M. Costa, D. Gavriel, H. Panagopoulos, G. Spanoudes
{"title":"Perturbative determination of O(am) improvement on the QCD running coupling","authors":"M. Costa, D. Gavriel, H. Panagopoulos, G. Spanoudes","doi":"10.1103/yyvs-6q5v","DOIUrl":"https://doi.org/10.1103/yyvs-6q5v","url":null,"abstract":"We present the perturbative results of the discretization errors proportional to the quark mass [O</a:mi>(</a:mo>a</a:mi>m</a:mi>)</a:mo></a:math>] on the QCD running coupling within lattice perturbation theory. Our analysis involves calculating the two-loop renormalization factor <f:math xmlns:f=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><f:msub><f:mi>Z</f:mi><f:mi>g</f:mi></f:msub></f:math> using improved lattice actions for the <h:math xmlns:h=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><h:mi>S</h:mi><h:mi>U</h:mi><h:mo stretchy=\"false\">(</h:mo><h:msub><h:mi>N</h:mi><h:mi>c</h:mi></h:msub><h:mo stretchy=\"false\">)</h:mo></h:math> gauge group and <l:math xmlns:l=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><l:msub><l:mi>N</l:mi><l:mi>f</l:mi></l:msub></l:math> multiplets of fermions with a finite quark mass. We employ the background field method to compute <n:math xmlns:n=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><n:msub><n:mi>Z</n:mi><n:mi>g</n:mi></n:msub></n:math>, by calculating quantum corrections on both the background and quantum gluon propagator, respecting the <p:math xmlns:p=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><p:mi mathvariant=\"script\">O</p:mi><p:mo stretchy=\"false\">(</p:mo><p:mi>a</p:mi><p:mo stretchy=\"false\">)</p:mo></p:math> improvement. This allows us to evaluate the perturbative <u:math xmlns:u=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><u:mi mathvariant=\"script\">O</u:mi><u:mo stretchy=\"false\">(</u:mo><u:mi>a</u:mi><u:mi>m</u:mi><u:mo stretchy=\"false\">)</u:mo></u:math> lattice errors which affect the determination of the running coupling. Eliminating these <z:math xmlns:z=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><z:mi mathvariant=\"script\">O</z:mi><z:mo stretchy=\"false\">(</z:mo><z:mi>a</z:mi><z:mi>m</z:mi><z:mo stretchy=\"false\">)</z:mo></z:math> effects is crucial for the nonperturbative studies of precision determinations of the strong coupling constant using lattice field theory.","PeriodicalId":20167,"journal":{"name":"Physical Review D","volume":"27 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2025-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145311277","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":"Enhancing Taiji’s parameter estimation under nonstationarity: A time-frequency domain framework for Galactic binaries and instrumental noises","authors":"Minghui Du, Ziren Luo, Peng Xu","doi":"10.1103/gpmh-1hqx","DOIUrl":"https://doi.org/10.1103/gpmh-1hqx","url":null,"abstract":"","PeriodicalId":20167,"journal":{"name":"Physical Review D","volume":"22 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2025-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145311414","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":"Estimating energy levels from lattice QCD correlation functions using a transfer matrix formalism","authors":"Debsubhra Chakraborty, Dhruv Sood, Archana Radhakrishnan, Nilmani Mathur","doi":"10.1103/x3kb-8zw8","DOIUrl":"https://doi.org/10.1103/x3kb-8zw8","url":null,"abstract":"We present an efficient method for extracting energy levels from lattice QCD correlation functions by computing the eigenvalues of the transfer matrix associated with the lattice QCD Hamiltonian. While mathematically and numerically equivalent to the recently introduced Lanczos procedure [1], our approach introduces a novel prescription for removing spurious eigenvalues using a kernel density estimator and Gaussian-convoluted histogram method. This strategy yields a robust and stable estimate of the energy spectrum, outperforming the Cullum-Willoughby filtering technique in efficiency. In addition, we detail how this method can be applied to extract overlap factors from two-point correlation functions, as well as matrix elements from three-point functions with a current insertion. Furthermore, we extend the methodology to accommodate correlation matrices constructed from a variational basis of operators, with its block formulation. We demonstrate the efficacy of this framework by computing the two lowest energy levels for a broad range of hadrons, including several