Physical Review D最新文献

{"title":"Finite width effects in nonleptonic D -meson decays","authors":"Girish Kumar, Sudheer Muhammad, Alexey A. Petrov","doi":"10.1103/physrevd.111.054038","DOIUrl":"https://doi.org/10.1103/physrevd.111.054038","url":null,"abstract":"Many analyses of two-body nonleptonic decays of D</a:mi></a:math>-mesons rely on flavor <c:math xmlns:c=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><c:mi>S</c:mi><c:mi>U</c:mi><c:mo stretchy=\"false\">(</c:mo><c:mn>3</c:mn><c:mo stretchy=\"false\">)</c:mo></c:math> symmetry relations and fits of experimental data of decays rates to extract the universal transition amplitudes. Such fits assume that the final state mesons are well-defined asymptotic states of QCD. We develop a technique to take into account the finite width effects of the final state mesons and study their effects on the extracted values of transition amplitudes. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20167,"journal":{"name":"Physical Review D","volume":"36 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143736691","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":"Ensembles of center vortices and chains: Insights from a natural lattice framework","authors":"David R. Junior, Luis E. Oxman","doi":"10.1103/physrevd.111.054036","DOIUrl":"https://doi.org/10.1103/physrevd.111.054036","url":null,"abstract":"A scenario to understand the asymptotic properties of confinement between quark probes, based on a 4D mixed ensemble of percolating center-vortex world surfaces and chains, was initially proposed by one of us in a non-Abelian setting. More recently, the same physics was reobtained by means of a Schrödinger wave functional peaked at Abelian-projected configurations, which deals with center-vortex lines and pointlike monopoles in real space. In this work, we formulate the Abelian-projected ensemble and reassess the non-Abelian one within the Weingarten lattice representation for the sum over surfaces. In the phase where world surfaces are stabilized by contact interactions and percolate, lattice gauge fields emerge. This generalizes the Goldstone modes in an Abelian loop condensate to the case where non-Abelian degrees of freedom are present. In this language, the different natural matching properties of elementary center-vortex world surfaces and monopole worldlines can be easily characterized. In the lattice, the Abelian setting also implements the original idea that the mixed ensemble reconciles N</a:mi></a:mrow></a:math>-ality with the formation of a confining flux tube. In this picture, center vortices and chains explain why Abelian-projected variables capture this property at asymptotic distances while simultaneously allowing for a “dual superconductor” description of the fundamental string. Common features, differences in the continuum, and perspectives will also be addressed. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20167,"journal":{"name":"Physical Review D","volume":"1 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143744763","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":"First-order electroweak phase transition with a gauge-invariant approach","authors":"Renhui Qin, Ligong Bian","doi":"10.1103/physrevd.111.l051702","DOIUrl":"https://doi.org/10.1103/physrevd.111.l051702","url":null,"abstract":"We study the electroweak phase transition with a three-dimensional standard model effective field theory at the two-loop level under a gauge-invariant approach. We observe that the phase transition parameters obtained with the gauge-invariant approach deviate from that obtained in the Landau gauge at around the percent level. We give the strongly first-order phase transition condition for electroweak baryogenesis and find that the predicted gravitational wave signals would be reduced for the new physics scale Λ</a:mi>≲</a:mo>590</a:mn></a:mtext></a:mtext>GeV</a:mi></a:math>, and the parameter spaces of <d:math xmlns:d=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><d:mi mathvariant=\"normal\">Λ</d:mi><d:mo>≲</d:mo><d:mn>570</d:mn><d:mtext> </d:mtext><d:mtext> </d:mtext><d:mi>GeV</d:mi></d:math> can be probed by the space-based interferometers, such as LISA, TianQin, and Taiji. