{"title":"Symmetric Mass Generation with Four SU(2) Doublet Fermions","authors":"Nouman Butt, Simon Catterall, Anna Hasenfratz","doi":"10.1103/physrevlett.134.031602","DOIUrl":"https://doi.org/10.1103/physrevlett.134.031602","url":null,"abstract":"We study a single exactly massless staggered fermion in the fundamental representation of an SU(2) gauge group. We utilize an nHYP-smeared fermion action supplemented with additional heavy Pauli-Villars fields that serve to decrease lattice artifacts. The phase diagram exhibits a clear two-phase structure with a conformal phase at weak coupling and a novel new phase, the symmetric mass generation (SMG) phase, appearing at strong coupling. The SMG phase is confining with all states gapped and chiral symmetry unbroken. Our finite size scaling analysis provides strong evidence that the phase transition between these two phases is continuous, which would allow for the existence of a continuum SMG phase. Furthermore, the renormalization group flows are consistent with a β</a:mi></a:math> function that vanishes quadratically at the new fixed point, suggesting that the <c:math xmlns:c=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><c:msub><c:mi>N</c:mi><c:mi>f</c:mi></c:msub><c:mo>=</c:mo><c:mn>4</c:mn></c:math> flavor SU(2) gauge theory lies at the opening of the conformal window. <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":20069,"journal":{"name":"Physical review letters","volume":"35 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143031226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Atomic Description of the Reciprocal Action between Supercoils and Melting Bubbles on Linear DNA","authors":"Matthew Burman, Agnes Noy","doi":"10.1103/physrevlett.134.038403","DOIUrl":"https://doi.org/10.1103/physrevlett.134.038403","url":null,"abstract":"Although the mechanical response of DNA to physiological torsion and tension is well characterized, the detailed structures are not yet known. By using molecular dynamics simulations on linear DNA with 300 base-pairs, we provide, for the first time, the conformational phase diagram at atomic resolution. Our simulations also reveal the dynamics and diffusion of supercoils. We observe a new state in negative supercoiling, where denaturation bubbles form in adenine/thymine-rich regions independently of the underlying DNA topology. We thus propose sequence-dependent bubbles could position plectonemes in longer DNA. <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":20069,"journal":{"name":"Physical review letters","volume":"15 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143031183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Hidden Zeros Are Equivalent to Enhanced Ultraviolet Scaling, and Lead to Unique Amplitudes in Tr(ϕ3) Theory","authors":"Laurentiu Rodina","doi":"10.1103/physrevlett.134.031601","DOIUrl":"https://doi.org/10.1103/physrevlett.134.031601","url":null,"abstract":"We investigate the hidden amplitude zeros which describe a nontrivial vanishing of scattering amplitudes on special external kinematics. We first prove that every type of hidden zero is equivalent to what we call a “subset” enhanced scaling under Britto-Cachazo-Feng-Witten shifts for any rational function built from planar Lorentz invariants X</a:mi></a:mrow>i</a:mi>j</a:mi></a:mrow></a:msub>=</a:mo>(</a:mo>p</a:mi></a:mrow>i</a:mi></a:mrow></a:msub>+</a:mo>p</a:mi></a:mrow>i</a:mi>+</a:mo>1</a:mn></a:mrow></a:msub>+</a:mo>⋯</a:mo>+</a:mo>p</a:mi></a:mrow>j</a:mi>−</a:mo>1</a:mn></a:mrow></a:msub>)</a:mo></a:mrow>2</a:mn></a:mrow></a:msup></a:mrow></a:math>. This directly applies to <e:math xmlns:e=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><e:mi>Tr</e:mi><e:mo stretchy=\"false\">(</e:mo><e:msup><e:mi>ϕ</e:mi><e:mn>3</e:mn></e:msup><e:mo stretchy=\"false\">)</e:mo></e:math>, nonlinear sigma models, or Yang-Mills-scalar amplitudes, revealing a novel type of enhanced UV scaling in these theories. We also use this observation to prove the conjecture that <i:math xmlns:i=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><i:mi>Tr</i:mi><i:mo stretchy=\"false\">(</i:mo><i:msup><i:mi>ϕ</i:mi><i:mn>3</i:mn></i:msup><i:mo stretchy=\"false\">)</i:mo></i:math> amplitudes are uniquely fixed by the zeros, up to an overall normalization, when assuming an ordered and local propagator structure and trivial numerators. In this context, unitarity (residue factorization) may be viewed as a consequence of the zeros. For