The long-distance contribution of QED corrections to the hadronic vacuum polarization is particularly challenging to compute in lattice <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>QCD</mi><mo>+</mo><mi>QED</mi></mrow></math>. Currently, it is one of the limiting factors toward matching the precision of the recent result by the Fermilab E989 experiment for the muon <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>g</mi><mo>−</mo><mn>2</mn></mrow></math>. In this work, we present a method for obtaining high-precision results for this contribution by reconstructing exclusive finite-volume state contributions. We find relations between the pion-photon contributions of individual diagrams and demonstrate the reconstruction method with lattice <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>QCD</mi><mo>+</mo><mi>QED</mi></mrow></math> data at a single lattice spacing of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>a</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup><mo>≈</mo><mn>1.73</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>π</mi></msub><mo>≈</mo><mn>275</mn><mtext> </mtext><mtext> </mtext><mi>MeV</mi></math>.

Germany

C. Lehner

J. Parrino

A. Völklein

Long-distance reconstruction of QED corrections to the hadronic vacuum polarization for the muon <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>g</mi><mo>−</mo><mn>2</mn></math>

In this study, we investigate a scenario based on the effects of the Loop Quantum Gravity (LQG) on the electromagnetic sector of the Standard Model of Fundamental Interactions and Particle Physics (SM). Starting from a post-Maxwellian version of electromagnetism that includes LQG effects, we derive and discuss the influence of LQG parameters on classical quantities such as the components of the stress-tensor. Furthermore, we inspect the propagation of electromagnetic waves and examine the optical properties of the QED vacuum in this scenario. Among these, we contemplate the combined effect of the LQG parameters and a homogeneous background magnetic field on the propagation of electromagnetic waves by considering issues such as group velocities and refractive indices of the QED vacuum, in detail. Finally, with the aid of the previously analyzed LQG-extended photonic dispersion relations, we re-discuss the kinematics of the Compton effect and conclude that an interesting nonlinear profile emerges in the wavelengths of the incoming and deflected photons.

Brazil

P.A.L. Mourão

G.L.L.W. Levy

J.A. Helayël-Neto

Reassessing aspects of LQG-modified dispersion relations of photons * P. A. L. Mourão is support by CAPES. G. L. L. W. L. Levy is support by the Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ), Grant No. E-26/202.437/2024.

We compute the potential-graviton contributions to the conservative scattering angle of two nonspinning bodies in maximal supergravity at fifth order in Newton’s constant, including second-order self-force effects. Our goal is to tackle the challenging integrals arising at this order in Einstein gravity, but within the technically simpler framework of supergravity. The calculation employs the scattering-amplitude framework, effective field theory, and multiloop integration techniques based on integration by parts and differential equations. The final result is expressed as a series expansion around the static limit, thereby avoiding the explicit evaluation of intricate special functions. This series solution for the master integrals applies, as well, to the corresponding computation in general relativity. Remarkably, we observe nontrivial cancellations among contributions associated with Calabi-Yau integrals, alongside a distinct contribution governed by a Heun differential equation.

United States

Zvi Bern

Enrico Herrmann

Switzerland

Radu Roiban

Michael S. Ruf

Russia

Alexander V. Smirnov

Vladimir A. Smirnov

United Kingdom

Mao Zeng

Second-Order Self-Force Potential-Region Binary Dynamics at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="script">O</mi><mo stretchy="false">(</mo><msup><mrow><mi>G</mi></mrow><mrow><mn>5</mn></mrow></msup><mo stretchy="false">)</mo></mrow></math> in Supergravity

A fermion can be chiral or vectorlike with respect to a given symmetry, depending on its coupling to the corresponding gauge boson. Vectorlike fermions have a distinct property that their left- and right-handed components behave in the same way under the gauge symmetry. In this paper, we investigate an extension of the standard model with an <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mi>U</mi><mo stretchy="false">(</mo><mn>2</mn><mo stretchy="false">)</mo></math> doublet of vectorlike leptons and two complex scalars. The new physics effects on the lepton anomalous magnetic moment, as well as the electron and muon pair production processes at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup></math> colliders are analyzed. Taking into account the updated measurement results of the electron and muon <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>g</mi><mo>−</mo><mn>2</mn></math>, as well as the Large Electron-Positron Collider and the LHC data, the viable parameter space of the model is identified. We also examine the prospect of testing the model using <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>μ</mi><mo>+</mo></msup><msup><mi>μ</mi><mo>−</mo></msup></math> signals from electron-position annihilation at the Future Circular Collider (FCC-ee). The analysis shows that the FCC-ee will be able to exclude a significant part of the parameter space, pinpointing exiguous viable regions to be tested in the future due to its high precision.