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20167,"journal":{"name":"Physical Review D","volume":"12 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143744766","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":"Cosmological simulation of axion-Higgs strings: Gravitational waves and dark matter","authors":"Yongtao Jia, Ligong Bian","doi":"10.1103/physrevd.111.063552","DOIUrl":"https://doi.org/10.1103/physrevd.111.063552","url":null,"abstract":"Axions have long been considered plausible candidates for dark matter. The axion dark matter emitted from cosmic strings after the Peccei-Quinn (PQ) symmetry breaking in the early Universe was extensively simulated. In this work, we study dark matter and gravitational waves through the lattice simulation of the axion-Higgs string. We gave the dark matter overproduction and the big bang nucleosynthesis bounds on the axion decay constant f</a:mi>a</a:mi></a:msub></a:math> and the axion mass <c:math xmlns:c=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><c:msub><c:mi>m</c:mi><c:mi>a</c:mi></c:msub></c:math> for axionlike particles, and found that the predicted gravitational wave spectra cannot be probed by the dataset of the current pulsar timing array experiments. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20167,"journal":{"name":"Physical Review D","volume":"73 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143744768","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":"Dark matter ultraviolet freeze-in in general reheating scenarios","authors":"Nicolás Bernal, Kuldeep Deka, Marta Losada","doi":"10.1103/physrevd.111.055034","DOIUrl":"https://doi.org/10.1103/physrevd.111.055034","url":null,"abstract":"The dynamics of cosmic reheating, that is, on how the energy stored in the inflaton is transferred to the standard model (SM) thermal bath, is largely unknown. In this work, we show that the phenomenology of the nonbaryonic dark matter (DM) ultraviolet freeze-in production strongly depends on the dynamics of the cosmic-reheating era. Using a general parametrization for the Hubble expansion rate, and SM temperature, we thoroughly investigate DM production during reheating, not only recovering earlier findings that focused on specific cases but also exploring alternative scenarios. Additionally, we derive a generalized framework for DM production via inflaton decays and identify the viable parameter space, while simultaneously addressing constraints from cosmic microwave background observations. As illustrative examples, we explore gravitational DM production through scatterings of SM particles or inflatons, deriving well-defined parameter regions for these scenarios. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20167,"journal":{"name":"Physical Review D","volume":"183 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143744896","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":"Analysis of the B(s)→T(JP=2−) transition in light cone QCD sum rules","authors":"T. M. Aliev, Y. Sarac","doi":"10.1103/physrevd.111.056028","DOIUrl":"https://doi.org/10.1103/physrevd.111.056028","url":null,"abstract":"The semileptonic B</a:mi></a:mrow>(</a:mo>s</a:mi>)</a:mo></a:mrow></a:msub>→</a:mo>T</a:mi>(</a:mo>J</a:mi></a:mrow>P</a:mi></a:mrow></a:msup>=</a:mo>2</a:mn></a:mrow>−</a:mo></a:mrow></a:msup>)</a:mo>l</a:mi></a:mrow>+</a:mo></a:mrow></a:msup>l</a:mi></a:mrow>−</a:mo></a:mrow></a:msup></a:mrow></a:math> decays