Physics Letters B最新文献

{"title":"Understanding of the BESIII measurement of (anti)hyperon-nucleon scattering","authors":"Xiao-Yun Wang ,&nbsp;Yuan Gao ,&nbsp;Xiang Liu","doi":"10.1016/j.physletb.2025.139321","DOIUrl":"10.1016/j.physletb.2025.139321","url":null,"abstract":"<div><div>Focusing on the recent measurements of the scattering processes <span><math><mover><mrow><mi>Λ</mi></mrow><mrow><mo>¯</mo></mrow></mover><mi>p</mi><mo>→</mo><mover><mrow><mi>Λ</mi></mrow><mrow><mo>¯</mo></mrow></mover><mi>p</mi></math></span> and <span><math><mi>Λ</mi><mi>p</mi><mo>→</mo><mi>Λ</mi><mi>p</mi></math></span> reported by BESIII, we offer a dynamical interpretation of the differences in the measured total and differential cross sections for both processes. This discrepancy arises because the <em>u</em>-channel contribution is forbidden for <span><math><mover><mrow><mi>Λ</mi></mrow><mrow><mo>¯</mo></mrow></mover><mi>p</mi><mo>→</mo><mover><mrow><mi>Λ</mi></mrow><mrow><mo>¯</mo></mrow></mover><mi>p</mi></math></span> but allowed for <span><math><mi>Λ</mi><mi>p</mi><mo>→</mo><mi>Λ</mi><mi>p</mi></math></span>. Additionally, we examine the enhancement effect in the forward angle region of the differential cross section for <span><math><mover><mrow><mi>Λ</mi></mrow><mrow><mo>¯</mo></mrow></mover><mi>p</mi></math></span> elastic scattering, attributed to the <em>t</em>-channel contribution. This work serves as a test to the scattering mechanism involved in these reactions.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"862 ","pages":"Article 139321"},"PeriodicalIF":4.3,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143429508","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":"A bound on light dark photon dark matter","authors":"Naoya Kitajima ,&nbsp;Shota Nakagawa ,&nbsp;Fuminobu Takahashi ,&nbsp;Wen Yin","doi":"10.1016/j.physletb.2025.139304","DOIUrl":"10.1016/j.physletb.2025.139304","url":null,"abstract":"<div><div>We derive a bound on dark photon dark matter scenarios where the dark photon mass is generated through the Higgs mechanism, based on the requirement that symmetry breaking must occur sufficiently early in the universe. We emphasize that dark photon production occurs successfully when the dark Higgs field remains in the symmetric phase due to non-thermal trapping effects. For renormalizable Higgs potentials, our bound reads<span><span><span><math><mfrac><mrow><msub><mrow><mi>m</mi></mrow><mrow><msup><mrow><mi>γ</mi></mrow><mrow><mo>′</mo></mrow></msup></mrow></msub></mrow><mrow><msub><mrow><mi>q</mi></mrow><mrow><mi>H</mi></mrow></msub><msub><mrow><mi>e</mi></mrow><mrow><mi>H</mi></mrow></msub></mrow></mfrac><mspace></mspace><mo>≫</mo><mspace></mspace><mn>60</mn><mspace></mspace><mrow><mi>eV</mi></mrow><msup><mrow><mo>(</mo><mfrac><mrow><mn>2</mn><mi>π</mi></mrow><mrow><mi>λ</mi></mrow></mfrac><mo>)</mo></mrow><mrow><mn>1</mn><mo>/</mo><mn>4</mn></mrow></msup></math></span></span></span> where <span><math><msub><mrow><mi>m</mi></mrow><mrow><msup><mrow><mi>γ</mi></mrow><mrow><mo>′</mo></mrow></msup></mrow></msub></math></span> is the dark photon mass, <span><math><msub><mrow><mi>e</mi></mrow><mrow><mi>H</mi></mrow></msub></math></span> is the gauge coupling, <span><math><msub><mrow><mi>q</mi></mrow><mrow><mi>H</mi></mrow></msub></math></span> is the charge of the dark Higgs boson, and <em>λ</em> is the Higgs quartic coupling. This constraint holds independently of any complications arising from the Schwinger effect and vortex formation in the Higgsed phase. For more general Higgs potentials such as the Coleman-Weinberg type potential, our bound yields different forms. We argue that late-time symmetry breaking of the dark U(1) symmetry satisfying our bound has only a mild impact on both the abundance and momentum distribution of dark photon dark matter, and therefore does not pose any serious problem for the dark photon dark matter scenario.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"862 ","pages":"Article 139304"},"PeriodicalIF":4.3,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143429507","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":"Einstein-Horndeski gravity and the ultra slowly evaporating black hole","authors":"Xiao Liang ,&nbsp;Yu-Sen An ,&nbsp;Chen-Hao Wu ,&nbsp;Ya-Peng Hu","doi":"10.1016/j.physletb.2025.139303","DOIUrl":"10.1016/j.physletb.2025.139303","url":null,"abstract":"<div><div>In this work, we study the evaporation behaviors of asymptotically flat charged black holes in the Einstein-Horndeski gravity theory. Based on the thermodynamics of the Horndeski black hole, we present a physical understanding of the scalar charge of the Horndeski black hole and also clarify its connection to the Einstein vector theory. As the presence of non-minimal coupling, the evaporating behaviors of the Horndeski black hole are vastly different from the Reissner-Nordstrom (RN) black hole case. Due to the different spacetime and electric field structures, the evaporation rate of the Horndeski black hole will slow down at the late stage of evaporation and thus gain a lifetime much longer than the RN black hole. These results illuminate the effect of non-minimally coupled matters on the black hole evaporation and provide clues to search for these matter fields in future observations.