Vietnam

Sang Quang Dinh

Hieu Minh Tran

Vectorlike lepton imprints at lepton <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>g</mi><mo>−</mo><mn>2</mn></math> measurements and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>e</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow></math> colliders

We examine electron and muon anomalous magnetic dipole moments within a radiative neutrino mass model featuring TeV-scale scalar leptoquarks <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mo stretchy="false">(</mo><mn>3</mn><mo>,</mo><mn>1</mn><mo>,</mo><mo>−</mo><mn>1</mn><mo>/</mo><mn>3</mn><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>R</mi><mo stretchy="false">(</mo><mn>3</mn><mo>,</mo><mn>2</mn><mo>,</mo><mn>1</mn><mo>/</mo><mn>6</mn><mo stretchy="false">)</mo></math>. We utilize textures with decoupling electron and muon sectors, so that both electron and muon anomalous magnetic dipole moments could receive internal chiral enhancements from different heavy up-type quarks while in the same time evading the stringent <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>μ</mi><mo stretchy="false">→</mo><mi>e</mi><mi>γ</mi></math> constraint. A successful fit to neutrino oscillation data requires the simultaneous presence of one- and two-loop neutrino mass contributions. This severely constrains the parameter space of the model, which results in a negligible new physics correction to the muon <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>g</mi><mo>−</mo><mn>2</mn></math>. The electron <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>g</mi><mo>−</mo><mn>2</mn></math> discrepancy implied by the rubidium experiment, on the other hand, can be resolved within <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2</mn><mi>σ</mi></math> uncertainty provided that neutrino mass ordering is inverted. Lepton-flavor-violating tau decay rates, such as <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>τ</mi><mo stretchy="false">→</mo><mi>e</mi><mi>γ</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>τ</mi><mo stretchy="false">→</mo><mn>3</mn><mi>e</mi></math>, are predicted to be within the sensitivities of next-generation experiments.

Thailand

Indonesia

Bayu Dirgantara

J. Julio

Constraining the new contributions to electron <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>g</mi><mo>−</mo><mn>2</mn></math> in a radiative neutrino mass model

The existence of right-handed neutrinos with Majorana masses below the electroweak scale could help address the origins of neutrino masses, the matter–antimatter asymmetry, and dark matter. In this paper, leptonic decays of $\textit{W}$ bosons from 140 fb $$^{-1}$$ of 13 TeV proton–proton collisions at the LHC, reconstructed in the ATLAS experiment, are used to search for heavy neutral leptons produced through their mixing with muon or electron neutrinos in a scenario with lepton number violation. The search is conducted using prompt leptonic decay signatures. The considered final states require two same-charge leptons or three leptons, while vetoing three-lepton same-flavour topologies. No significant excess over the expected Standard Model backgrounds is found, leading to constraints on the heavy neutral lepton’s mixing with muon and electron neutrinos for heavy-neutral-lepton masses. The analysis excludes $$|U_{e}|^2$$ values above $$8\times 10^{-5}$$ and $$|U_{\mu }|^2$$ values above $$5.0 \times 10^{-5}$$ in the full mass range of 8–65 GeV. The strongest constraints are placed on heavy-neutral-lepton masses in the range 15–30 GeV of $$|U_{e}|^2 < 1.1 \times 10^{-5}$$ and $$|U_{\mu }|^2 < 5 \times 10^{-6}$$ .