nuclei. Although the signal-to-noise ratio is not significantly improved, the extracted energy levels are found to be more reliable than those obtained with conventional techniques. Within a given statistical ensemble, the proposed method effectively captures both statistical uncertainties and systematic errors, including those arising from the choice of fitting window, making it a robust and practical tool for lattice QCD analysis.","PeriodicalId":20167,"journal":{"name":"Physical Review D","volume":"25 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2025-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145311431","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}
Sebastiano Bernuzzi, Joan Fontbuté, Simone Albanesi, An𝚤l Zenginoğlu
{"title":"Perturbative hyperboloidal extraction of gravitational waves in 3+1 numerical relativity","authors":"Sebastiano Bernuzzi, Joan Fontbuté, Simone Albanesi, An𝚤l Zenginoğlu","doi":"10.1103/g5cp-lzgw","DOIUrl":"https://doi.org/10.1103/g5cp-lzgw","url":null,"abstract":"We present a framework to propagate to null infinity gravitational waves computed at timelike world tubes in the interior of 3</a:mn>+</a:mo>1</a:mn></a:mrow></a:math> (Cauchy) numerical relativity simulations. In our method, numerical relativity data are used as the inner inflowing boundary of a perturbative time-domain Regge-Wheeler-Zerilli simulation in hyperboloidal coordinates that reaches null infinity. We showcase waveforms from <c:math xmlns:c=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><c:mrow><c:mo stretchy=\"false\">(</c:mo><c:mn>3</c:mn><c:mo>+</c:mo><c:mn>1</c:mn><c:mo stretchy=\"false\">)</c:mo><c:mi mathvariant=\"normal\">D</c:mi></c:mrow></c:math> simulations of gravitational collapse of rotating neutron stars, binary black hole mergers and scattering, and binary neutron star mergers and compare them to other extrapolation methods. Our perturbative hyperboloidal extraction provides a simple yet efficient procedure to compute gravitational waves with data quality comparable to the Cauchy-characteristic extraction for several practical applications. Nonlinear effects in the wave propagation are not captured by our method, but the present work is a stepping stone toward more sophisticated hyperboloidal schemes for gravitational-wave extraction.","PeriodicalId":20167,"journal":{"name":"Physical Review D","volume":"64 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2025-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145311419","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}
Alessandro Santini, Martina Muratore, Jonathan Gair, Olaf Hartwig
{"title":"Flexible, GPU-accelerated approach for the joint characterization of LISA instrumental noise and stochastic gravitational wave backgrounds","authors":"Alessandro Santini, Martina Muratore, Jonathan Gair, Olaf Hartwig","doi":"10.1103/csx9-9trp","DOIUrl":"https://doi.org/10.1103/csx9-9trp","url":null,"abstract":"LISA data analysis represents one of the most challenging tasks ahead for gravitational wave (GW) astronomy. Characterizing the instrument’s noise properties while fitting for all the other detectable sources is a key requirement of any robust inference pipeline. Noise estimation will also play a crucial role in searches and parameter estimation of cosmological and astrophysical stochastic signals. Previous studies have tackled this topic by assuming perfect knowledge of the spectral shape of the instrumental noise and of different possible types of stochastic GW backgrounds (SGWBs), usually resorting to parametrized templates. Recently, various works that employ template-agnostic methods have been presented. In this work, we take an additional step further, introducing flexible spectral shapes in both the instrumental noise and the stochastic signals. We account for the lack of knowledge of the exact shape of the individual contributions to the overall power spectral density by using splines to represent arbitrary perturbations of the noise and signal spectral densities. We implement a data-driven reversible jump Markov chain Monte Carlo algorithm to fit different components simultaneously and to infer the level of flexibility required under different scenarios. We test this approach on simulated LISA data produced under different assumptions. We investigate the impact of this increased flexibility on the reconstruction of both the injected signal and the noise level, and we discuss the prospects for claiming a successful SGWB detection.","PeriodicalId":20167,"journal":{"name":"Physical Review D","volume":"117 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2025-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145311432","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}