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"862 ","pages":"Article 139303"},"PeriodicalIF":4.3,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395737","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":"Lighting up the photon Wigner distribution via dilepton productions","authors":"Yu Shi ,&nbsp;Lin Chen ,&nbsp;Shu-Yi Wei ,&nbsp;Bo-Wen Xiao","doi":"10.1016/j.physletb.2025.139317","DOIUrl":"10.1016/j.physletb.2025.139317","url":null,"abstract":"<div><div>We present a systematic investigation of lepton pair production through photon-photon fusion processes in heavy-ion collisions. It is demonstrated that the dilepton production at a given impact parameter (<span><math><msub><mrow><mi>b</mi></mrow><mrow><mo>⊥</mo></mrow></msub></math></span>) with a fixed transverse momentum imbalance (<span><math><msub><mrow><mi>q</mi></mrow><mrow><mo>⊥</mo></mrow></msub></math></span>) can be factorized into a unified formula in terms of the Wigner photon distribution of heavy nuclei. We show that this framework provides a comprehensive description of all the relevant data from RHIC to the LHC, with a strong evidence that the quasi-real photon can be radiated not only from the nucleus as a whole, standing for the coherent contribution, but also from the sub-structures inside the nucleus, representing the incoherent contribution. Further predictions are made for the anisotropies in the correlations between <span><math><msub><mrow><mi>q</mi></mrow><mrow><mo>⊥</mo></mrow></msub></math></span>, <span><math><msub><mrow><mi>b</mi></mrow><mrow><mo>⊥</mo></mrow></msub></math></span>, and the dilepton transverse momentum (<span><math><msub><mrow><mi>P</mi></mrow><mrow><mo>⊥</mo></mrow></msub></math></span>). This will help us to constrain the photon Wigner distribution which plays a crucial role to study the gluonic matter of nucleus at small-<em>x</em> through the diffractive photoproduction processes in heavy ion collision.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"862 ","pages":"Article 139317"},"PeriodicalIF":4.3,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143418542","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":"Coupled fermion-antifermion pairs within a traversable wormhole","authors":"Abdullah Guvendi ,&nbsp;Omar Mustafa ,&nbsp;Semra Gurtas Dogan","doi":"10.1016/j.physletb.2025.139313","DOIUrl":"10.1016/j.physletb.2025.139313","url":null,"abstract":"<div><div>This study investigates the dynamics of fermion-antifermion (<span><math><mi>f</mi><mover><mrow><mi>f</mi></mrow><mo>‾</mo></mover></math></span>) pairs within a traversable wormhole (TWH) spacetime by solving the two-body covariant Dirac equation with a position-dependent mass <span><math><mi>m</mi><mo>→</mo><mi>m</mi><mo>(</mo><mi>r</mi><mo>)</mo></math></span>. In the context of a static, radially symmetric (2+1)-dimensional TWH characterized by a constant redshift function and a given shape function, we explore two Lorentz scalar potentials: (i) a Coulomb-like potential and (ii) an exponentially decaying potential. The Coulomb potential leads to positronium-like binding energies, with the ground state (<span><math><mi>n</mi><mo>=</mo><mn>0</mn></math></span>) energy approximately <span><math><msubsup><mrow><mi>E</mi></mrow><mrow><mi>n</mi></mrow><mrow><mi>b</mi></mrow></msubsup><mo>≈</mo><mo>−</mo><msub><mrow><mi>m</mi></mrow><mrow><mi>e</mi></mrow></msub><msup><mrow><mi>c</mi></mrow><mrow><mn>2</mn></mrow></msup><msup><mrow><mi>α</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>/</mo><mn>4</mn><mo>∼</mo><mo>−</mo><mn>6.803</mn></math></span> eV. On the other hand, the exponential potential establishes critical mass thresholds, <span><math><msub><mrow><mi>m</mi></mrow><mrow><mi>c</mi></mrow></msub><mo>=</mo><mfrac><mrow><mo>(</mo><mi>n</mi><mo>+</mo><mfrac><mrow><mn>1</mn></mrow><mrow><mn>2</mn></mrow></mfrac><mo>)</mo><mi>ħ</mi></mrow><mrow><mn>2</mn><msub><mrow><mi>λ</mi></mrow><mrow><mi>c</mi></mrow></msub><mi>c</mi></mrow></mfrac></math></span>, at which the energy approaches zero, causing the system to cease to exist over time. Stability is maintained when <span><math><mi>n</mi><mo>+</mo><mfrac><mrow><mn>1</mn></mrow><mrow><mn>2</mn></mrow></mfrac><mo>&lt;</mo><mn>2</mn></math></span>, resulting in oscillatory behavior, while <span><math><mi>n</mi><mo>+</mo><mfrac><mrow><mn>1</mn></mrow><mrow><mn>2</mn></mrow></mfrac><mo>&gt;</mo><mn>2</mn></math></span> leads to decay. The energy spectrum reveals essential features of the system, and the wave function reflects the influence of the wormhole's throat, shaping spatial configurations and probability distributions. This work enhances our understanding of quantum phenomena in curved spacetimes and establishes connections to condensed matter physics.