The European Physical Journal C最新文献

{"title":"Tidal Love numbers of multi-state Boson stars","authors":"Xin-Lei Zhao,&nbsp;Jun-Ru Chen,&nbsp;Yong-Qiang Wang","doi":"10.1140/epjc/s10052-026-16369-6","DOIUrl":"10.1140/epjc/s10052-026-16369-6","url":null,"abstract":"<div><p>In this paper, we calculate the tidal Love numbers of multi-state boson stars (MSBSs) composed of ground state and first excited state complex scalar fields. Under synchronized and nonsynchronized frequency conditions, the background solutions of MSBSs are classified into single-branch and double-branch types. The field functions, ADM mass, and binding energy of different solutions are discussed. We then calculate the quadrupolar (<span>(ell =2)</span>) electric and magnetic tidal Love numbers for branches containing stable solutions. Our results show that the electric tidal Love numbers are initially positive and then suddenly transition to negative values. This phenomenon occurs when the parameters satisfy <span>({tilde{mu }}_1 &gt; 0.891)</span> or <span>({tilde{omega }}_0 &gt; 0.777)</span>; for smaller values of these parameters, the electric Love numbers remain positive. The magnetic tidal Love numbers are always negative, with absolute values smaller than those of the electric tidal Love numbers.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 9","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-16369-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149132892","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":"Relativistic correction to the binding energies of two-body hadronic molecular states","authors":"Lin-Qing Song,&nbsp;Hai-Qing Zhou","doi":"10.1140/epjc/s10052-026-16420-6","DOIUrl":"10.1140/epjc/s10052-026-16420-6","url":null,"abstract":"<div><p>This study presents a systematic estimation of the relativistic correction to the binding energies of two-body hadronic molecular states by comparing the numerical solutions of Schrödinger, Salpeter, and Bethe–Salpeter (BS) equations derived from the same one-boson-exchange (OBE) interaction, with the OBE input couplings kept fixed and without refitting the potential to each bound state. All BS results are computed in the ladder approximation. The numerical results reveal a counterintuitive, coupling-dependent property: for MeV-scale binding with heavy exchanged mesons, the binding energies from the ladder BS and Schrödinger equations at the same parameters can differ by large factors. They show that shallow binding alone does not guarantee a small three-dimensional reduction effect when the interaction is short-ranged and strongly coupled. Specifically, we first benchmark the effect in a scalar model and then extend the analysis to the <span>(D{bar{D}})</span> system with hadronic form factors. In the shallow <span>(D{bar{D}})</span> region illustrated, the magnitude of the ladder BS binding energy amounts to only <span>(10%sim 30%)</span> of the Schrödinger result at the same couplings. Such large discrepancies show that calculations based on the Schrödinger or Salpeter equations should be treated with caution when fixed OBE input parameters are transferred without matching or refitting. This conclusion does not conflict with the universality of shallow bound states, which concerns low-energy observables after short-distance parameters have been matched.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 9","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-16420-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149132893","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 dark matter interactions with a RES–NOVA prototype cryogenic detector","authors":"RES–NOVA Collaboration","doi":"10.1140/epjc/s10052-026-16215-9","DOIUrl":"10.1140/epjc/s10052-026-16215-9","url":null,"abstract":"<div><p>We report on the operation of a 13 g PbWO<span>(_4)</span> crystal, grown from archaeological Pb and operated as a cryogenic calorimeter in an underground environment. Read out with a Ge thermistor, the detector achieves a low energy threshold and, for the first time, enables the derivation of a dark matter exclusion limit using PbWO<span>(_4)</span> as target material, for both spin-dependent interactions on neutrons and spin-independent interactions. Although limited in mass and not representative of the final RES–NOVA detector design, this prototype demonstrates effective control of mechanical vibrations and low-energy noise in a cryogenic system, which is a key requirement for rare-event searches. The experiment therefore provides a proof of principle for the RES–NOVA detection concept, validating the use of archaeological Pb-based PbWO<span>(_4)</span> crystals, low-background operation, and robust data-analysis procedures. These results establish a solid technological and methodological foundation for future RES–NOVA detectors employing larger target masses and advanced thermal readout technologies. \u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 9","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13616862/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149073143","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":"Resonant Enhancement for the transfer of baryon number from a CP-violating hidden sector","authors":"Can Kilic,&nbsp;Sanjay Mathai","doi":"10.1140/epjc/s10052-026-16384-7","DOIUrl":"10.1140/epjc/s10052-026-16384-7","url":null,"abstract":"<div><p>We consider a scenario where the baryon asymmetry in the SM arises from a portal coupling to a CP-violating hidden sector, without any explicit violation of baryon or lepton number in either sector. While no net baryon number is generated, equal and opposite baryon numbers can be sequestered between the two sectors in this scenario. The observed asymmetry must be generated below the electroweak scale in order to avoid washout. By considering a benchmark model incorporating the baryon portal and a minimal hidden sector, we review the prospects of this scenario. When the asymmetry is generated via the decay of top quarks, generic input parameters for the model are sufficient. If however the asymmetry is to be generated via the decay of bottom quarks, a resonant enhancement is needed to sequester the baryon number with maximal efficiency. The scenario of mesogenesis assisted by CP-violation in a hidden sector falls into this latter category. We use analytical and numerical methods to quantify the amount of resonant enhancement that can be achieved, and we remark that the mesogenesis scenario can be discovered or ruled out in full if the bounds on the relevant branching ratios can be improved by 2–3 orders of magnitude.