Simultaneous measurement of mass and radius with high precision is essential to unravelling the equation of state of matter at the core of neutron stars. Measurement of massive pulsars indicates that they have to be stiff at low densities. In this work, an ensemble of agnostically constructed equations of state was studied for the mass-radius measurement. The radius of neutron stars obtained from the ensemble was confined within a 10.5–14.5 km bound. Among the NICER measurements, PSR J0437–4715 provides the most stringent constraint on the equation of state. It was found that the detection of stars with smaller radii would prefer a softer equation of state, and the detection of stars with larger radii would prefer a stiffer equation of state. However, irrespective of the detection of stars with a smaller or larger radius, the sound speed peak indicates that stars are likely to have a smooth phase transition at a few times saturation densities, and the matter at the core may not be pure conformal quark matter. A better precision of the radius measurement drastically increases the chances of constraining the equation of state. The equation of state would be more effectively constrained if the measurement of large-radius stars with high precision were to happen. Precise radius measurements of neutron stars with smaller radii provide limited constraints on the equation of state over the density range relevant to neutron stars, largely independent of the stellar mass. Also, measurements for different masses are necessary to constrain the equation of state at all density ranges relevant to neutron stars.

India

Asim Saha

Ritam Mallick

The prospect of confining the equation of state of neutron stars with future mass and radius measurements

Modular flavor symmetries have been proposed as a new way to address the flavor problem. It is known that they can emerge from string compactifications. We discuss this connection in detail, and show how the congruence subgroups of SL(2$\textit{,}$ ℤ), which underlie many modular flavor symmetries, emerge from stringy duality symmetries by orbifolding. This requires an analysis of massive states, which reveals a picture that is more intricate than the well-known situation on the torus. It involves towers of states of different quantum numbers, related by modular transformations. Members of different towers become massless at different points in moduli space. We also show that, at least in the ℤ orbifold, the string selection rules can be understood as discrete remnants of continuous gauge symmetries. Non-Abelian discrete flavor symmetries arise as relics of various, relatively misaligned, continuous Abelian gauge symmetries. The generators of these U(1) symmetries give rise to $$ \mathcal{CP} $$ -violating Clebsch-Gordan coefficients. If the modulus settles close to a critical point, the corresponding gauge bosons may be light enough to be searched for at future colliders.

United States

Xueqi Li

Xiang-Gan Liu

Germany

Hans Nilles

Michael Ratz

Alexander Stewart

Flavor symmetries and winding modes

In high-energy collisions far above the electroweak scale, the effects of electroweak symmetry breaking are expected to become parametrically small <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>δ</mi><mo>∼</mo><msub><mrow><mi>M</mi></mrow><mrow><mi>W</mi></mrow></msub><mo>/</mo><mi>E</mi></mrow></math>. This defines the extent to which the electroweak gauge symmetry is restored: (i) the physics of the transverse gauge bosons and fermions is described by a massless theory in the unbroken phase; (ii) the longitudinal gauge bosons behave like the Goldstone bosons and join the Higgs boson to restore the unbroken O(4) symmetry in the original Higgs sector. Using the unique feature of the radiation amplitude zeros in gauge theory, we propose to study the electroweak symmetry restoration quantitatively by examining the processes for the gauge boson pair production <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>W</mi></mrow><mrow><mo>±</mo></mrow></msup><mi>γ</mi><mo>,</mo><msup><mrow><mi>W</mi></mrow><mrow><mo>±</mo></mrow></msup><mi>Z</mi></mrow></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>W</mi></mrow><mrow><mo>±</mo></mrow></msup><mi>H</mi></mrow></math> at the LHC and muon colliders.

Rodolfo Capdevilla

Tao Han

Electroweak Symmetry Restoration and Radiation Amplitude Zeros

We study quantum M2-branes in holographic backgrounds and show that their moduli spaces of zero modes are localized according to an R-symmetry Killing vector. We discuss the relation with recent results in the context of equivariant localization in gauged supergravity and argue its origin within M-theory path integrals expanded in saddle points over M2-branes. We argue that the M2-brane partition function, including its nonperturbative corrections, should be compared to the field theory grand canonical partition function. Our results extend recent observations in the context of the giant graviton expansion of superconformal indices to generic supersymmetric anti–de Sitter boundary conditions. As a byproduct we predict nonperturbative corrections to a variety of supersymmetric observables of the Aharony-Bergman-Jafferis-Maldacena theory.

