Physics Letters B最新文献

{"title":"Two- versus three-body approach to femtoscopic hadron-deuteron correlations","authors":"Stanisław Mrówczyński","doi":"10.1016/j.physletb.2025.139413","DOIUrl":"10.1016/j.physletb.2025.139413","url":null,"abstract":"<div><div>The three-body approach to hadron-deuteron correlations is shown to turn into a two-body approach if the three-particle hadron-deuteron wave function factorizes into the deuteron wave-function and the wave function of a hadron motion relative to the deuteron. Then, the hadron-deuteron correlation function is as in the two-body approach only the source radius somewhat changes. For this reason, as we argue, the two-body approach works well for kaon-deuteron correlations but it fails for proton-deuteron ones in case of small sources. Applying the three-body approach generalized to the case where the radius of the hadron source is different from the nucleon source radius, we derive the source radius formula which used in the two-body approach gives the correlation function as in the ‘factorized’ three-body one. The formula is discussed in the context of existing and future experimental data.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"864 ","pages":"Article 139413"},"PeriodicalIF":4.3,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687982","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":"Angular analysis of the B0 → K⁎(892)0μ+μ− decay in proton-proton collisions at s=13TeV","authors":"","doi":"10.1016/j.physletb.2025.139406","DOIUrl":"10.1016/j.physletb.2025.139406","url":null,"abstract":"<div><div>A full set of optimized observables is measured in an angular analysis of the decay <span><math><msup><mrow><mi>B</mi></mrow><mrow><mn>0</mn></mrow></msup><mo>→</mo><msup><mrow><mi>K</mi></mrow><mrow><mo>⁎</mo></mrow></msup><msup><mrow><mo>(</mo><mn>892</mn><mo>)</mo></mrow><mrow><mn>0</mn></mrow></msup><msup><mrow><mi>μ</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>μ</mi></mrow><mrow><mo>−</mo></mrow></msup></math></span> using a sample of proton-proton collisions at <span><math><msqrt><mrow><mi>s</mi></mrow></msqrt><mo>=</mo><mn>13</mn><mspace></mspace><mtext>TeV</mtext></math></span>, collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 140<!--> <span><math><msup><mrow><mtext>fb</mtext></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></math></span>. The analysis is performed in six bins of the squared invariant mass of the dimuon system, <span><math><msup><mrow><mi>q</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span>, over the range <span><math><mn>1.1</mn><mo>&lt;</mo><msup><mrow><mi>q</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>&lt;</mo><mn>16</mn><mspace></mspace><msup><mrow><mtext>GeV</mtext></mrow><mrow><mn>2</mn></mrow></msup></math></span>. The results are among the most precise experimental measurements of the angular observables for this decay and are compared to a variety of predictions based on the standard model. Some of these predictions exhibit tension with the measurements.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"864 ","pages":"Article 139406"},"PeriodicalIF":4.3,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143716341","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":"Carroll–Field–Jackiw term in a massless Rarita-Schwinger model","authors":"M. Gomes ,&nbsp;J.G. Lima ,&nbsp;T. Mariz ,&nbsp;J.R. Nascimento ,&nbsp;A.Yu. Petrov","doi":"10.1016/j.physletb.2025.139408","DOIUrl":"10.1016/j.physletb.2025.139408","url":null,"abstract":"<div><div>We consider the massless Rarita-Schwinger (RS) LV QED. In this theory, we introduce the gauge fixing to obtain the propagator for the RS field, and calculate the Carroll-Field-Jackiw term, which turns out to be finite and ambiguous, and only in one calculation scheme, based on the nonlinear gauge framework, the gauge independence of the result is achieved.