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 9","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-16384-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149132594","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":"Direct calculation of the two-neutrino double-beta decay rate including the full lepton-energy dependence","authors":"S. A. Ghinescu,&nbsp;A. Neacsu,&nbsp;S. Stoica","doi":"10.1140/epjc/s10052-026-16356-x","DOIUrl":"10.1140/epjc/s10052-026-16356-x","url":null,"abstract":"<div><p>The calculation of the two-neutrino double-beta decay (DBD) rates has so far relied on approximations that decouple the nuclear structure from the emitted lepton kinematics. To ensure a more rigorous treatment, we propose an approach which incorporates the full interdependence between nuclear structure and lepton kinematics within a unified formula and performs calculations without resorting to these approximations. Deviations of the decay rates and electron spectra from the traditional methods, such as closure, non-closure, and Taylor expansion approximations, are presented and discussed for the isotopes <span>(^{82})</span>Se and <span>(^{136})</span>Xe. Our approach gives a more realistic description of the DBD process and paves the way for further theoretical and experimental investigations into the correlated nuclear structure interplay with emitted lepton kinematics contributing to the dynamics of the process. Extensions of this framework to other isotopes and to neutrinoless double-beta decay are currently underway.\u0000\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 9","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-16356-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149132891","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":"Gluon condensate effects on heavy quarkonium spectral functions and thermal dissociation","authors":"Fei Wang,&nbsp;Zi-qiang Zhang","doi":"10.1140/epjc/s10052-026-16323-6","DOIUrl":"10.1140/epjc/s10052-026-16323-6","url":null,"abstract":"<div><p>We investigate how gluon condensate modifies thermal spectral functions and melting patterns of heavy vector mesons, specifically charmonium and bottomonium, using an improved soft-wall anti-de Sitter/quantum chromodynamics (AdS/QCD) model. The framework is extended to finite temperature via a dilaton black hole geometry that consistently incorporates the back-reaction from the gluon condensate. We numerically track the evolution of spectral resonance peaks as functions of both temperature and gluon condensate strength. Our calculations reveal that increasing temperature systematically broadens and suppresses spectral peaks, signaling in-medium dissociation. In contrast, a stronger gluon condensate significantly mitigates peak broadening and enhances the spectral weight of both ground and excited states. This behavior indicates that the gluon condensate hinders thermal dissociation, thereby stabilizing heavy quarkonia within the quark–gluon plasma. These findings are consistent with existing studies and provide new holographic evidence for the stabilizing role of the gluon condensate from the perspective of thermal spectral functions.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 9","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-16323-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149133093","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":"(pi ), K, and p production in high-multiplicity pp collisions at (mathbf {sqrt{ s} = 13}) TeV","authors":"ALICE Collaboration","doi":"10.1140/epjc/s10052-026-16235-5","DOIUrl":"10.1140/epjc/s10052-026-16235-5","url":null,"abstract":"<div><p>This paper presents the measurement of <span>(pi ^{pm })</span>, <span>(text {K}^{pm })</span>, and p(<span>(bar{text {p}})</span>) production in high-multiplicity proton–proton collisions at <span>(sqrt{s}=13)</span> TeV at midrapidity (<span>(|y| &lt; 0.5)</span>) using the ALICE detector at the LHC. The transverse-momentum (<span>(p_textrm{T} )</span>) spectra of these particles are reported for three high-multiplicity classes. The results show a mass- and multiplicity-dependent hardening of the <span>(p_textrm{T} )</span> spectra and an enhancement of the p/<span>(pi )</span> ratio at intermediate <span>(p_textrm{T} )</span>. These features are similar to those observed in heavy-ion collisions, where quark–gluon plasma formation is expected. The new measurements have extended the highest average charged-particle multiplicity density per unit of pseudorapidity achieved in pp collisions, roughly a factor five higher than that in average inelastic pp collisions, thereby reducing the multiplicity gap between small and large collision systems. In addition, the results are further compared with previously published measurements and with model calculations obtained using distinct tunes of the PYTHIA 8 Monte Carlo generator, as well as with predictions from the EPOS4. The comparison of the <span>(p_textrm{T})</span>-integrated K/<span>(pi )</span> and p/<span>(pi )</span> ratios across different collision systems and energies suggests that particle production scales with charged-particle multiplicity, rather than with collision energy or system size. While the PYTHIA 8 tunes and the EPOS4 model are able to reproduce some of these measurements, either quantitatively or qualitatively, none of them consistently describes all observed features of the data.