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"862 ","pages":"Article 139313"},"PeriodicalIF":4.3,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395722","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":"Generalized uncertainty principle mimicking dynamical dark energy: Matter perturbations and gravitational wave data analysis","authors":"G.G. Luciano ,&nbsp;Y. Sekhmani","doi":"10.1016/j.physletb.2025.139315","DOIUrl":"10.1016/j.physletb.2025.139315","url":null,"abstract":"<div><div>The Generalized Uncertainty Principle (GUP) stands out as a nearly ubiquitous feature in quantum gravity modeling, predicting the emergence of a minimum length at the Planck scale. Recently, it has been shown to modify the area-law scaling of the Bekenstein-Hawking entropy, giving rise to deformed Friedmann equations within Jacobson's approach. The ensuing model incorporates the GUP correction as a quintessence-like dark energy that supplements the cosmological constant, influencing the dynamics of the early Universe while aligning with the ΛCDM paradigm in the current epoch. In this extended scenario, we examine the growth of matter perturbations and structure formation employing the Top-Hat Spherical Collapse approach. Our analysis reveals that the profile of the density contrast is sensitive to the GUP parameter <em>β</em>, resulting in a slower gravitational evolution of primordial fluctuations in the matter density. We also discuss implications for the relic density of Primordial Gravitational Waves (PGWs), identifying the parameter space that enhances the PGW spectrum. Using the sensitivity of the next-generation GW observatories in the frequency range below <span><math><msup><mrow><mn>10</mn></mrow><mrow><mn>3</mn></mrow></msup><mspace></mspace><mrow><mi>Hz</mi></mrow></math></span>, we constrain <span><math><mi>β</mi><mo>≲</mo><msup><mrow><mn>10</mn></mrow><mrow><mn>39</mn></mrow></msup></math></span>, which is more stringent than most other cosmological/astrophysical limits. This finding highlights the potential role of GWs in the pursuit of understanding quantum gravity phenomenology.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"862 ","pages":"Article 139315"},"PeriodicalIF":4.3,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395738","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":"Entanglement of purification as a measure of non-conformality","authors":"M. Asadi","doi":"10.1016/j.physletb.2025.139312","DOIUrl":"10.1016/j.physletb.2025.139312","url":null,"abstract":"<div><div>We have studied the entanglement of purification <span><math><msub><mrow><mi>E</mi></mrow><mrow><mi>p</mi></mrow></msub></math></span> in a non-conformal holographic model which is a five-dimensional Einstein gravity coupled to a scalar field <em>ϕ</em> with a non-trivial potential <span><math><mi>V</mi><mo>(</mo><mi>ϕ</mi><mo>)</mo></math></span>. The dual 4-dimensional gauge theory is not conformal and exhibits a RG flow between two different fixed points. There are three parameters including energy scale Λ, model parameter <span><math><msub><mrow><mi>ϕ</mi></mrow><mrow><mi>M</mi></mrow></msub></math></span> and temperature <em>T</em> which control the behaviour of the theory. Interestingly, we have found that <span><math><msub><mrow><mi>E</mi></mrow><mrow><mi>p</mi></mrow></msub></math></span> can be used as a measure to probe the non-conformal behaviour of the theory at both zero and finite temperature. Furthermore, we have found that if one consider two different mixed state characterized by distinct values of <span><math><mfrac><mrow><mi>Λ</mi></mrow><mrow><mi>T</mi></mrow></mfrac></math></span>, then the correlation between the subsystems of these states can be the same independent of <span><math><mfrac><mrow><mi>Λ</mi></mrow><mrow><mi>T</mi></mrow></mfrac></math></span>.