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"864 ","pages":"Article 139408"},"PeriodicalIF":4.3,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687938","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 background for thermal photons in heavy ion collisions","authors":"Satya Ranjan Nayak ,&nbsp;Gauri Devi ,&nbsp;B.K. Singh","doi":"10.1016/j.physletb.2025.139410","DOIUrl":"10.1016/j.physletb.2025.139410","url":null,"abstract":"<div><div>In this work, we present the transverse momentum spectra of prompt and decay photons in Au-Au collisions for <span><math><msqrt><mrow><msub><mrow><mi>s</mi></mrow><mrow><mi>N</mi><mi>N</mi></mrow></msub></mrow></msqrt><mo>=</mo></math></span> 200 GeV, 62.4 GeV, 39 GeV, and 27 GeV. The major sources of the photons in Angantyr include hard processes, Parton showers, and resonance decay. The multiparton interactions and hadronic rescatterings significantly increase the photon yield. The model shows a good match with the available experimental data at high <span><math><msub><mrow><mi>p</mi></mrow><mrow><mi>T</mi></mrow></msub></math></span>. The difference in yield at low <span><math><msub><mrow><mi>p</mi></mrow><mrow><mi>T</mi></mrow></msub></math></span> suggests that Quark Gluon Plasma of <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>e</mi><mi>f</mi><mi>f</mi></mrow></msub></math></span> = 0.167 GeV/c in central Au-Au collision at 200 GeV is formed, the new effective temperature is less than the ones extracted without removing background photons. At low <span><math><msub><mrow><mi>p</mi></mrow><mrow><mi>T</mi></mrow></msub></math></span> the decay photon spectra scales with <span><math><msup><mrow><mo>(</mo><mfrac><mrow><mi>d</mi><msub><mrow><mi>N</mi></mrow><mrow><mi>c</mi><mi>h</mi></mrow></msub></mrow><mrow><mi>d</mi><mi>η</mi></mrow></mfrac><mo>)</mo></mrow><mrow><mn>1.25</mn></mrow></msup></math></span>, the scaling is independent of collision energy and system size. The scaling no longer holds at high <span><math><msub><mrow><mi>p</mi></mrow><mrow><mi>T</mi></mrow></msub></math></span> and the spectra become beam energy dependent. The scaled <span><math><msub><mrow><mi>p</mi></mrow><mrow><mi>T</mi></mrow></msub></math></span> spectra of p-p and d-Au collisions show an opposite trend at high <span><math><msub><mrow><mi>p</mi></mrow><mrow><mi>T</mi></mrow></msub></math></span>, their scaled yield is greater than the Au-Au collision at the same energy.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"864 ","pages":"Article 139410"},"PeriodicalIF":4.3,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143696013","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":"Hidden charm-bottom structures bcb‾c‾: Axial-vector case","authors":"S.S. Agaev ,&nbsp;K. Azizi ,&nbsp;H. Sundu","doi":"10.1016/j.physletb.2025.139404","DOIUrl":"10.1016/j.physletb.2025.139404","url":null,"abstract":"<div><div>Mass and width of a hidden charm-bottom axial-vector structure <em>T</em> containing <span><math><mi>b</mi><mi>c</mi><mover><mrow><mi>b</mi></mrow><mo>‾</mo></mover><mover><mrow><mi>c</mi></mrow><mo>‾</mo></mover></math></span> quarks are calculated in QCD sum rule framework. It is treated as a diquark-antidiquark state built of scalar diquark and axial-vector antidiquark components. The mass of <em>T</em> is computed using the two-point sum rule method. The width of this particle is evaluated by considering eight decay modes: The decays to <span><math><msub><mrow><mi>η</mi></mrow><mrow><mi>b</mi></mrow></msub><mi>J</mi><mo>/</mo><mi>ψ</mi></math></span>, <span><math><msub><mrow><mi>η</mi></mrow><mrow><mi>c</mi></mrow></msub><mi>ϒ</mi><mo>(</mo><mn>1</mn><mi>S</mi><mo>)</mo></math></span>, <span><math><msubsup><mrow><mi>B</mi></mrow><mrow><mi>c</mi></mrow><mrow><mo>−</mo></mrow></msubsup><msubsup><mrow><mi>B</mi></mrow><mrow><mi>c</mi></mrow><mrow><mo>⁎</mo><mo>+</mo></mrow></msubsup></math></span>, and <span><math><msubsup><mrow><mi>B</mi></mrow><mrow><mi>c</mi></mrow><mrow><mo>+</mo></mrow></msubsup><msubsup><mrow><mi>B</mi></mrow><mrow><mi>c</mi></mrow><mrow><mo>⁎</mo><mo>−</mo></mrow></msubsup></math></span> are dissociation processes, in which all initial quarks are distributed between the final-state particles. The decays to <em>DD</em> and <em>BB</em> mesons with appropriate charges and spin-parities are channels generated