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 9","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-16235-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149133046","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":"Understanding the near-threshold structures in (e^+e^-) annihilation from a unified (Nbar{N})-interaction perspective","authors":"Teng Ji,&nbsp;Ulf-G. Meißner","doi":"10.1140/epjc/s10052-026-16364-x","DOIUrl":"10.1140/epjc/s10052-026-16364-x","url":null,"abstract":"<div><p>Near-threshold structures have been observed in the cross sections for <span>(e^+e^-rightarrow pbar{p})</span>, <span>(e^+e^-rightarrow nbar{n})</span>, and several non-baryonic final states in the vicinity of the <span>(Nbar{N})</span> thresholds. We investigate whether these structures can be understood as manifestations of a common <span>(Nbar{N})</span> final-state interaction. The strong <span>(Nbar{N})</span> interaction is taken from the chiral EFT description of the coupled <span>({}^3S_1)</span>-<span>({}^3D_1)</span> system constrained by low-energy <span>(Nbar{N})</span> scattering data. With this interaction fixed, the <span>(pbar{p})</span> and <span>(nbar{n})</span> cross sections are described by fitting only short-distance electromagnetic production sources, which are assumed to vary slowly over the near-threshold region. The resulting <span>(Nbar{N})</span> production amplitudes are then used as input for five inelastic hadronic channels. A simultaneous description of the near-threshold cross sections is obtained, indicating that the observed structures can be consistently interpreted as consequences of the same underlying <span>(Nbar{N})</span> dynamics, without introducing separate narrow resonances in individual channels.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 9","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-16364-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149132580","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":"Impact of interacting dark energy on the growth of matter density perturbations: observational constraints from DESI and multi-probe data","authors":"Fan Yang,&nbsp;Rongrong Zhai,&nbsp;Xiangyun Fu,&nbsp;Bing Xu,&nbsp;Kaiwen Liu,&nbsp;Chikun Ding,&nbsp;Yang Huang","doi":"10.1140/epjc/s10052-026-16366-9","DOIUrl":"10.1140/epjc/s10052-026-16366-9","url":null,"abstract":"<div><p>We investigate the impact of a non-gravitational dark sector interaction on the growth of matter density perturbations within both the interacting <i>w</i>CDM and the dynamical Chevallier–Polarski–Linder (CPL) scenarios. For <i>w</i>CDM model, we develop a parameterization for the growth rate based on a second-order approximation for the growth index <span>(gamma )</span> that explicitly includes the coupling constant <span>(alpha )</span>. Our analysis reveals a theoretical degeneracy: the coupling induces a correction <span>(Delta gamma simeq 1.1alpha )</span> in both models, allowing an interacting dark energy model to mimic the growth index predicted by certain modified gravity theories. Then, we confront the models with the latest multi-probe observations, including the Pantheon+ sample of Type Ia supernovae, Baryon Acoustic Oscillation (BAO) data from the Sloan Digital Sky Survey (SDSS) and the second data release (DR2) of the Dark Energy Spectroscopic Instrument (DESI), Cosmic Microwave Background (CMB) measurements, Hubble parameter <i>H</i>(<i>z</i>) data, and redshift-space distortion (RSD) measurements. Our analysis finds that the coupling constant is consistent with zero at approximately the <span>(3sigma )</span> and <span>(2sigma )</span> confidence levels for <i>w</i>CDM and CPL models, respectively, showing no definitive statistical evidence for a departure from the standard <span>(Lambda )</span>CDM cosmology. The observational constraints strongly disfavor the region of parameter space where interacting dark energy can mimic modified gravity, restricting the growth index to a common approximate interval of <span>(0.53 lesssim gamma lesssim 0.60)</span> for both models. This reinforces the growth index as a robust diagnostic for distinguishing between a non-minimal interaction in the dark sector and a genuine modification of gravity with current data.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 9","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-16366-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149132581","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":"PDF evolution in alternative factorisation schemes","authors":"S. Delorme,&nbsp;A. Kusina,&nbsp;A. Siódmok,&nbsp;J. Whitehead","doi":"10.1140/epjc/s10052-026-16303-w","DOIUrl":"10.1140/epjc/s10052-026-16303-w","url":null,"abstract":"<div><p>Beyond leading order, parton distribution functions (PDFs) require a choice of factorisation scheme to be defined unambiguously. Different choices of factorisation scheme lead to PDFs that satisfy modified DGLAP evolution equations, relative to the conventional <span>(overline{textrm{MS}})</span> scheme. In this paper we derive the NLO DGLAP splitting functions for PDFs in alternative factorisation schemes, including for a parametrised scheme spanning a subspace of the general factorisation-scheme space. We plot their Mellin-space counterparts, the anomalous dimensions, and study the leading large- and small-<i>x</i> behaviour, relevant to resummation. We find that the leading behaviour admits a natural interpretation as a modified effective evolution scale. This is an essential step towards being able to evolve and fit PDFs in alternative schemes for use within QCD calculations.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"86 9","pages":""},"PeriodicalIF":4.9,"publicationDate":"2026-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-026-16303-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149035001","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}