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"862 ","pages":"Article 139312"},"PeriodicalIF":4.3,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143388182","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":"Hadronic top quark polarimetry with ParticleNet","authors":"Zhongtian Dong ,&nbsp;Dorival Gonçalves ,&nbsp;Kyoungchul Kong ,&nbsp;Andrew J. Larkoski ,&nbsp;Alberto Navarro","doi":"10.1016/j.physletb.2025.139314","DOIUrl":"10.1016/j.physletb.2025.139314","url":null,"abstract":"<div><div>Precision studies for top quark physics are a cornerstone of the Large Hadron Collider program. Polarization, probed through decay kinematics, provides a unique tool to scrutinize the top quark across its various production modes and to explore potential new physics effects. However, the top quark most often decays hadronically, for which unambiguous identification of its decay products sensitive to top quark polarization is not possible. In this Letter, we introduce a jet flavor tagging method to significantly improve spin analyzing power in hadronic decays, going beyond exclusive kinematic information employed in previous studies. We provide parametric estimates of the improvement from flavor tagging with any set of measured observables and demonstrate this in practice on simulated data using a Graph Neural Network (GNN). We find that the spin analyzing power in hadronic decays can improve by approximately 20% (40%) compared to the kinematic approach, assuming an efficiency of 0.5 (0.2) for the network.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"862 ","pages":"Article 139314"},"PeriodicalIF":4.3,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395736","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":"New black hole solutions in f(P) gravity and their thermodynamic nature","authors":"Aniruddha Ghosh,&nbsp;Ujjal Debnath","doi":"10.1016/j.physletb.2025.139305","DOIUrl":"10.1016/j.physletb.2025.139305","url":null,"abstract":"<div><div>Black holes are the fascinating objects in the universe. They represent extreme deformations in spacetime geometry. Here, we construct <span><math><mi>f</mi><mo>(</mo><mi>P</mi><mo>)</mo></math></span> gravity and the first example of static-spherically symmetric black hole solution in <span><math><mi>f</mi><mo>(</mo><mi>P</mi><mo>)</mo></math></span> gravity and discuss their thermodynamics. Using the numerical approach and series solution, we discover the solution and demonstrate that it is a generalization of Schwarzschild. The solution is characterized by a single function that satisfies a non-linear fourth-order differential equation. Interestingly, we can analytically calculate the solution's specific heat, Wald entropy, and Hawking temperature as a function of horizon radius. After analyzing the specific heat, we discovered that the black hole is thermodynamically stable over a small horizon radius.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"862 ","pages":"Article 139305"},"PeriodicalIF":4.3,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143418548","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":"Percolation of domain walls in the two-Higgs doublet model","authors":"Richard A. Battye,&nbsp;Steven J. Cotterill,&nbsp;Eva Sabater Andres,&nbsp;Adam K. Thomasson","doi":"10.1016/j.physletb.2025.139311","DOIUrl":"10.1016/j.physletb.2025.139311","url":null,"abstract":"<div><div>Domain walls formed during a phase transition in a simple field theory model with <span><math><msub><mrow><mi>Z</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span> symmetry in a periodic box have been demonstrated to annihilate as fast as causality allows and their area density scales <span><math><mo>∝</mo><msup><mrow><mi>t</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></math></span>. We have performed numerical simulations of the dynamics of domain walls in the Two-Higgs Doublet Model (2HDM) where the potential has <span><math><msub><mrow><mi>Z</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span> symmetry in two spatial dimensions. We observed significant differences with the standard case. Although the extreme long-time limit is the same for the <span><math><mo>≈</mo><msup><mrow><mn>10</mn></mrow><mrow><mn>5</mn></mrow></msup></math></span> sets of random initial configurations analyzed, the percolation process is much slower due to the formation of long-lived loops. We suggest that this is due to the build up of superconducting currents on the walls which could lead ultimately to stationary configurations known as Kinky Vortons. We discuss the relevance of these findings for the production of Vortons in three spatial dimensions.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"862 ","pages":"Article 139311"},"PeriodicalIF":4.3,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143388150","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}