Dilip Kumar Ghosh, Biswarup Mukhopadhyaya, Sirshendu Samanta, Ritesh K. Singh
{"title":"Probing the low mass pseudoscalar in the flipped two-Higgs-doublet model","authors":"Dilip Kumar Ghosh, Biswarup Mukhopadhyaya, Sirshendu Samanta, Ritesh K. Singh","doi":"10.1103/nfzx-96x1","DOIUrl":"https://doi.org/10.1103/nfzx-96x1","url":null,"abstract":"The phenomenology of the flipped two-Higgs-doublet model (2HDM) is relatively less explored so far, as compared to the other, commonly discussed, types. It is found that this scenario, like several others, admits of a light neutral pseudoscalar A</a:mi></a:math> in the mass range 20–60 GeV, consistently with all current experimental data and theoretical constraints. However, the fact that such a pseudoscalar decays overwhelmingly into a <c:math xmlns:c=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><c:mi>b</c:mi><c:mover accent=\"true\"><c:mi>b</c:mi><c:mo stretchy=\"false\">¯</c:mo></c:mover></c:math> pair makes its identification at the Large Hadron Collider (LHC) a challenging task. After identifying the region of the flipped 2HDM parameter space yielding a light pseudoscalar, we identify a useful search channel in the process <g:math xmlns:g=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><g:mi>p</g:mi><g:mi>p</g:mi><g:mo stretchy=\"false\">→</g:mo><g:mi>A</g:mi><g:mi>Z</g:mi><g:mo stretchy=\"false\">(</g:mo><g:msup><g:mi>Z</g:mi><g:mo>*</g:mo></g:msup><g:mo stretchy=\"false\">)</g:mo><g:mo stretchy=\"false\">→</g:mo><g:mi>b</g:mi><g:mover accent=\"true\"><g:mi>b</g:mi><g:mo stretchy=\"false\">¯</g:mo></g:mover><g:msup><g:mo>ℓ</g:mo><g:mo>+</g:mo></g:msup><g:msup><g:mo>ℓ</g:mo><g:mo>−</g:mo></g:msup></g:math>. A cut-based analysis, followed by one based on boosted decision trees, shows that the light-<o:math xmlns:o=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><o:mi>A</o:mi></o:math> scenario in flipped 2HDM should be detectable with rather high statistical significance at the high-luminosity LHC run, even after including systematic uncertainties. Furthermore, part of the parameter space, especially around <q:math xmlns:q=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><q:msub><q:mi>m</q:mi><q:mi>A</q:mi></q:msub><q:mo>=</q:mo><q:mn>30</q:mn><q:mi>–</q:mi><q:mn>40</q:mn><q:mtext> </q:mtext><q:mtext> </q:mtext><q:mi>GeV</q:mi></q:math>, is amenable to detection at the discovery level within Run-2 itself.","PeriodicalId":20167,"journal":{"name":"Physical Review D","volume":"101 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2025-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145311438","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":"Toward holography on biregular trees","authors":"Arkapal Mondal, Sarthak Parikh, Pulak Pradhan, Ritu Sengar","doi":"10.1103/ms53-88pp","DOIUrl":"https://doi.org/10.1103/ms53-88pp","url":null,"abstract":"We study scalar field theory on biregular trees, as a new model for discrete holography. Biregular trees are discrete symmetric spaces associated with the bulk isometry group SU</a:mi></a:mrow>(</a:mo>3</a:mn>)</a:mo></a:math> over the unramified quadratic extension of a nonarchimedean field. The bulk-to-bulk and bulk-to-boundary propagators exhibit distinct features absent on the regular tree or continuum AdS spaces, arising from the semihomogeneous nature of the bulk space. We compute the two- and three-point correlators of the putative boundary dual. The three-point correlator exhibits a nontrivial “tensor structure” via dependence on the homogeneity degree of a unique bulk point specified in terms of boundary insertion points. The computed operator product expansion coefficients show dependence on zeta functions associated with the unramified quadratic extension of a nonarchimedean field. This work initiates the formulation of holography on a family of discrete holographic spaces that exhibit features of both flat space and negatively curved space.","PeriodicalId":20167,"journal":{"name":"Physical Review D","volume":"1 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2025-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145311278","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}