. Colantoni,&nbsp;I. Dafinei,&nbsp;N. Di Marco,&nbsp;C. Dittmar,&nbsp;L. Einfalt,&nbsp;F. Ferella,&nbsp;F. Ferroni,&nbsp;S. Fichtinger,&nbsp;A. Filipponi,&nbsp;T. Frank,&nbsp;M. Friedl,&nbsp;M. Gapp,&nbsp;L. Gai,&nbsp;Z. Ge,&nbsp;M. Heikinheimo,&nbsp;M. N. Hughes,&nbsp;K. Huitu,&nbsp;M. Kellermann,&nbsp;R. Maji,&nbsp;M. Mancuso,&nbsp;L. Pagnanini,&nbsp;F. Petricca,&nbsp;S. Pirro,&nbsp;F. Pröbst,&nbsp;G. Profeta,&nbsp;A. Puiu,&nbsp;F. Reindl,&nbsp;K. Schäffner,&nbsp;J. Schieck,&nbsp;P. Schreiner,&nbsp;C. Schwertner,&nbsp;K. Shera,&nbsp;M. Stahlberg,&nbsp;A. Stendahl,&nbsp;M. Stukel,&nbsp;C. Tresca,&nbsp;F. Wagner,&nbsp;S. Yue,&nbsp;V. Zema,&nbsp;Y. Zhu,&nbsp;P. S. Barbeau,&nbsp;S. C. Hedges,&nbsp;C. Awe,&nbsp;J. Runge,&nbsp;T. Johnson,&nbsp;D. M. Markoff,&nbsp;P. An,&nbsp;C. G. Prior,&nbsp;A. Bracho,&nbsp;S. Alawabdeh","doi":"10.1140/epjc/s10052-026-15738-5","DOIUrl":"10.1140/epjc/s10052-026-15738-5","url":null,"abstract":"<div><p>Thallium-doped sodium iodide (NaI(Tl)) scintillation detectors play an important role in the field of direct dark matter (DM) searches. The DAMA/LIBRA experiment stands out for its reported observation of an annually modulating DM-like signal, which is in direct contrast with other results. To accurately calibrate the energies of nuclear recoil signals with electron recoils, precise measurements of the quenching factor of the NaI(Tl) crystals are essential, as the two processes have different scintillation light yield. In this article, we present results of a systematic study carried out by the COSINUS collaboration and Duke University to measure the quenching factor of sodium (Na) recoils as a function of nuclear recoil energy and for differing Thallium (Tl) dopant concentrations in the bulk crystal. Five ultrapure NaI(Tl) crystals, manufactured by the Shanghai Institute for Ceramics, were irradiated with a quasi-monoenergetic neutron beam at the Triangle Universities Nuclear Laboratory, North Carolina, USA. The quenching factor for nuclear recoils off Na with low energies of 6–26keV<span>(_{text {nr}})</span> was extracted for all crystals, using two proportional calibration schemas with lines from a <span>(^{241})</span>Am source and a <span>(^{133})</span>Ba source. A Tl-dependence could be deduced in both cases, where a lower Tl concentration leads to smaller observed QF.\u0000\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 5","pages":""},"PeriodicalIF":4.8,"publicationDate":"2026-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-15738-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829653","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":"Three-loop singularity structure for a non-linear sigma model","authors":"P. V. Akacevich,&nbsp;A. V. Ivanov,&nbsp;I. V. Korenev","doi":"10.1140/epjc/s10052-026-15534-1","DOIUrl":"10.1140/epjc/s10052-026-15534-1","url":null,"abstract":"<div><p>The paper is devoted to the three-loop renormalization of the effective action for a two-dimensional non-linear sigma model using the background field method and a cutoff regularization in the coordinate representation. The coefficients of the renormalization constant and the necessary auxiliary vertices are found, as well as the asymptotic expansions of all three-loop diagrams, and their dependence on the type of regularizing function. A comparison is also made with the standard case of cutoff in the momentum representation.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 5","pages":""},"PeriodicalIF":4.8,"publicationDate":"2026-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-15534-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829654","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":"Decoherence, perturbations and symmetry in Lindblad dynamics: implications for diffractive dissociation","authors":"A. Y. Klimenko","doi":"10.1140/epjc/s10052-026-15689-x","DOIUrl":"10.1140/epjc/s10052-026-15689-x","url":null,"abstract":"<div><p>We extend a perturbative Dyson-type treatment and discrete-symmetry