Physics Letters B最新文献

{"title":"The irreversible relaxation of inflation","authors":"Robert Alicki ,&nbsp;Gabriela Barenboim ,&nbsp;Alejandro Jenkins","doi":"10.1016/j.physletb.2025.139519","DOIUrl":"10.1016/j.physletb.2025.139519","url":null,"abstract":"<div><div>Based on the results of a previous analysis of the Markovian master equation for the irreversible evolution of an open system embedded in de Sitter space <span><span>[7]</span></span>, we include in the cosmological Friedmann equations a contribution from the presence of a physical bath at temperature <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>dS</mi></mrow></msub><mo>=</mo><mi>h</mi><mo>/</mo><mn>2</mn><mi>π</mi></math></span>, where <em>h</em> is the Hubble parameter. We show that this provides a mechanism for the irreversible relaxation of the cosmological constant and a graceful exit to inflation, without need for subsequent reheating. Thermal particle production during inflation gives adiabatic, Gaussian, and approximately scale-invariant cosmological perturbations. We thus obtain the main features of inflation without any inflaton potential. To clarify the thermodynamic interpretation of these results, we consider the analogy of this irreversible relaxation to superfluorescence in quantum optics.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"866 ","pages":"Article 139519"},"PeriodicalIF":4.3,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143907128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quasinormal modes of massive scalar fields in five-dimensional Myers-Perry black holes with two arbitrary rotation parameters","authors":"Zi-Yang Huang ,&nbsp;Jia-Hui Huang","doi":"10.1016/j.physletb.2025.139514","DOIUrl":"10.1016/j.physletb.2025.139514","url":null,"abstract":"<div><div>We investigate the quasinormal modes of massive scalar fields in the background of five-dimensional Myers-Perry black holes. In particular, we explore the case for Myers-Perry black holes with two arbitrary rotation parameters. Since the Klein-Gordon equation for the scalar field is separable, we numerically compute the scalar quasinormal modes by using the radial and angular equations. Two methods, the continued fraction method and matrix method, are used in the numerical calculation. We find that all obtained modes have negative imaginary parts and are decaying modes. We also consider the impact of the rotation parameters, scalar field mass <em>μ</em> and azimuthal numbers on the scalar quasinormal modes. Besides, when the scalar mass <em>μ</em> becomes relatively large, we also find the long-living scalar modes. Our numerical results also demonstrate the symmetries of the QNMs explicitly.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"866 ","pages":"Article 139514"},"PeriodicalIF":4.3,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143912959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Time-dependent solutions of biadjoint scalar field theories","authors":"Kymani Armstrong-Williams,&nbsp;Chris D. White","doi":"10.1016/j.physletb.2025.139517","DOIUrl":"10.1016/j.physletb.2025.139517","url":null,"abstract":"<div><div>Biadjoint scalar field theories appear in the study of scattering amplitudes and classical solutions in gauge, gravity and related theories. In this paper, we present new exact solutions of biadjoint scalar field theory, showing that time-dependent solutions are possible and analytically tractable. We generalise the theory to include mass and / or quartic terms, and also a coupling to a constant current. This allows for more exact solutions, which make contact with previous soliton literature. We also find bounded solutions, in contrast to all known previous examples. Our results may be useful for the study of non-perturbative aspects of the double copy between gauge theories and gravity. We also speculate as to their possible practical applications.