We revisit the renormalization of models with two U(1) gauge symmetries, in a formulation with noncanonical gauge kinetic terms which is covariant under field reparametrizations among the two gauge bosons. This approach is convenient to study the appearance of kinetic mixing in scale evolution because a coupling matrix is attributed to the gauge kinetic terms. We obtain simple <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mover accent="true"><mrow><mi>MS</mi></mrow><mo stretchy="true">¯</mo></mover></math> renormalization group equations up to two-loop, which can be solved to give effective millicharges at low energy which depend on the running couplings and heavy mass scales of the model. This formulation allows one to construct “invariants” out of running Lagrangian parameters, which are invariant under generic gauge field reparametrizations, including rescalings, and which can be related directly to observables such as the millicharge.

France

Sacha Davidson

United Kingdom

Martin Gorbahn

Renormalization and invariants for two U(1)s

We study the real-time quantum dynamics of a matrix model consisting two bosonic fields on the fuzzy sphere <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msubsup><mrow><mi>S</mi></mrow><mrow><mi>F</mi></mrow><mrow><mn>2</mn></mrow></msubsup></mrow></math> using the Gaussian state approximation. Starting from the Hamiltonian formulation and using Wick’s theorem, we derive a closed set of coupled nonlinear differential equations governing the time evolution of the one- and two-point correlation functions. The thermal equation of state is found by maximizing the von Neumann entropy over Gaussian states and solving the algebraic self-consistency equation(s) leading to a complete determination of the symplectic spectrum of the covariance matrix. We identify near-thermal initial conditions and use them to solve the equations of motion and employ our findings to probe chaos by calculating the largest Lyapunov exponent at various temperatures. Our results demonstrate that the latter tends to zero at a finite temperature indicating that the quantum dynamics respect the Maldacena-Shenker-Stanford bound across all temperatures, while approaching toward the classically chaotic regime at high temperatures. Finally, we examine the entanglement dynamics of the model in real-time by considering a sequence of bipartitions of the Hilbert space and computing the entanglement entropy and clearly exhibit the fast scrambling features that emerge in due detail.

Türkiye

S. Kürkcüoğlu

B. Özcan

Real-time quantum dynamics on the fuzzy sphere: Chaos and entanglement

The Standard Model (SM) cannot explain the observed baryon asymmetry of the Universe (BAU), thus driving the need for physics beyond the SM, which can generate the electroweak baryogenesis through a strong first-order electroweak phase transition (SFOPT). We extend the SM with a complex singlet scalar (cxSM) and examine the phase transition dynamics using a fully general renormalizable scalar potential that permits a complex vacuum expectation value for the singlet scalar and coupled dynamics among multiple scalar fields. Employing the full one-loop thermal effective potential, we conduct an extensive parameter space scan, enforcing both theoretical and experimental constraints on the scalar sector. To efficiently capture the highly nonlinear structure of model parameter space, we embark on a classifier based machine learning approach to identify regions manifesting SFOPT while revealing key signatures of model parameters. From these regions, we select a few representative benchmark scenarios that show multistage transitions followed by the production of stochastic gravitational wave signals from bubble nucleation dynamics. The resulting spectra fall within the projected sensitivities of future space-based detectors such as LISA, BBO, DECIGO, and U-DECIGO. Thus, the cxSM offers a compelling setting for the electroweak baryogenesis, enriched by correlated gravitational wave and collider phenomenology.

India

Dilip Kumar Ghosh

Debadrita Mukherjee

Koustav Mukherjee

Rohan Pramanick

Complex scalar singlet model: Electroweak phase transition and gravitational waves