induced by flavor changing neural currents are investigated within the light cone quantum chromodynamics (QCD) sum rule method in the leading order of <h:math xmlns:h=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><h:mi>O</h:mi><h:mo stretchy=\"false\">(</h:mo><h:msub><h:mi>α</h:mi><h:mi>s</h:mi></h:msub><h:mo stretchy=\"false\">)</h:mo></h:math>. We apply the <l:math xmlns:l=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><l:mi>B</l:mi></l:math> meson distribution amplitudes up to twist-4 and calculate the relevant form factors of the <n:math xmlns:n=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><n:msub><n:mi>B</n:mi><n:mrow><n:mo stretchy=\"false\">(</n:mo><n:mi>s</n:mi><n:mo stretchy=\"false\">)</n:mo></n:mrow></n:msub><n:mo stretchy=\"false\">→</n:mo><n:mi>T</n:mi></n:math> transitions, where <s:math xmlns:s=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><s:mrow><s:mi>T</s:mi><s:mo>=</s:mo><s:msub><s:mrow><s:mi>K</s:mi></s:mrow><s:mrow><s:mn>2</s:mn></s:mrow></s:msub><s:mo>,</s:mo><s:msub><s:mrow><s:mi>a</s:mi></s:mrow><s:mrow><s:mn>2</s:mn></s:mrow></s:msub><s:mo>,</s:mo><s:msub><s:mrow><s:mi>f</s:mi></s:mrow><s:mrow><s:mn>2</s:mn></s:mrow></s:msub><s:mo>,</s:mo><s:msub><s:mrow><s:mi>ϕ</s:mi></s:mrow><s:mrow><s:mn>2</s:mn></s:mrow></s:msub></s:mrow></s:math> with <u:math xmlns:u=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><u:msup><u:mi>J</u:mi><u:mi>P</u:mi></u:msup><u:mo>=</u:mo><u:msup><u:mn>2</u:mn><u:mo>−</u:mo></u:msup></u:math>. The obtained results of the form factors then adopted in the calculations of the corresponding widths. The present results can be used in future experiments for studying the properties of <w:math xmlns:w=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><w:msup><w:mi>J</w:mi><w:mi>P</w:mi></w:msup><w:mo>=</w:mo><w:msup><w:mn>2</w:mn><w:mo>−</w:mo></w:msup></w:math> tensor mesons. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20167,"journal":{"name":"Physical Review D","volume":"75 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143744765","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":"Novel approach to probing top-philic resonances with boosted four-top tagging","authors":"Luc Darmé, Benjamin Fuks, Hao-Lin Li, Matteo Maltoni, Olivier Mattelaer, Julien Touchèque","doi":"10.1103/physrevd.111.055037","DOIUrl":"https://doi.org/10.1103/physrevd.111.055037","url":null,"abstract":"We introduce a novel search strategy for heavy top-philic resonances that induce new contributions to four-top production at the LHC. We capitalize on recent advances in top-tagging performance to demonstrate that the final state, that is expected to be boosted based on current limits, can be fully reconstructed and exploited. Notably, our approach promises bounds on new physics cross sections that are a few to 60 times stronger than those obtained with existing searches, showcasing its unprecedented effectiveness in probing top-philic new physics. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20167,"journal":{"name":"Physical Review D","volume":"11 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143736683","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":"Longitudinal leading-twist distribution amplitude of the P11 -state b1(1235) meson and its implications on B→b1(1235)ℓ+νℓ decays","authors":"Long Zeng, Xing-Gang Wu, Dan-Dan Hu, Hai-Bing Fu, Tao Zhong","doi":"10.1103/physrevd.111.056030","DOIUrl":"https://doi.org/10.1103/physrevd.111.056030","url":null,"abstract":"In the paper, we derive the ξ&lt;/a:mi&gt;&lt;/a:math&gt; moments &lt;c:math xmlns:c=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"&gt;&lt;c:mo stretchy=\"false\"&gt;⟨&lt;/c:mo&gt;&lt;c:msubsup&gt;&lt;c:mi&gt;ξ&lt;/c:mi&gt;&lt;c:mrow&gt;&lt;c:mn&gt;2&lt;/c:mn&gt;&lt;c:mo&gt;;&lt;/c:mo&gt;&lt;c:msub&gt;&lt;c:mi&gt;b&lt;/c:mi&gt;&lt;c:mn&gt;1&lt;/c:mn&gt;&lt;/c:msub&gt;&lt;/c:mrow&gt;&lt;c:mrow&gt;&lt;c:mi&gt;n&lt;/c:mi&gt;&lt;c:mo&gt;;&lt;/c:mo&gt;&lt;c:mo