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"866 ","pages":"Article 139517"},"PeriodicalIF":4.3,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143903339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nuclear α-cluster structures from valence-space microscopic cluster model","authors":"Zhen Wang ,&nbsp;Dong Bai ,&nbsp;Zhongzhou Ren","doi":"10.1016/j.physletb.2025.139518","DOIUrl":"10.1016/j.physletb.2025.139518","url":null,"abstract":"<div><div>Alpha clustering is an important dynamic in nuclear physics, with growing interest to its study in heavy nuclei in recent years. Theoretically, the microscopic cluster models taking nucleons as relevant degrees of freedom have been widely used to study <em>α</em>-cluster structures in light nuclei. However, a straightforward application on same footing in heavy nuclei is obstructed by the complexity of handling numerous nucleons. As a simplified alternative, the macroscopic cluster models built upon cluster degrees of freedom are usually employed in heavy nuclei, though these approaches typically lose several critical structural details. In this work, we propose to study the <em>α</em>-cluster structures within the framework of valence-space microscopic cluster model (VS-MCM), which is a hybrid between microscopic and macroscopic cluster models and inherits features from both models, making it capable to investigate the <em>α</em>-cluster structures in heavy nuclei from a relatively microscopic viewpoint. In VS-MCM, the valence <em>α</em> clusters are described by antisymmetrized microscopic wave functions, with single-particle orbits in core nuclei removed systematically from the model space via the Pauli projection to simulate the antisymmetrization between <em>α</em> clusters and doubly magic cores. As a proof of principle, we apply the VS-MCM to study the <em>α</em>-cluster structures in ²⁰Ne and ⁴⁴Ti at first, with the theoretical energy levels of the <span><math><msup><mrow><mi>K</mi></mrow><mrow><mi>π</mi></mrow></msup><mo>=</mo><msubsup><mrow><mn>0</mn></mrow><mrow><mn>1</mn></mrow><mrow><mo>±</mo></mrow></msubsup></math></span> bands for ²⁰Ne and ⁴⁴Ti showing reasonable agreement with experimental data. These calculations lay the foundation for future applications of VS-MCM in general cluster structures across the nuclide chart, where more <em>α</em> clusters and valence nucleons can exist outside the heavy doubly magic core, opening new avenues to study the <em>α</em> and cluster decays in heavy nuclei microscopically.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"866 ","pages":"Article 139518"},"PeriodicalIF":4.3,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143918123","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Probing medium response via strangeness enhancement around quenched jets","authors":"Ao Luo ,&nbsp;Shanshan Cao ,&nbsp;Guang-You Qin","doi":"10.1016/j.physletb.2025.139520","DOIUrl":"10.1016/j.physletb.2025.139520","url":null,"abstract":"<div><div>Jet-induced medium excitation is a crucial part of jet interactions with the quark-gluon plasma (QGP) in relativistic heavy-ion collisions, and has recently been confirmed by experiment for the first time. Based on the AMPT model simulation, we propose the strangeness enhancement around quenched jets as a novel signature of jet-induced medium excitation. By applying the jet-particle correlation techniques, we calculate jet-induced particle yields around the jets and find a significant enhancement of the strange-to-non-strange-hadron ratio and the double-to-single-strange-hadron ratio correlated with jets in relativistic nucleus-nucleus collisions relative to proton-proton collisions. This enhancement increases with both the strength of jet-QGP interactions and the radial distance from jet axis. These observations align with the features of jet-induced medium excitation and parton coalescence in hadron formation, and await experimental validation in the future measurements.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"866 ","pages":"Article 139520"},"PeriodicalIF":4.3,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143907127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Good tachyons, bad bradyons: Role reversal in Einstein-nonlinear-electrodynamics models","authors":"Marco A.A. de Paula ,&nbsp;Haroldo C.D. Lima Junior ,&nbsp;Pedro V.P. Cunha ,&nbsp;Carlos A.R. Herdeiro ,&nbsp;Luís C.B. Crispino","doi":"10.1016/j.physletb.2025.139513","DOIUrl":"10.1016/j.physletb.2025.139513","url":null,"abstract":"<div><div>In relativistic mechanics, the 4-velocity and the 4-momentum need not be parallel. This allows their norm to have a different sign. This possibility occurs in nonlinear electrodynamics (NED) models minimally coupled to Einstein's theory. Surprisingly, for a large class of NED models with a Maxwell limit, for weak fields, the causal (acausal) photons, as determined by their 4-velocity, have a spacelike (timelike) 4-momentum, leading to good tachyons and bad bradyons. Departing from weak fields, this possibility is determined solely by the concavity of the NED Lagrangian, which is consistent with the Dominant Energy Condition analysis. As a corollary, some popular regular black hole solutions sourced by NED, such as the Bardeen and Hayward solutions, are acausal.