Using <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> collision data collected with the BESIII detector at the BEPCII collider corresponding to a total integrated luminosity of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>44</mn><mtext> </mtext><mtext> </mtext><msup><mi>fb</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math>, we present the first measurement of the Born cross sections for the process <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><mo stretchy="false">→</mo><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup><msup><mover accent="true"><mi mathvariant="normal">Ξ</mi><mo stretchy="false">¯</mo></mover><mo>+</mo></msup><msup><mi mathvariant="normal">Σ</mi><mo>−</mo></msup></math> at 56 center-of-mass energies from 3.510 to 4.951 GeV. By fitting the dressed cross sections of <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><mo stretchy="false">→</mo><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup><msup><mover accent="true"><mi mathvariant="normal">Ξ</mi><mo stretchy="false">¯</mo></mover><mo>+</mo></msup><msup><mi mathvariant="normal">Σ</mi><mo>−</mo></msup></math> with the assumption of a power-law function plus a charmonium(-like) resonance, i.e., <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>ψ</mi><mo stretchy="false">(</mo><mn>3770</mn><mo stretchy="false">)</mo></mrow></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ψ</mi><mo stretchy="false">(</mo><mn>4040</mn><mo stretchy="false">)</mo></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ψ</mi><mo stretchy="false">(</mo><mn>4160</mn><mo stretchy="false">)</mo></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Y</mi><mo stretchy="false">(</mo><mn>4230</mn><mo stretchy="false">)</mo></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Y</mi><mo stretchy="false">(</mo><mn>4360</mn><mo stretchy="false">)</mo></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ψ</mi><mo stretchy="false">(</mo><mn>4415</mn><mo stretchy="false">)</mo></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Y</mi><mo stretchy="false">(</mo><mn>4500</mn><mo stretchy="false">)</mo></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Y</mi><mo stretchy="false">(</mo><mn>4660</mn><mo stretchy="false">)</mo></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Y</mi><mo stretchy="false">(</mo><mn>4710</mn><mo stretchy="false">)</mo></math>, no significant signal of any charmonium(-like) state decaying into the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup><msup><mover accent="true"><mi mathvariant="normal">Ξ</mi><mo stretchy="false">¯</mo></mover><mo>+</mo></msup><msup><mi mathvariant="normal">Σ</mi><mo>−</mo></msup></math> is observed. Upper limits on the product of the electronic width and branching fraction at the 90% confidence level are given for each resonance. Combining this result with the previous measurement of the isospin-symmetric process <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><mo stretchy="false">→</mo><msup><mi>K</mi><mo>−</mo></msup><msup><mover accent="true"><mi mathvariant="normal">Ξ</mi><mo stretchy="false">¯</mo></mover><mo>+</mo></msup><msup><mi mathvariant="normal">Σ</mi><mn>0</mn></msup></math>, the ratio of the Born cross sections, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>R</mi><mo>=</mo><msup><mrow><mi>σ</mi></mrow><mrow><mi>B</mi></mrow></msup><mo stretchy="false">(</mo><msup><mrow><mi>e</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup><mo stretchy="false">→</mo><msubsup><mrow><mi>K</mi></mrow><mrow><mi>S</mi></mrow><mrow><mn>0</mn></mrow></msubsup><msup><mrow><mover accent="true"><mrow><mi mathvariant="normal">Ξ</mi></mrow><mrow><mo stretchy="false">¯</mo></mrow></mover></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi mathvariant="normal">Σ</mi></mrow><mrow><mo>−</mo></mrow></msup><mo stretchy="false">)</mo><mo>/</mo><mspace linebreak="goodbreak"></mspace><msup><mrow><mi>σ</mi></mrow><mrow><mi>B</mi></mrow></msup><mo stretchy="false">(</mo><msup><mrow><mi>e</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup><mo stretchy="false">→</mo><msup><mrow><mi>K</mi></mrow><mrow><mo>−</mo></mrow></msup><msup><mrow><mover accent="true"><mrow><mi mathvariant="normal">Ξ</mi></mrow><mrow><mo stretchy="false">¯</mo></mrow></mover></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi mathvariant="normal">Σ</mi></mrow><mrow><mn>0</mn></mrow></msup><mo stretchy="false">)</mo></mrow></math>, is found to be consistent with unity.