Yang-Mills theory, we conjecture the zeros, combined with the Bern-Carrasco-Johansson color-kinematic duality in the form of amplitude relations, uniquely fix the <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><m:mo stretchy=\"false\">⌊</m:mo><m:mi>n</m:mi><m:mo>/</m:mo><m:mn>2</m:mn><m:mo stretchy=\"false\">⌋</m:mo></m:math> distinct polarization structures of <q:math xmlns:q=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><q:mi>n</q:mi></q:math>-point gluon amplitudes. Our approach opens a new avenue for understanding previous similar uniqueness results, and also extending them beyond tree level for the first time. <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":20069,"journal":{"name":"Physical review letters","volume":"22 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143031185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Melina Filzinger, Ashlee R. Caddell, Dhruv Jani, Martin Steinel, Leonardo Giani, Nils Huntemann, Benjamin M. Roberts
{"title":"Ultralight Dark Matter Search with Space-Time Separated Atomic Clocks and Cavities","authors":"Melina Filzinger, Ashlee R. Caddell, Dhruv Jani, Martin Steinel, Leonardo Giani, Nils Huntemann, Benjamin M. Roberts","doi":"10.1103/physrevlett.134.031001","DOIUrl":"https://doi.org/10.1103/physrevlett.134.031001","url":null,"abstract":"We devise and demonstrate a method to search for nongravitational couplings of ultralight dark matter to standard model particles using space-time separated atomic clocks and cavity-stabilized lasers. By making use of space-time separated sensors, which probe different values of an oscillating dark matter field, we can search for couplings that cancel in typical local experiments. This provides sensitivity to both the temporal and spatial fluctuations of the field. We demonstrate this method using existing data from a frequency comparison of lasers stabilized to two optical cavities connected via a 2220 km fiber link [Schioppo , ], and from the atomic clocks on board the global positioning system satellites. Our analysis results in constraints on the coupling of scalar dark matter to electrons, d</a:mi>m</a:mi>e</a:mi></a:msub></a:msub></a:math>, for masses between <c:math xmlns:c=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><c:mrow><c:msup><c:mrow><c:mn>10</c:mn></c:mrow><c:mrow><c:mo>−</c:mo><c:mn>19</c:mn></c:mrow></c:msup></c:mrow></c:math> and <e:math xmlns:e=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><e:mrow><e:mn>2</e:mn><e:mo>×</e:mo><e:msup><e:mrow><e:mn>10</e:mn></e:mrow><e:mrow><e:mo>−</e:mo><e:mn>15</e:mn></e:mrow></e:msup><e:mtext> </e:mtext><e:mtext> </e:mtext><e:mi>eV</e:mi><e:mo>/</e:mo><e:msup><e:mrow><e:mi>c</e:mi></e:mrow><e:mrow><e:mn>2</e:mn></e:mrow></e:msup></e:mrow></e:math>. These are the first constraints on <g:math xmlns:g=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><g:msub><g:mi>d</g:mi><g:msub><g:mi>m</g:mi><g:mi>e</g:mi></g:msub></g:msub></g:math> alone in this mass range. <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":20069,"journal":{"name":"Physical review letters","volume":"138 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143026299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Nico J. Guth, Oskar Vallhagen, Per Helander, Istvan Pusztai, Sarah L. Newton, Tünde Fülöp
{"title":"Pellet Rocket Effect in Magnetic Confinement Fusion Plasmas","authors":"Nico J. Guth, Oskar Vallhagen, Per Helander, Istvan Pusztai, Sarah L. Newton, Tünde Fülöp","doi":"10.1103/physrevlett.134.035101","DOIUrl":"https://doi.org/10.1103/physrevlett.134.035101","url":null,"abstract":"Pellets of frozen material traveling into a magnetically confined fusion plasma are accelerated by the so-called pellet rocket effect. The nonuniform plasma heats the pellet ablation cloud asymmetrically, producing pressure-driven, rocketlike propulsion of the pellet. We present a semianalytical model of this process by perturbing a spherically symmetric ablation model. Predicted pellet accelerations match experimental estimates in current tokamaks (∼</a:mo>10</a:mn></a:mrow>5</a:mn></a:mrow></a:msup></a:mtext></a:mtext>m</a:mi>/</a:mo>s</a:mi></a:mrow>2</a:mn></a:mrow></a:msup></a:mrow></a:math>). Projections for ITER high-confinement scenarios (<e:math xmlns:e=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><e:mrow><e:mo>∼</e:mo><e:msup><e:mrow><e:mn>10</e:mn></e:mrow><e:mrow><e:mn>6</e:mn></e:mrow></e:msup><e:mtext> </e:mtext><e:mtext> </e:mtext><e:mtext> </e:mtext><e:mi mathvariant=\"normal\">m</e:mi><e:mo>/</e:mo><e:msup><e:mrow><e:mi mathvariant=\"normal\">s</e:mi></e:mrow><e:mrow><e:mn>2</e:mn></e:mrow></e:msup></e:mrow></e:math>) indicate significantly shorter pellet penetration than expected without this effect, which could limit the effectiveness of disruption mitigation. <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":20069,"journal":{"name":"Physical review letters","volume":"13 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143027139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Simone Salvatore Li Muli, Thomas R. Richardson, Sonia Bacca