France

G. Aad

Norway

E. Aakvaag

B. Abbott

United Arab Emirates

S. Abdelhameed

K. Abeling

N. Abicht

S. Abidi

M. Aboelela

Morocco

A. Aboulhorma

Israel

H. Abramowicz

Y. Abulaiti

Italy

B. Acharya

A. Ackermann

C. Adam Bourdarios

Poland

L. Adamczyk

S. Addepalli

M. Addison

J. Adelman

Türkiye

A. Adiguzel

T. Adye

A. Affolder

Y. Afik

Spain

M. Agaras

A. Aggarwal

Romania

C. Agheorghiesei

Azerbaijan

F. Ahmadov

S. Ahuja

China

X. Ai

G. Aielli

A. Aikot

M. Ait Tamlihat

B. Aitbenchikh

M. Akbiyik

Sweden

T. Åkesson

A. Akimov

Japan

D. Akiyama

N. Akolkar

S. Aktas

G. Alberghi

Canada

J. Albert

U. Alberti

P. Albicocco

G. Albouy

S. Alderweireldt

Z. Alegria

M. Aleksa

I. Aleksandrov

C. Alexa

Greece

T. Alexopoulos

F. Alfonsi

M. Algren

M. Alhroob

Czechia

B. Ali

Saudi Arabia

H. Ali

S. Ali

S. Alibocus

South Africa

M. Aliev

G. Alimonti

W. Alkakhi

C. Allaire

B. Allbrooke

J. Allen

P. Allport

A. Aloisio

Argentina

F. Alonso

C. Alpigiani

Z. Alsolami

A. Alvarez Fernandez

M. Alves Cardoso

M. Alviggi

M. Aly

Y. Coutinho

A. Ambler

C. Amelung

M. Amerl

C. Ames

T. Amezza

D. Amidei

B. Amini

K. Amirie

A. Amirkhanov

Portugal

S. Amor Dos Santos

K. Amos

D. Amperiadou

S. An

C. Anastopoulos

T. Andeen

J. Anders

A. Anderson

A. Andreazza

S. Angelidakis

A. Angerami

A. Anisenkov

A. Annovi

C. Antel

E. Antipov

M. Antonelli

F. Anulli

M. Aoki

Search for heavy neutral leptons in decays of $\textit{W}$ bosons produced in 13 TeV $\textit{pp}$ collisions using prompt signatures in the ATLAS detector

At the Large Hadron Collider, the $\textit{WbWb}$ final state is expected to be dominated by $$ t\overline{t} $$ production with a contribution from single-top processes. Differential cross-sections for $\textit{WbWb}$ production in the dilepton decay channel are measured at the particle level as a function of various kinematic variables. The analysis is based on data from proton-proton collisions at a centre-of-mass energy of $$ \sqrt{s}=13 $$ TeV, recorded by the ATLAS detector at the Large Hadron Collider over the period from 2015 to 2018, corresponding to an integrated luminosity of 140 fb . Measurements are performed within the fiducial phase-space defined by the presence of two $\textit{b}$-jets and one electron and one muon of opposite charges. The differential cross-sections are corrected for detector effects and unfolded to the particle level. Results are compared with predictions from Monte Carlo event generators at next-to-leading order in perturbative quantum chromodynamics; overall the measurements are in reasonable agreement with several generator setups, although no single prediction is able to describe all measured distributions simultaneously. These measurements provide valuable constraints on the modelling of $\textit{WbWb}$ production and the interference between doubly resonant and singly resonant $\textit{WbWb}$ production.

Y. Amaral Coutinho

T. Aoki

Measurements of differential cross-sections of $\textit{WbWb}$ production in the dilepton channel in $\textit{pp}$ collisions at $$ \sqrt{s}=13 $$ TeV using the ATLAS detector

The electromagnetic structure of axial-vector mesons is investigated via elastic and two-photon transition form factors (TFFs). To this end, we employ a framework based on the Dyson-Schwinger and Bethe-Salpeter equations within a contact interaction (CI) model. This largely algebraic approach exposes the role of symmetries and their breaking in a transparent manner, and has proven successful in describing anomaly-sensitive processes, including pseudoscalar to two-photon TFFs, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><mo stretchy="false">→</mo><mn>3</mn><mi>π</mi></math>, and vector-to-pseudoscalar radiative decays. Restricting our analysis to the lowest-lying axial-vector meson multiplet, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="normal">A</mi><mo>=</mo><mo stretchy="false">{</mo><msub><mrow><mi>a</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>,</mo><msub><mrow><mi>f</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>,</mo><msubsup><mrow><mi>f</mi></mrow><mrow><mn>1</mn></mrow><mrow><mo>′</mo></mrow></msubsup><mo stretchy="false">}</mo></mrow></math>, we also explore the corresponding light-by-light contribution to the muon anomalous magnetic moment. This contribution is underestimated in the CI model mainly due to the normalization of the TFFs. After applying a phenomenologically motivated rescaling to the TFFs, a process required given the limitations of the CI model, we obtain <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msubsup><mrow><mi>a</mi></mrow><mrow><mi>μ</mi></mrow><mrow><mi mathvariant="normal">A</mi></mrow></msubsup><mo>=</mo><mn>8.1</mn><msubsup><mrow><mn>6</mn></mrow><mrow><mo>−</mo><mn>1.02</mn></mrow><mrow><mo>+</mo><mn>1.22</mn></mrow></msubsup><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>11</mn></mrow></msup></mrow></math>, consistent with contemporary assessments.