China

M. Ablikim

Russia

M.N. Achasov

Sweden

P. Adlarson

X.C. Ai

Italy

C.S. Akondi

Germany

R. Aliberti

A. Amoroso

Q. An

Y.H. An

Y. Bai

JINR

O. Bakina

H.R. Bao

X.L. Bao

M. Barbagiovanni

Poland

V. Batozskaya

Mongolia

K. Begzsuren

N. Berger

M. Berlowski

M.B. Bertani

D. Bettoni

F. Bianchi

E. Bianco

A. Bortone

I. Boyko

United States

R.A. Briere

A. Brueggemann

D. Cabiati

H. Cai

M.H. Cai

X. Cai

A. Calcaterra

G.F. Cao

N. Cao

S.A. Cetin

X.Y. Chai

J.F. Chang

T.T. Chang

G.R. Che

Y.Z. Che

C.H. Chen

Chao Chen

G. Chen

H.S. Chen

H.Y. Chen

M.L. Chen

S.J. Chen

S.M. Chen

T. Chen

W. Chen

X.R. Chen

X.T. Chen

X.Y. Chen

Y.B. Chen

Y.Q. Chen

Z.K. Chen

J. Cheng

L.N. Cheng

South Korea

S.K. Choi

X. Chu

G. Cibinetto

F. Cossio

J. Cottee-Meldrum

H.L. Dai

J.P. Dai

X.C. Dai

A. Dbeyssi

R.E. de Boer

D. Dedovich

C.Q. Deng

Z.Y. Deng

A. Denig

I. Denisenko

M. Destefanis

F. De Mori

E. Di Fiore

X.X. Ding

Y. Ding

Y.X. Ding

Yi. Ding

J. Dong

L.Y. Dong

M.Y. Dong

X. Dong

M.C. Du

S.X. Du

Shaoxu Du

X.L. Du

Y.Q. Du

Y.Y. Duan

Z.H. Duan

P. Egorov

G.F. Fan

J.J. Fan

Y.H. Fan

J. Fang

Jin Fang

S.S. Fang

W.X. Fang

Y.Q. Fang

L. Fava

Measurement of the Born cross section for <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><mo stretchy="false">→</mo><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup><msup><mover accent="true"><mi mathvariant="normal">Ξ</mi><mo stretchy="false">¯</mo></mover><mo>+</mo></msup><msup><mi mathvariant="normal">Σ</mi><mo>−</mo></msup></math> at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msqrt><mrow><mi>s</mi></mrow></msqrt><mo>=</mo><mn>3.51</mn><mi>–</mi><mn>4.95</mn><mrow><mtext> </mtext><mtext> </mtext><mi>GeV</mi></mrow></mrow></math>

We derive compact analytical formulas for the spectrum of nonlinear Compton scattering in a finite plane-wave pulse with a smooth temporal envelope. The strong-field QED probability is reduced to finite-pulse phase integrals, which are evaluated asymptotically for multicycle pulses with a broad class of smooth envelopes. We use the uniform approximation to remove the caustic divergences that appear at the nonlinear edges of broadened harmonics. Away from the caustics, it reduces to the standard saddle-point result. The behavior near the linear edge is further improved by an envelope-corrected saddle-point approximation. The approach retains the harmonic substructure in the spectral-angular region carrying the dominant part of the emitted radiation. The locally monochromatic approximation is recovered by averaging the finite-pulse interference. Within their asymptotic domain of applicability, the resulting formulas agree with direct numerical calculations and can be used to evaluate spectra from an electron beam.

M.P. Malakhov

Czechia

Th. Benahmed

E.G. Gelfer

A.M. Fedotov

O. Klimo

S. Weber

S.G. Rykovanov

Analytical calculation of the spectrum of nonlinear Compton scattering beyond local approximations

We study the use of higher-order resummation for transverse observables to achieve <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>NNLO</mi><mo>+</mo><mi>PS</mi></mrow></math> matching within the geneva framework. In particular, we embed <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>q</mi><mi>T</mi></msub></math> resummation for color-singlet production at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi mathvariant="normal">N</mi><mn>3</mn></msup><mi>LL</mi></math> obtained via soft-collinear effective theory and implemented in the library scetlib within geneva. We also study for the first time the use of the generalized <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi></math>-jettiness variable in parton shower matching, and achieve the resummation of the one-jettiness defined with transverse measures up to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>NLL</mi><mo>′</mo></msup></math> accuracy. As a case study, we use these resummed calculations to construct a geneva <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>NNLO</mi><mo>+</mo><mi>PS</mi></mrow></math> generator for Higgs boson production in heavy-quark annihilation (with beauty or charm quarks in the initial state). The use of transverse measures facilitates the matching to showers ordered in transverse momentum, and opens the door to possible future extensions of this approach to the production of color singlets in association with final-state jets.