stretchy=\"false\"&gt;∥&lt;/c:mo&gt;&lt;/c:mrow&gt;&lt;/c:msubsup&gt;&lt;c:mo stretchy=\"false\"&gt;⟩&lt;/c:mo&gt;&lt;/c:math&gt; of the longitudinal leading-twist distribution amplitude &lt;h:math xmlns:h=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"&gt;&lt;h:msubsup&gt;&lt;h:mi&gt;ϕ&lt;/h:mi&gt;&lt;h:mrow&gt;&lt;h:mn&gt;2&lt;/h:mn&gt;&lt;h:mo&gt;;&lt;/h:mo&gt;&lt;h:msub&gt;&lt;h:mi&gt;b&lt;/h:mi&gt;&lt;h:mn&gt;1&lt;/h:mn&gt;&lt;/h:msub&gt;&lt;/h:mrow&gt;&lt;h:mo stretchy=\"false\"&gt;∥&lt;/h:mo&gt;&lt;/h:msubsup&gt;&lt;/h:math&gt; for the &lt;k:math xmlns:k=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"&gt;&lt;k:mrow&gt;&lt;k:mmultiscripts&gt;&lt;k:mrow&gt;&lt;k:msub&gt;&lt;k:mrow&gt;&lt;k:mi&gt;P&lt;/k:mi&gt;&lt;/k:mrow&gt;&lt;k:mrow&gt;&lt;k:mn&gt;1&lt;/k:mn&gt;&lt;/k:mrow&gt;&lt;/k:msub&gt;&lt;/k:mrow&gt;&lt;k:mprescripts/&gt;&lt;k:none/&gt;&lt;k:mrow&gt;&lt;k:mn&gt;1&lt;/k:mn&gt;&lt;/k:mrow&gt;&lt;/k:mmultiscripts&gt;&lt;/k:mrow&gt;&lt;/k:math&gt;-state &lt;m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"&gt;&lt;m:msub&gt;&lt;m:mi&gt;b&lt;/m:mi&gt;&lt;m:mn&gt;1&lt;/m:mn&gt;&lt;/m:msub&gt;&lt;m:mo stretchy=\"false\"&gt;(&lt;/m:mo&gt;&lt;m:mn&gt;1235&lt;/m:mn&gt;&lt;m:mo stretchy=\"false\"&gt;)&lt;/m:mo&gt;&lt;/m:math&gt; meson by using the QCD sum rules under the background field theory. Considering the contributions from the vacuum condensates up to dimension six, its first two nonzero &lt;q:math xmlns:q=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"&gt;&lt;q:mi&gt;ξ&lt;/q:mi&gt;&lt;/q:math&gt; moments at the scale 1 GeV are &lt;s:math xmlns:s=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"&gt;&lt;s:mo stretchy=\"false\"&gt;⟨&lt;/s:mo&gt;&lt;s:msubsup&gt;&lt;s:mi&gt;ξ&lt;/s:mi&gt;&lt;s:mrow&gt;&lt;s:mn&gt;2&lt;/s:mn&gt;&lt;s:mo&gt;;&lt;/s:mo&gt;&lt;s:msub&gt;&lt;s:mi&gt;b&lt;/s:mi&gt;&lt;s:mn&gt;1&lt;/s:mn&gt;&lt;/s:msub&gt;&lt;/s:mrow&gt;&lt;s:mrow&gt;&lt;s:mn&gt;1&lt;/s:mn&gt;&lt;s:mo&gt;;&lt;/s:mo&gt;&lt;s:mo stretchy=\"false\"&gt;∥&lt;/s:mo&gt;&lt;/s:mrow&gt;&lt;/s:msubsup&gt;&lt;s:mo stretchy=\"false\"&gt;⟩&lt;/s:mo&gt;&lt;s:mo&gt;=&lt;/s:mo&gt;&lt;s:mo&gt;−&lt;/s:mo&gt;&lt;s:mn&gt;0.64&lt;/s:mn&gt;&lt;s:msubsup&gt;&lt;s:mn&gt;7&lt;/s:mn&gt;&lt;s:mrow&gt;&lt;s:mo&gt;−&lt;/s:mo&gt;&lt;s:mn&gt;0.113&lt;/s:mn&gt;&lt;/s:mrow&gt;&lt;s:mrow&gt;&lt;s:mo&gt;+&lt;/s:mo&gt;&lt;s:mn&gt;0.118&lt;/s:mn&gt;&lt;/s:mrow&gt;&lt;/s:msubsup&gt;&lt;/s:math&gt; and &lt;x:math xmlns:x=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"&gt;&lt;x:mo stretchy=\"false\"&gt;⟨&lt;/x:mo&gt;&lt;x:msubsup&gt;&lt;x:mi&gt;ξ&lt;/x:mi&gt;&lt;x:mrow&gt;&lt;x:mn&gt;2&lt;/x:mn&gt;&lt;x:mo&gt;;&lt;/x:mo&gt;&lt;x:msub&gt;&lt;x:mi&gt;b&lt;/x:mi&gt;&lt;x:mn&gt;1&lt;/x:mn&gt;&lt;/x:msub&gt;&lt;/x:mrow&gt;&lt;x:mrow&gt;&lt;x:mn&gt;3&lt;/x:mn&gt;&lt;x:mo&gt;;&lt;/x:mo&gt;&lt;x:mo stretchy=\"false\"&gt;∥&lt;/x:mo&gt;&lt;/x:mrow&gt;&lt;/x:msubsup&gt;&lt;x:mo stretchy=\"false\"&gt;⟩&lt;/x:mo&gt;&lt;x:mo&gt;=&lt;/x:mo&gt;&lt;x:mo&gt;−&lt;/x:mo&gt;&lt;x:mn&gt;0.32&lt;/x:mn&gt;&lt;x:msubsup&gt;&lt;x:mn&gt;8&lt;/x:mn&gt;&lt;x:mrow&gt;&lt;x:mo&gt;−&lt;/x:mo&gt;&lt;x:mn&gt;0.052&lt;/x:mn&gt;&lt;/x:mrow&gt;&lt;x:mrow&gt;&lt;x:mo&gt;+&lt;/x:mo&gt;&lt;x:mn&gt;0.055&lt;/x:mn&gt;&lt;/x:mrow&gt;&lt;/x:msubsup&gt;&lt;/x:math&gt;, respectively. Using those moments, we then fix the Gegenbauer expansion series of &lt;cb:math xmlns:cb=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"&gt;&lt;cb:msubsup&gt;&lt;cb:mi&gt;ϕ&lt;/cb:mi&gt;&lt;cb:mrow&gt;&lt;cb:mn&gt;2&lt;/cb:mn&gt;&lt;cb:mo&gt;;&lt;/cb:mo&gt;&lt;cb:msub&gt;&lt;cb:mi&gt;b&lt;/cb:mi&gt;&lt;cb:mn&gt;1&lt;/cb:mn&gt;&lt;/cb:msub&gt;&lt;/cb:mrow&gt;&lt;cb:mo