Zanbin Xing

Lei Chang

Khépani Raya

Electromagnetic structure of axial-vector mesons and implications for the muon <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>g</mi><mo>−</mo><mn>2</mn></math>

In this study, we investigate the attributes of compact stars within the configuration of <math altimg='si12.svg'><mrow><mi>f</mi><mo>(</mo><mi mathvariant='script'>G</mi><mo>,</mo><mi>&#966;</mi><mo>)</mo></mrow></math> gravity, by incorporating the Gauss-Bonnet term <italic>G</italic> and a scalar field &#966;. By adopting different functional forms of <math altimg='si12.svg'><mrow><mi>f</mi><mo>(</mo><mi mathvariant='script'>G</mi><mo>,</mo><mi>&#966;</mi><mo>)</mo></mrow></math>, we analyze their impact on the equilibrium structure of dense stellar objects. Further, we adopt the Krori-Barua metric potential, defined as <math altimg='si13.svg'><mrow><mi>&#957;</mi><mrow><mo>(</mo><mi>r</mi><mo>)</mo></mrow><mo linebreak='goodbreak'>=</mo><mi>B</mi><msup><mi>r</mi><mn>2</mn></msup><mo linebreak='goodbreak'>+</mo><mi>C</mi></mrow></math> and <math altimg='si14.svg'><mrow><mi>&#955;</mi><mrow><mo>(</mo><mi>r</mi><mo>)</mo></mrow><mo linebreak='goodbreak'>=</mo><mi>A</mi><msup><mi>r</mi><mn>2</mn></msup><mo>,</mo></mrow></math> here, <italic>A, B</italic> and <italic>C</italic> are constants. To ensure a physically viable compact configuration, we impose matching conditions between the interior spherically symmetric space-time and the Schwarzschild geometry. Moreover, we investigate the attributes of the celestial star models by assuming the <math altimg='si12.svg'><mrow><mi>f</mi><mo>(</mo><mi mathvariant='script'>G</mi><mo>,</mo><mi>&#966;</mi><mo>)</mo></mrow></math> gravity model. We attain the modified field equations and examine key physical characteristics, namely energy density and pressure components, stability conditions, equation of state, and energy constraints. These findings provide new insights into the viability of alternative gravity models in explaining extreme astrophysical environments and offer potential observational signatures to constrain <math altimg='si12.svg'><mrow><mi>f</mi><mo>(</mo><mi mathvariant='script'>G</mi><mo>,</mo><mi>&#966;</mi><mo>)</mo></mrow></math> gravity through future gravitational wave and electromagnetic observations.

Pakistan

Zoya Asghar

Jordan

M. Farasat Shamir

Fatemah Mofarreh

Uzbekistan

Javlon Rayimbaev

Otaboyev Sirajiddin

Fayzullo Shayimov

Exploring compact stars in modified <math altimg='si12.svg'><mrow><mi>f</mi><mo>(</mo><mi mathvariant='script'>G</mi><mo>,</mo><mi>&#966;</mi><mo>)</mo></mrow></math> gravity

We compute the classical one-loop gravitational Compton amplitude describing the scattering of a graviton off a massive spinning compact object at the second post-Minkowskian order, including terms through the quartic order in spin. Our analysis includes spin-induced finite-size effects up to the hexadecapolar order and extends recent results obtained for minimal couplings at the quadratic order in spin. From the amplitude, we determine the scattering phase in momentum space, applicable in both the eikonal and wave regimes. In the eikonal limit, we then isolate the spin-independent contribution of the graviton field, explicitly linking it to the dynamics of a massless scalar probe in a Kerr background. This constitutes the first complete description of classical one-loop Compton scattering for generic spinning compact objects at the second post-Minkowskian and hexadecapolar orders.

Dogan Akpinar

Scattering gravitons off general spinning compact objects to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="normal">O</mi><mo stretchy="false">(</mo><msup><mrow><mi>G</mi></mrow><mrow><mn>2</mn></mrow></msup><msup><mrow><mi>S</mi></mrow><mrow><mn>4</mn></mrow></msup><mo stretchy="false">)</mo></mrow></math>