Alessandro Gavardi

Rebecca von Kuk

Matthew A. Lim

Resumming transverse observables for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>NNLO</mi><mo>+</mo><mi>PS</mi></mrow></math> matching in geneva

We introduce equivariant localization as a method for computing the action of probe branes in supergravity backgrounds. We apply it to supersymmetric probe D3-branes in type IIB supersymmetric spacetimes obtained by uplifting the Kerr-Newman-anti-de <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>Sitter</mi></mrow><mrow><mn>5</mn></mrow></msub></mrow></math> black hole on a toric Sasaki-Einstein space. Depending on the cycles they wrap, such branes represent nonperturbative corrections to or defect operator insertions in the superconformal index of a large family of four-dimensional <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">N</mi><mo>=</mo><mn>1</mn></math> quiver superconformal field theories. The resulting action reduces to equivariant integrals and can be evaluated entirely from toric data.

Pietro Benetti Genolini

Christopher Couzens

Alice Lüscher

Probing black holes with equivariant localization

I present a unified model for single pion production in photo-, electro-, and neutrino-nucleon interactions that is applicable across the broad kinematic range in the GeV regime relevant to accelerator-based neutrino experiments. The model incorporates vector and axial-vector transition form factors for excited nucleon states with masses up to 2 GeV, together with nonresonant background contributions, within a meson dominance framework that respects quantum chromodynamic constraints and preserves unitarity. This construction ensures the correct asymptotic behavior at large momentum transfer (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>Q</mi><mn>2</mn></msup></math>) while providing a consistent description of the resonance and transition regions. At very low <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>Q</mi><mn>2</mn></msup></math>, the implementation of the conserved vector current and partially conserved axial current relations leads to reliable predictions and helps address challenges encountered in current neutrino data analyses. The unified framework enables a global analysis that combines the available electron, photon, pion, and neutrino scattering data. This comprehensive approach allows detailed studies of nucleon structure in the resonance region and provides important constraints on weak interaction form factors, where modern neutrino-nucleon data remain limited. By determining all model parameters simultaneously with their correlated uncertainties, the approach establishes a robust, data-driven foundation for precision neutrino interaction modeling in support of next-generation neutrino oscillation measurements.

M. Kabirnezhad

Single pion production off free nucleons: Analysis of photon-, electron-, pion-, and neutrino-induced processes

We study top-antitop pair production in proton-proton collisions within the Standard Model effective field theory (SMEFT) at dimension six. We focus on the top chromomagnetic operator <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>C</mi><mrow><mi>t</mi><mi>G</mi></mrow></msub></math> together with the four-quark operators relevant for unpolarized <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>t</mi><mover accent="true"><mi>t</mi><mo stretchy="false">¯</mo></mover></math> production. We analyze the top-quark single-differential transverse-momentum (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>p</mi><mi>T</mi></msub></math>) and rapidity (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>y</mi></math>) distributions and the double-differential distributions in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>p</mi><mi>T</mi></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>y</mi></math> (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>p</mi><mi>T</mi></msub><mo>×</mo><mi>y</mi></math>) at 13 TeV, and we present projections for 13.6 TeV using the same binning. Our highest-order setup combines next-to-next-to-leading-order (NNLO) Standard Model (SM) predictions with approximate NNLO SM-SMEFT interference corrections. We find that higher-order QCD effects are essential for a stable SMEFT interpretation, yielding substantially more robust bounds and milder parameter degeneracies. The strongest sensitivity is obtained for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>C</mi><mrow><mi>t</mi><mi>G</mi></mrow></msub></math>. In the combined highest-order analysis of the 13-TeV results and 13.6-TeV projections, we obtain sensitivity to effective scales up to 3.9 TeV. Our results show that higher-order differential top-pair production provides a precise and theoretically controlled probe of the top chromomagnetic interaction.

Nikolaos Kidonakis

Kaan Şimşek

<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>t</mi><mover accent="true"><mi>t</mi><mo stretchy="false">¯</mo></mover></math> production as a probe of dimension-six SMEFT at higher orders

We deploy quantum chromodynamics in light-front quantization (and gauge), discretized and truncated in both Fock and momentum spaces with a particle-register encoding suited for quantum simulation; we show for the first time how to calculate fragmentation functions, a problem heretofore untractable in general from ab initio approaches. We provide a classical-simulator-based proof of concept by computing the charm-to-charmonium fragmentation, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>c</mi><mo stretchy="false">→</mo><mi>J</mi><mo>/</mo><mi>ψ</mi></math>, in a simplified setup, an interesting case where we can (reasonably) compare with the known 1993 perturbative evaluation (and a more recent one at next-to-leading order) within nonrelativistic QCD.