{"title":"Revisiting the Helium Isotope-Shift Puzzle with Improved Uncertainties from Nuclear Structure Corrections","authors":"Simone Salvatore Li Muli, Thomas R. Richardson, Sonia Bacca","doi":"10.1103/physrevlett.134.032502","DOIUrl":"https://doi.org/10.1103/physrevlett.134.032502","url":null,"abstract":"Measurements of the difference between the squared charge radii of the helion (He</a:mi></a:mrow>3</a:mn></a:mrow></a:mmultiscripts></a:mrow></a:math> nucleus) and the <c:math xmlns:c=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><c:mi>α</c:mi></c:math> particle (<e:math xmlns:e=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><e:mrow><e:mmultiscripts><e:mrow><e:mi>He</e:mi></e:mrow><e:mprescripts/><e:none/><e:mrow><e:mn>4</e:mn></e:mrow></e:mmultiscripts></e:mrow></e:math> nucleus) have been characterized by longstanding tensions recently spotlighted in the <g:math xmlns:g=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><g:mrow><g:mn>3.6</g:mn><g:mi>σ</g:mi></g:mrow></g:math> discrepancy of the extractions from ordinary atoms versus those from muonic atoms [Karsten Schuhmann , ]. Here, we present a novel analysis of uncertainties in nuclear structure corrections that must be supplied by theory to enable the extraction of the difference in radii from spectroscopic experiments. We use modern Bayesian inference techniques to quantify uncertainties stemming from the truncation of the chiral effective field theory expansion of the nuclear force for both muonic and ordinary atoms. With the new nuclear structure input, the helium isotope-shift puzzle cannot be explained, rather, it is reinforced to a <i:math xmlns:i=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><i:mrow><i:mn>4</i:mn><i:mi>σ</i:mi></i:mrow></i:math> discrepancy. <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":20069,"journal":{"name":"Physical review letters","volume":"13 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143027140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Richard Mcnair, Fernando Temprano-Coleto, François J. Peaudecerf, Frédéric Gibou, Paolo Luzzatto-Fegiz, Oliver E. Jensen, Julien R. Landel
{"title":"Exogenous–Endogenous Surfactant Interaction Yields Heterogeneous Spreading in Complex Branching Networks","authors":"Richard Mcnair, Fernando Temprano-Coleto, François J. Peaudecerf, Frédéric Gibou, Paolo Luzzatto-Fegiz, Oliver E. Jensen, Julien R. Landel","doi":"10.1103/physrevlett.134.034001","DOIUrl":"https://doi.org/10.1103/physrevlett.134.034001","url":null,"abstract":"Experiments have shown that surfactant introduced to a liquid-filled maze can find the solution path. We reveal how the maze-solving dynamics arise from interactions between the added surfactant and endogenous surfactant present at the liquid surface. We simulate the dynamics using a nonlinear model solved with a discrete mimetic scheme on a graph. Endogenous surfactant transforms local spreading into a nonlocal problem with an omniscient view of the maze geometry, key to the maze-solving dynamics. Our results offer insight into surfactant-driven transport in complex networks such as lung airways. <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":20069,"journal":{"name":"Physical review letters","volume":"13 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143026599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Bakul Agarwal, Stephen Jones, Matthias Kerner, Andreas von Manteuffel