due to the annihilations of <span><math><mi>b</mi><mover><mrow><mi>b</mi></mrow><mo>‾</mo></mover></math></span> and <span><math><mi>c</mi><mover><mrow><mi>c</mi></mrow><mo>‾</mo></mover></math></span> quarks from <em>T</em>. Partial widths for all of these processes are obtained by employing the three-point sum rule approach necessary to find the strong couplings at relevant tetraquark-meson-meson vertices. Our results for the mass <span><math><mi>m</mi><mo>=</mo><mo>(</mo><mn>12715</mn><mo>±</mo><mn>90</mn><mo>)</mo><mspace></mspace><mrow><mi>MeV</mi></mrow></math></span> and width <span><math><mi>Γ</mi><mo>[</mo><mi>T</mi><mo>]</mo><mo>=</mo><mo>(</mo><mn>140</mn><mo>±</mo><mn>13</mn><mo>)</mo><mspace></mspace><mrow><mi>MeV</mi></mrow></math></span> of the tetraquark <em>T</em>, as well as its numerous decay channels explored in this article are useful for ongoing and future experimental investigations of fully heavy resonances.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"864 ","pages":"Article 139404"},"PeriodicalIF":4.3,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143696016","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":"Identifying weak critical fluctuations of intermittency in heavy-ion collisions with topological machine learning","authors":"Rui Wang ,&nbsp;Chengrui Qiu ,&nbsp;Chuan-Shen Hu ,&nbsp;Zhiming Li ,&nbsp;Yuanfang Wu","doi":"10.1016/j.physletb.2025.139405","DOIUrl":"10.1016/j.physletb.2025.139405","url":null,"abstract":"<div><div>Large density fluctuations of conserved charges have been proposed as a promising signature for exploring the QCD critical point in heavy-ion collisions. These fluctuations are expected to exhibit a fractal or scale-invariant behavior, which can be probed by intermittency analysis. Recent high-energy experimental studies reveal that the signal of critical fluctuations related to intermittency is very weak and thus could be easily obscured by the overwhelming background particles in the data sample. Employing a point cloud neural network with topological machine learning, we can successfully classify weak signal events from background noise by the extracted distinct topological features, and accurately determine the intermittency index for weak signal event samples.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"864 ","pages":"Article 139405"},"PeriodicalIF":4.3,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687981","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 weak gravity conjecture in the Vilkovisky-DeWitt effective action of quantum gravity","authors":"Tommaso Antonelli,&nbsp;Xavier Calmet","doi":"10.1016/j.physletb.2025.139403","DOIUrl":"10.1016/j.physletb.2025.139403","url":null,"abstract":"<div><div>The Weak Gravity Conjecture states that in any consistent theory of quantum gravity in the landscape of string theory, the repulsive force mediated by a U(1) gauge field must be stronger than the attractive force of gravity. In this work, we calculate quantum gravitational corrections to the charge-to-mass ratio of extremal Reissner-Nordström black holes, using the Vilkovisky-deWitt unique effective action approach, since this ratio provides a discriminant to select low-energy effective theories of quantum gravity that fulfill the conjecture. We find that depending on the values of the Wilson coefficients of the effective action, some UV complete theories may fulfill the conjecture, while others may not.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"864 ","pages":"Article 139403"},"PeriodicalIF":4.3,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143644657","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":"Are regular black holes from pure gravity classified within the same thermodynamical topology?","authors":"Sheng-Wei Wang ,&nbsp;Shan-Ping Wu ,&nbsp;Shao-Wen Wei","doi":"10.1016/j.physletb.2025.139402","DOIUrl":"10.1016/j.physletb.2025.139402","url":null,"abstract":"<div><div>Regular black holes, which avoid the essential central singularities, can be constructed through various methods, including nonlinear electrodynamics and quantum