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"866 ","pages":"Article 139513"},"PeriodicalIF":4.3,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143899482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Relativistic low-momentum interactions from renormalization group","authors":"Tianxing Huang ,&nbsp;Yilong Yang ,&nbsp;Jie Meng ,&nbsp;Peter Ring ,&nbsp;Pengwei Zhao","doi":"10.1016/j.physletb.2025.139502","DOIUrl":"10.1016/j.physletb.2025.139502","url":null,"abstract":"<div><div>The relativistic <span><math><msub><mrow><mi>V</mi></mrow><mrow><mrow><mi>low</mi></mrow><mspace></mspace><mi>k</mi></mrow></msub></math></span> is developed from a renormalization group method for the first time, to provide softened <em>NN</em> interactions for relativistic <span><math><mi>a</mi><mi>b</mi><mspace></mspace><mi>i</mi><mi>n</mi><mi>i</mi><mi>t</mi><mi>i</mi><mi>o</mi></math></span> calculations. Starting from a given bare <em>NN</em> interaction, the renormalization group method eliminates the repulsive core while keeping the low-energy on-shell <em>T</em>-matrix and, consequently, the two-body observables unchanged. We derive the relativistic <span><math><msub><mrow><mi>V</mi></mrow><mrow><mrow><mi>low</mi></mrow><mspace></mspace><mi>k</mi></mrow></msub></math></span> interactions from the relativistic Bonn <em>NN</em> interactions across a wide range of cutoffs and study nuclear matter using the relativistic Brueckner-Hartree-Fock theory in the full Dirac space. Our results demonstrate that the resulting relativistic <span><math><msub><mrow><mi>V</mi></mrow><mrow><mrow><mi>low</mi></mrow><mspace></mspace><mi>k</mi></mrow></msub></math></span> interactions provide a proper description of nuclear saturation, exhibiting only mild cutoff dependence. Therefore, the relativistic <span><math><msub><mrow><mi>V</mi></mrow><mrow><mrow><mi>low</mi></mrow><mspace></mspace><mi>k</mi></mrow></msub></math></span> shows promise for providing reliable softened <em>NN</em> interactions for future relativistic <span><math><mi>a</mi><mi>b</mi><mspace></mspace><mi>i</mi><mi>n</mi><mi>i</mi><mi>t</mi><mi>i</mi><mi>o</mi></math></span> calculations of finite nuclei.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"866 ","pages":"Article 139502"},"PeriodicalIF":4.3,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143899484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Two-body Dirac equation in DSR: Results for fermion-antifermion pairs","authors":"Nosratollah Jafari ,&nbsp;Abdullah Guvendi","doi":"10.1016/j.physletb.2025.139515","DOIUrl":"10.1016/j.physletb.2025.139515","url":null,"abstract":"<div><div>This study investigates a modified two-body Dirac equation in <span><math><mn>2</mn><mo>+</mo><mn>1</mn></math></span>-dimensional spacetime, inspired by Amelino-Camelia's doubly special relativity (DSR). We begin by deriving a covariant two-body Dirac equation that, in the absence of DSR modifications, reduces to a Bessel-type wave equation. Incorporating corrections from the chosen DSR model modifies this wave equation, yielding solutions consistent with established results in the low-energy regime. We demonstrate that the effects of DSR modifications become particularly pronounced at large relative distances. For a coupled fermion-antifermion pair, we derive the modified binding energy solutions. By accounting for first-order Planck-scale corrections, we show that the fine-structure constant <em>α</em> behaves as an energy-dependent running parameter, given by <span><math><msub><mrow><mi>α</mi></mrow><mrow><mtext>eff</mtext></mrow></msub><mo>(</mo><mi>E</mi><mo>)</mo><mo>/</mo><mi>α</mi><mo>≈</mo><mn>1</mn><mo>−</mo><mfrac><mrow><mi>E</mi></mrow><mrow><mn>4</mn><msub><mrow><mi>E</mi></mrow><mrow><mi>p</mi></mrow></msub></mrow></mfrac></math></span>, where <span><math><msub><mrow><mi>E</mi></mrow><mrow><mi>p</mi></mrow></msub></math></span> is the Planck energy. Binding energy levels are computed using a first-order approximation of the DSR modifications, and the results are applied to positronium-like systems. Our model reveals that DSR modifications induce shifts in the binding energy levels. To the best of our knowledge, DSR-modified two-body equations have not been previously studied. This model is the first of its kind, opening new avenues for further research in this area.