{"title":"Complete Next-to-Leading Order QCD Corrections to ZZ Production in Gluon Fusion","authors":"Bakul Agarwal, Stephen Jones, Matthias Kerner, Andreas von Manteuffel","doi":"10.1103/physrevlett.134.031901","DOIUrl":"https://doi.org/10.1103/physrevlett.134.031901","url":null,"abstract":"We calculate the complete next-to-leading order (NLO) QCD corrections to loop-induced g</a:mi>g</a:mi>→</a:mo>Z</a:mi>Z</a:mi></a:mrow></a:math> production including full top-quark mass effects. The two-loop virtual corrections are obtained by combining analytic results for the massless, Higgs-mediated, and one-loop factorizable contributions with numerically computed amplitudes containing the top-quark mass. We show that the choice of subtraction scheme for the virtual contribution impacts the precision with which the virtual contribution must be evaluated in order to obtain sufficiently precise phenomenological predictions. For direct production through a massive top-quark loop, we observe that the relative NLO corrections are large. The direct massive and Higgs-mediated contributions individually increase relative to the massless production at high diboson invariant mass, but interfere destructively with each other. At the Large Hadron Collider, the NLO corrections to the gluon channel give a sizable contribution to the <d:math xmlns:d=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><d:mrow><d:mi>p</d:mi><d:mi>p</d:mi><d:mo stretchy=\"false\">→</d:mo><d:mi>Z</d:mi><d:mi>Z</d:mi><d:mo>+</d:mo><d:mi>X</d:mi></d:mrow></d:math> cross section at <g:math xmlns:g=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><g:mrow><g:msup><g:mrow><g:mi mathvariant=\"normal\">N</g:mi></g:mrow><g:mrow><g:mn>3</g:mn></g:mrow></g:msup><g:mi>LO</g:mi></g:mrow></g:math>. <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":20069,"journal":{"name":"Physical review letters","volume":"15 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143020668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
José Ángel Castellanos-Reyes, Paul M. Zeiger, Ján Rusz
{"title":"Dynamical Theory of Angle-Resolved Electron Energy Loss and Gain Spectroscopies of Phonons and Magnons in Transmission Electron Microscopy Including Multiple Scattering Effects","authors":"José Ángel Castellanos-Reyes, Paul M. Zeiger, Ján Rusz","doi":"10.1103/physrevlett.134.036402","DOIUrl":"https://doi.org/10.1103/physrevlett.134.036402","url":null,"abstract":"We present a method for computing angle-resolved electron energy loss and gain spectroscopies for phonon and magnon excitations in transmission electron microscopy. Fractional scattering intensities are derived from the temperature-dependent time autocorrelation of the auxiliary electron beam wave function. This method captures both single and multiple scattering processes, as well as dynamical diffraction effects, while remaining computationally efficient and easy to parallelize. <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":20069,"journal":{"name":"Physical review letters","volume":"51 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143020670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Optimal Reconstruction of the Hellings and Downs Correlation","authors":"Bruce Allen, Joseph D. Romano","doi":"10.1103/physrevlett.134.031401","DOIUrl":"https://doi.org/10.1103/physrevlett.134.031401","url":null,"abstract":"Pulsar timing arrays (PTAs) detect gravitational waves (GWs) via the correlations they create in the arrival times of pulses from different pulsars. The mean correlation, a function of the angle between the directions to two pulsars, was predicted in 1983 by Hellings and Downs (HD). Observation of this angular pattern is crucial evidence that GWs are present, so PTAs “reconstruct the HD curve” by estimating the correlation using pulsar pairs separated by similar angles. Several studies have examined the amount by which this curve is expected to differ from the HD mean. The variance arises because (a) a finite set of pulsars at specific sky locations is used, (b) the GW sources interfere, and (c) the data are contaminated by noise. Here, for a Gaussian ensemble of sources, we predict that variance by constructing an optimal estimator of the HD correlation, taking into account the pulsar sky locations and the frequency distribution of the GWs and the pulsar noise. The variance is a ratio: the numerator depends upon the pulsar sky locations, and the denominator is the (effective) number of frequency bins for which the GW signal dominates the noise. In effect, after suitable combination, each such frequency bin gives an independent estimate of the HD correlation. <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":20069,"journal":{"name":"Physical review letters","volume":"48 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143020669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}