United Kingdom

Friðrik Freyr Gautason

Jesse van Muiden

Localization of the M2-Brane

We show that primordial adiabatic curvature fluctuations generate an instability of the scalar field sourcing a kination era. We demonstrate that the generated higher Fourier modes constitute a radiationlike component dominating over the kination background after about 11 e-folds of cosmic expansion. Current constraints on the extra number of neutrino flavors <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Δ</mi><msub><mi>N</mi><mi>eff</mi></msub></math> thus imply the observational bound of approximately 10 e-folds, representing the most stringent bound to date on the stiffness of the equation of state of the pre–Big Bang–nucleosynthesis universe.

Türkiye

Cem Eröncel

Israel

Yann Gouttenoire

Japan

Ryosuke Sato

Géraldine Servant

Spain

Peera Simakachorn

Universal Bound on the Duration of a Kination Era

We present the ground-state energy spectra of dibaryons composed of single-flavor quarks, specifically systems with strangeness <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">S</mi><mo>=</mo><mo>−</mo><mn>6</mn></math> and charm <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">C</mi><mo>=</mo><mn>6</mn></math>. Our lattice QCD study is based on <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>N</mi><mi>f</mi></msub><mo>=</mo><mn>2</mn><mo>+</mo><mn>1</mn><mo>+</mo><mn>1</mn></math> MILC ensembles with highly improved staggered quark sea quarks, spanning four lattice spacings and two spatial volumes. We employ valence quark propagators realized using a relativistic overlap action, evaluate correlation matrices with carefully designed operator bases, and extract reliable ground-state energy estimates in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mo>=</mo><mn>0</mn></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mo>=</mo><mn>2</mn></math> spin channels. We explore their binding characteristics and interaction dynamics by examining the energy separation between the dibaryon states and the corresponding two-baryon thresholds. These results contribute to a deeper understanding of single-flavor dibaryon states as a function of the quark masses. In the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mo>=</mo><mn>0</mn></math> channel, the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi mathvariant="normal">Ω</mi></mrow><mrow><mi>c</mi><mi>c</mi><mi>c</mi></mrow></msub><mtext>−</mtext><msub><mrow><mi mathvariant="normal">Ω</mi></mrow><mrow><mi>c</mi><mi>c</mi><mi>c</mi></mrow></msub></mrow></math> system exhibits a clear signal of a bound state, while the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="normal">Ω</mi><mtext>−</mtext><mi mathvariant="normal">Ω</mi></mrow></math> system lies very close to the threshold, making it difficult to draw definitive conclusions. For <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mo>=</mo><mn>2</mn></math>, both systems are found to be unbound.

Navdeep Singh Dhindsa

Nilmani Mathur

M. Padmanath

Lattice QCD study of positive parity dibaryons with maximal charm and strangeness

The neutrino energy reconstruction is crucial for reducing systematic uncertainties in neutrino oscillation experiments and improving cross section measurements. Kaon-decays-at-rest (KDAR) neutrinos provide a unique opportunity to probe neutrino-nucleus interactions at low energies with a precisely known energy of 235.5 MeV. This work presents Monte Carlo predictions of missing energy due to nuclear effects in the KDAR <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ν</mi><mi>μ</mi></msub></math> charged-current scattering on the carbon nucleus for the J-PARC sterile neutrino search at the J-PARC Spallation Neutron Source. The predictions from genie, nuwro, and gibuu show a significant impact of nuclear and final-state interaction (FSI) models, as well as nucleon removal energy, on missing energy reconstruction. Tuning the hA FSI model improves the predictions from genie. It is also observed that the nucleon elastic component of FSI leads to better predictions in nuwro compared to genie. nuwro shows the best agreement with data among the generators considered; however, the observed discrepancies with data across all generators highlight the limitations of current theoretical descriptions in the low-energy regime and the need for improvements in Monte Carlo modeling.