corrections. Recently, it was shown that via an infinite tower of higher-curvature corrections, one can obtain different regular black hole solutions in any spacetime dimension <span><math><mi>D</mi><mo>≥</mo><mn>5</mn></math></span>. Utilizing the concept of thermodynamical topology, we examine these black holes as topological thermodynamic defects, classifying them into distinct topological categories based on their generalized free energy. We demonstrate that the Hawking temperature of the black hole has at least one zero point at the small horizon radius limit. Under this fact, the regular black holes generated through the purely gravitational theories exhibit universal thermodynamical behaviors, strongly suggesting they belong to the same topological class. We present a comprehensive analysis of these properties, providing a clearer understanding of the fundamental nature of this type of regular black holes and their classification within the framework of thermodynamical topology.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"864 ","pages":"Article 139402"},"PeriodicalIF":4.3,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143644660","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":"Unveiling neutrino mysteries with Δ(27) symmetry","authors":"Manash Dey,&nbsp;Subhankar Roy","doi":"10.1016/j.physletb.2025.139401","DOIUrl":"10.1016/j.physletb.2025.139401","url":null,"abstract":"<div><div>An elegant model for lepton masses and mixing is proposed in the light of both Type I and Type II seesaw mechanisms emphasizing the presence of discrete flavour symmetries <span><math><mi>Δ</mi><mo>(</mo><mn>27</mn><mo>)</mo></math></span>, <span><math><msub><mrow><mi>Z</mi></mrow><mrow><mn>3</mn></mrow></msub></math></span> and <span><math><msub><mrow><mi>Z</mi></mrow><mrow><mn>10</mn></mrow></msub></math></span>. The model marks a forbidden region in the experimental 3<em>σ</em> bound of the atmospheric mixing angle. In addition, it highlights a quasi-degenerate mass spectra within the normal hierarchy of neutrino masses and constrains the predictions of the Majorana phases. The model is testable through ongoing and future experiments on neutrinoless double beta (<span><math><mn>0</mn><mi>ν</mi><mi>β</mi><mi>β</mi></math></span>) decay and charged lepton flavour violation (cLFV).</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"864 ","pages":"Article 139401"},"PeriodicalIF":4.3,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687868","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":"On the origin of the peak of the sound velocity for isospin imbalanced strongly interacting matter","authors":"Alejandro Ayala ,&nbsp;Bruno S. Lopes ,&nbsp;Ricardo L.S. Farias ,&nbsp;Luis C. Parra","doi":"10.1016/j.physletb.2025.139396","DOIUrl":"10.1016/j.physletb.2025.139396","url":null,"abstract":"<div><div>We study the properties of a system composed of strongly interacting matter with an isospin imbalance, using as an effective description of QCD the two-flavor Linear Sigma Model with quarks. From the one-loop effective potential, including the two light quarks, pions and sigma contributions, and enforcing the restrictions imposed by chiral symmetry, we show that the development of an isospin condensate comes together with the emergence of a Goldstone mode that provides a constraint for the chiral and isospin condensates as a result of a non-trivial mixing between the charged pions and the sigma. We compute the thermodynamical quantities of interest and in particular the sound velocity squared, showing that it presents a maximum for an isospin chemical potential similar to the one reported by lattice QCD results and also with a similar height. Therefore, we attribute the origin of the peak of the sound velocity to the proper treatment of the Goldstone mode and to the non-trivial mixing of the charged pions and sigma in the isospin condensed phase.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"864 ","pages":"Article 139396"},"PeriodicalIF":4.3,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687867","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}