stretchy=\"false\"&gt;∥&lt;/cb:mo&gt;&lt;/cb:msubsup&gt;&lt;/cb:math&gt; and apply it to calculate &lt;fb:math xmlns:fb=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"&gt;&lt;fb:mi&gt;B&lt;/fb:mi&gt;","PeriodicalId":20167,"journal":{"name":"Physical Review D","volume":"42 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143736687","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":"Machine learning-based detection of nonaxisymmetric fast neutrino flavor instabilities in core-collapse supernovae","authors":"Sajad Abbar, Akira Harada, Hiroki Nagakura","doi":"10.1103/physrevd.111.063077","DOIUrl":"https://doi.org/10.1103/physrevd.111.063077","url":null,"abstract":"In dense neutrino environments like core-collapse supernovae (CCSNe) and neutron star mergers, neutrinos can undergo fast flavor conversions when their angular distribution of neutrino electron lepton number (ν</a:mi>ELN</a:mi></a:math>) crosses zero along some directions. While previous studies have demonstrated the detection of axisymmetric <c:math xmlns:c=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><c:mi>ν</c:mi><c:mi>ELN</c:mi></c:math> crossings in these extreme environments, nonaxisymmetric crossings have remained elusive, mostly due to the absence of models for their angular distributions. In this study, we present a pioneering analysis of the detection of nonaxisymmetric <e:math xmlns:e=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><e:mi>ν</e:mi><e:mi>ELN</e:mi></e:math> crossings using machine learning (ML) techniques. Our ML models are trained on data from two CCSN simulations, one with rotation and one without, where nonaxisymmetric features in neutrino angular distributions play a crucial role. We demonstrate that our ML models achieve detection accuracies exceeding 90%. This is an important improvement, especially considering that a significant portion of <g:math xmlns:g=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><g:mi>ν</g:mi><g:mi>ELN</g:mi></g:math> crossings in these models eluded detection by earlier methods. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20167,"journal":{"name":"Physical Review D","volume":"183 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143736696","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":"Dynamical cosmological constant","authors":"G. di Donato, L. Pilo","doi":"10.1103/physrevd.111.064081","DOIUrl":"https://doi.org/10.1103/physrevd.111.064081","url":null,"abstract":"The dynamical realization of the equation of state p</a:mi>+</a:mo>ρ</a:mi>=</a:mo>0</a:mn></a:math> is studied. A nonpathological dynamics for the perturbations of such a system mimicking a dynamical cosmological constant (DCC) requires to go beyond the perfect fluid paradigm. It is shown that an anisotropic stress must be always present. The Hamiltonian of the system in isolation resembles the one of a Pais-Uhlenbeck oscillator and linear stability requires that it cannot be positive definite. The dynamics of linear cosmological perturbations in a DCC dominated Universe is studied in detail showing that when DCC is minimally coupled to gravity no dramatic instability is present. In contrast to what happens in a cosmological constant dominated Universe, the nonrelativistic matter contrast is no longer constant and exhibits an oscillator behavior at small scales while it grows weakly at large scales. In the gravitational waves sector, at small scales, the amplitude is still suppressed as the inverse power of the scale factor while it grows logarithmically at large scales. Also the vector modes propagate, though no growing mode is found. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20167,"journal":{"name":"Physical Review D","volume":"103 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143744897","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}