constraints from the Schrödinger and von Neumann equations to a dephasing Lindblad framework. This work develops further the odd-symmetric formulation involving dual temporal conditions from general dynamical considerations to specific tools of quantum mechanics. Applying the resulting scaling relations to published single- and double-diffractive data in <i>pp</i> and <span>(pbar{p})</span> collisions (ISR, UA4, UA5, CDF, D0, ALICE, and E710), we show that single-diffraction cross sections are well described by a three-parameter fit with a relative RMS deviation of <span>(sim 4%,)</span> substantially improving upon conventional approximations that neglect decoherence. The extracted decoherence factor is consistently <span>(phi approx 0.89,)</span> in agreement across SD, DD, and E710-based (direct) estimates, and is naturally interpreted as <span>(phi =1)</span> for CP-invariant dephasing but <span>(phi &lt;1)</span> for CPT-invariant dephasing, favouring the latter.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 5","pages":""},"PeriodicalIF":4.8,"publicationDate":"2026-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-15689-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829227","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":"Black holes with multiple horizons without mass inflation","authors":"Changjun Gao,&nbsp;Saken Toktarbay","doi":"10.1140/epjc/s10052-026-15643-x","DOIUrl":"10.1140/epjc/s10052-026-15643-x","url":null,"abstract":"<div><p>Mass inflation is a phenomenon occurring in the vicinity of the inner horizon in a spacetime with two horizons. It is shown that the mass of initially small perturbations grows exponentially as they approach the inner horizon. This implies that the inner horizon of a black hole is unstable under perturbations. Since mass inflation is determined by the surface gravities of the inner horizons, Carballo-Rubio et al. showed that if one makes the surface gravities of the inner horizons vanish, then the exponential growth associated with mass inflation is not present. Based on this conclusion, we look for the black hole solutions of multiple horizons in the presence of a nonlinear Maxwell field. We then make the inner horizons coincide with each other such that the surface gravities of all inner horizons vanish. In this way, black holes with multiple horizons without mass inflation are constructed.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 5","pages":""},"PeriodicalIF":4.8,"publicationDate":"2026-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-15643-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829652","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":"(f_K/f_{pi }) in iso-symmetric QCD and the CKM matrix unitarity","authors":"Alessandro Conigli,&nbsp;Julien Frison,&nbsp;Alejandro Sáez","doi":"10.1140/epjc/s10052-026-15670-8","DOIUrl":"10.1140/epjc/s10052-026-15670-8","url":null,"abstract":"<div><p>We present lattice results for <span>(f_K/f_{pi })</span> in the iso-symmetric limit of pure QCD (isoQCD) with <span>(N_f=2+1)</span> flavours, along with a determination of <span>(|V_{us}|/|V_{ud}|)</span> and a study on the unitarity of the first row of the Cabibbo–Kobayashi–Maskawa (CKM) matrix after introducing strong isospin-breaking and QED effects. The results obtained are based on a combination of a Wilson unitary action and the mixed-action setup introduced in Bussone et al. (Hadronic physics from a Wilson fermion mixed-action approach: setup and scale setting. http://arxiv.org/abs/2510.20450; Eur Phys J C 84:506, 2024. http://arxiv.org/abs/2309.14154). The combination of the two regularisations enables a more precise control over the continuum-limit extrapolation.\u0000\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 5","pages":""},"PeriodicalIF":4.8,"publicationDate":"2026-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-15670-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829655","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}