R.K. Pradhan

R. Lalnuntluanga

A. Giri

Monte Carlo study of KDAR <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ν</mi><mi>μ</mi></msub></math> charged-current scattering on carbon

Blazar-boosted dark matter is a novel mechanism whereby dark matter (DM) particles are accelerated to ultrarelativistic energies through interactions with blazar jets. Focusing on a vector portal DM model, we systematically investigate both elastic and inelastic scattering processes between DM and protons. By analyzing multimessenger data from ground- and space-based observatories, we derive stringent constraints on the DM-proton scattering cross section <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>σ</mi><mrow><mi>χ</mi><mi>p</mi></mrow></msub></math>. Our results improve upon previous limits from the constant cross section and pure elastic scattering scenarios by several orders of magnitude. The distinctive high-energy gamma-ray and neutrino fluxes produced through deep inelastic scattering provide powerful signatures for blazar-boosted dark matter indirect detection, enabling constraints that significantly surpass those from traditional direct detection experiments. Notably, our results suggest that DM could be a new source of high-energy neutrinos from blazars, potentially offering an explanation for IceCube’s observation of TXS <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>0506</mn><mo>+</mo><mn>056</mn></mrow></math>.

China

Jin-Wei Wang

Blazar-boosted dark matter: Novel signatures via elastic and inelastic scattering

A new measurement of the magnetic anomaly <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>a</mi></mrow><mrow><mi>μ</mi></mrow></msub></mrow></math> of the positive muon is presented based on data taken from 2020 to 2023 by the Muon <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>g</mi><mo>−</mo><mn>2</mn></math> Experiment at Fermi National Accelerator Laboratory (FNAL). This dataset contains over 2.5 times the total statistics of our previous results. From the ratio of the precession frequencies for muons and protons in our storage ring magnetic field, together with precisely known ratios of fundamental constants, we determine <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>a</mi></mrow><mrow><mi>μ</mi></mrow></msub><mo>=</mo><mrow><mn>1</mn><mtext> </mtext><mn>165</mn><mtext> </mtext><mn>920</mn><mtext> </mtext><mn>710</mn><mo stretchy="false">(</mo><mn>162</mn><mo stretchy="false">)</mo><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>12</mn></mrow></msup></mrow></mrow></math> (139 ppb) for the new datasets, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>a</mi></mrow><mrow><mi>μ</mi></mrow></msub><mo>=</mo><mrow><mn>1</mn><mtext> </mtext><mn>165</mn><mtext> </mtext><mn>920</mn><mtext> </mtext><mn>705</mn><mo stretchy="false">(</mo><mn>148</mn><mo stretchy="false">)</mo><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>12</mn></mrow></msup></mrow></mrow></math> (127 ppb) when combined with our previous results. The new experimental world average, dominated by the measurements at FNAL, is <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>a</mi></mrow><mrow><mi>μ</mi></mrow></msub><mo stretchy="false">(</mo><mi>exp</mi><mo stretchy="false">)</mo><mo>=</mo><mrow><mn>1</mn><mtext> </mtext><mn>165</mn><mtext> </mtext><mn>920</mn><mtext> </mtext><mn>715</mn><mo stretchy="false">(</mo><mn>145</mn><mo stretchy="false">)</mo><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>12</mn></mrow></msup></mrow></mrow></math> (124 ppb). The measurements at FNAL have improved the precision on the world average by over a factor of 4.