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"866 ","pages":"Article 139515"},"PeriodicalIF":4.3,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143894314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Does the Amati correlation exhibit redshift-driven heterogeneity in long GRBs?","authors":"Darshan Singh ,&nbsp;Meghendra Singh ,&nbsp;Dinkar Verma ,&nbsp;Kanhaiya Lal Pandey ,&nbsp;Shashikant Gupta","doi":"10.1016/j.physletb.2025.139500","DOIUrl":"10.1016/j.physletb.2025.139500","url":null,"abstract":"<div><div>Long gamma-ray bursts (GRBs) offer significant insights into cosmology due to their high energy emissions and the potential to probe the early universe. The Amati relation, which links the intrinsic peak energy to the isotropic energy, is crucial for understanding their cosmological applications. This study investigates the redshift-driven heterogeneity of the Amati correlation in long GRBs. We analyzed 221 long GRBs with redshifts from 0.034 to 8.2, dividing them by redshift thresholds of 1.5 and 2. Using Bayesian marginalization and Reichart's likelihood approach, we found significant differences in the Amati parameters between low and high redshift subgroups. These variations, differing by approximately 2<em>σ</em> at <span><math><mi>z</mi><mo>=</mo><mn>1.5</mn></math></span> and more than 1<em>σ</em> at <span><math><mi>z</mi><mo>=</mo><mn>2</mn></math></span>, suggest an evolution in the GRB population with redshift, possibly reflecting changes in host galaxy properties. The Akaike and Bayesian Information Criteria also confirm these results. However, selection effects and instrumental biases may also contribute to it. Our results challenge the assumption of the Amati relation's universality and underscore the need for larger datasets and more precise measurements from upcoming missions like Transient High-Energy Sky and Early Universe Surveyor (THESEUS), and enhanced X-ray Timing and Polarimetry mission (eXTP) to refine our understanding of GRB physics.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"866 ","pages":"Article 139500"},"PeriodicalIF":4.3,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143894313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The 33311 left-right bilepton model","authors":"Claudio Corianò ,&nbsp;Paul H. Frampton ,&nbsp;Dario Melle","doi":"10.1016/j.physletb.2025.139498","DOIUrl":"10.1016/j.physletb.2025.139498","url":null,"abstract":"<div><div>We discuss extension of the electroweak gauge group to <span><math><mi>S</mi><mi>U</mi><msub><mrow><mo>(</mo><mn>3</mn><mo>)</mo></mrow><mrow><mi>L</mi></mrow></msub><mo>×</mo><mi>S</mi><mi>U</mi><msub><mrow><mo>(</mo><mn>3</mn><mo>)</mo></mrow><mrow><mi>R</mi></mrow></msub><mo>×</mo><mi>U</mi><msub><mrow><mo>(</mo><mn>1</mn><mo>)</mo></mrow><mrow><mi>L</mi></mrow></msub><mo>×</mo><mi>U</mi><msub><mrow><mo>(</mo><mn>1</mn><mo>)</mo></mrow><mrow><mi>R</mi></mrow></msub></math></span>, based on the principle that anomaly cancellation may inherently involve three fermion generations. The explanation for three light quark-lepton families remains, but new particles are introduced which have no TeV scale upper limit on their masses. This approach, originally realized in the framework of the 331 Model, has been consistently defined up to the TeV scale. Our approach maintains the 331 Model's natural explanation for three light quark-lepton families, while introducing new physics with no upper bound on its energy scale.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"866 ","pages":"Article 139498"},"PeriodicalIF":4.3,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143903340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}