D.P. Aguillard

T. Albahri

D. Allspach

J. Annala

K. Badgley

S. Baeßler

I. Bailey

L. Bailey

E. Barlas-Yucel

T. Barrett

E. Barzi

Italy

F. Bedeschi

M. Berz

M. Bhattacharya

H.P. Binney

P. Bloom

J. Bono

E. Bottalico

T. Bowcock

S. Braun

M. Bressler

G. Cantatore

R.M. Carey

B.C.K. Casey

D. Cauz

R. Chakraborty

A. Chapelain

S. Chappa

S. Charity

C. Chen

M. Cheng

R. Chislett

Z. Chu

T.E. Chupp

C. Claessens

F. Confortini

M.E. Convery

S. Corrodi

L. Cotrozzi

J.D. Crnkovic

S. Dabagov

P.T. Debevec

S. Di Falco

G. Di Sciascio

S. Donati

B. Drendel

A. Driutti

M. Eads

A. Edmonds

J. Esquivel

M. Farooq

R. Fatemi

K. Ferraby

C. Ferrari

M. Fertl

A.T. Fienberg

A. Fioretti

D. Flay

S.B. Foster

H. Friedsam

N.S. Froemming

C. Gabbanini

I. Gaines

S. Ganguly

J. George

L.K. Gibbons

A. Gioiosa

K.L. Giovanetti

P. Girotti

W. Gohn

L. Goodenough

T. Gorringe

J. Grange

S. Grant

F. Gray

South Korea

S. Haciomeroglu

T. Halewood-Leagas

D. Hampai

F. Han

J. Hempstead

D.W. Hertzog

G. Hesketh

E. Hess

A. Hibbert

Z. Hodge

S.Y. Hoh

K.W. Hong

R. Hong

T. Hu

Y. Hu

M. Iacovacci

M. Incagli

S. Israel

P. Kammel

M. Kargiantoulakis

M. Karuza

J. Kaspar

D. Kawall

L. Kelton

A. Keshavarzi

Measurement of the Positive Muon Anomalous Magnetic Moment to 127 ppb

<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mtext>DMRadio-</mtext><msup><mrow><mi mathvariant="normal">m</mi></mrow><mrow><mn>3</mn></mrow></msup></mrow></math> is an experimental search for dark matter axions. It uses a solenoidal dc magnetic field to convert an axion dark-matter signal to an ac electromagnetic response in a coaxial copper pickup. The current induced by this axion signal is measured by dc SQUIDs. <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mtext>DMRadio-</mtext><msup><mrow><mi mathvariant="normal">m</mi></mrow><mrow><mn>3</mn></mrow></msup></mrow></math> is designed to be sensitive to Kim-Shifman-Vainshtein-Zakharov (KSVZ) and Dine-Fischler-Srednicki-Zhitnisky (DFSZ) QCD axion models in the 10–200 MHz (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>41</mn><mtext> </mtext><mtext> </mtext><mi>neV</mi><mo>/</mo><msup><mi>c</mi><mn>2</mn></msup><mi>–</mi><mrow><mn>0.83</mn><mtext> </mtext><mtext> </mtext><mi mathvariant="normal">μ</mi><mi>eV</mi><mo>/</mo><msup><mi>c</mi><mn>2</mn></msup></mrow></mrow></math>) range, and to axions with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>g</mi><mrow><mi>a</mi><mi>γ</mi><mi>γ</mi></mrow></msub><mo>=</mo><msub><mi>g</mi><mrow><mi>a</mi><mi>γ</mi><mi>γ</mi><mo>,</mo><mrow><mi>DFSZ</mi></mrow></mrow></msub><mo stretchy="false">(</mo><mn>30</mn><mtext> </mtext><mtext> </mtext><mi>MHz</mi><mo stretchy="false">)</mo><mo>=</mo><mn>1.87</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>17</mn></mrow></msup><mtext> </mtext><mtext> </mtext><msup><mrow><mi>GeV</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></math> over 5–30 MHz as an extended goal. In this work, we present the electromagnetic modeling of the response of the experiment to an axion signal over the full frequency range of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mtext>DMRadio-</mtext><msup><mrow><mi mathvariant="normal">m</mi></mrow><mrow><mn>3</mn></mrow></msup></mrow></math>, which extends from the low-frequency, lumped-element limit to a regime where the axion Compton wavelength is only a factor of 2 larger than the detector size. With these results, we determine the live time and sensitivity of the experiment. The primary science goal of sensitivity to DFSZ axions across 30–200 MHz can be achieved with a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>3</mn><mi>σ</mi></math> live scan time of 2.9 years.

A. AlShirawi

V. Ankel

C. Bartram

J. Begin

C. Bell

J.N. Benabou

L. Brouwer

S. Chaudhuri

H.M. Cho

J. Corbin

W. Craddock

S. Cuadra

A. Droster

J. Echevers

J.W. Foster

J.T. Fry

P.W. Graham

R. Henning

K.D. Irwin

F. Kadribasic

Y. Kahn

A. Keller

R. Kolevatov

S. Kuenstner

A. Kunder

N. Kurita

A.F. Leder

D. Li

N. Otto

J.L. Ouellet

K.M.W. Pappas

A. Phipps

N.M. Rapidis

B.R. Safdi

C.P. Salemi

M. Simanovskaia

J. Singh

P. Stark

E.C. van Assendelft

K. van Bibber

K. Wells

J. Wiedemann

L. Winslow

W.J. Wisniewski

D. Wright

A.K. Yi

B.A. Young

Electromagnetic modeling and science reach of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mtext>DMRadio-</mtext><msup><mrow><mi mathvariant="normal">m</mi></mrow><mrow><mn>3</mn></mrow></msup></mrow></math>