We systematically investigate theoretical uncertainties in perturbative analyses of first-order electroweak phase transitions (EWPTs). Utilizing the Standard Model effective field theory framework, we quantify the gauge dependence, renormalization scheme, and scale dependencies in predicting phase-transition parameters across both zero and finite chemical potential regimes. Our key findings reveal that: (1) The gauge-parameter dependence and the chemical potential are subdominant, and (2) Baryon number preservation criteria and phase transition observables exhibit pronounced sensitivity to the renormalization scale in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mover accent="true"><mi>MS</mi><mo stretchy="true">¯</mo></mover></math> scheme. Comparative analyses with the on-shell scheme demonstrate that within strongly first-order EWPT parameter spaces, the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mover accent="true"><mi>MS</mi><mo stretchy="true">¯</mo></mover></math> scheme predicts enhanced phase transition strengths and prolonged transition durations.

China

Yongzhao Zhu

Jie Liu

Renhui Qin

Ligong Bian

Theoretical uncertainties in first-order electroweak phase transitions

An important theoretical achievement of the last century was the realization that strict renormalizability can be a powerful criterion to select Lagrangians in the framework of perturbative quantum field theory. The Standard Model Lagrangian (without gravity) is strictly renormalizable from a perturbative point of view. On the other hand, the inclusion of gravity seems not to respect this criterion, since general relativity is perturbatively non-renormalizable. The aim of this work is to provide concrete evidence that strict renormalizability is still a valid criterion even when applied to gravity. First, we show that adding quadratic curvature terms to the Einstein-Hilbert action gives rise to a strictly renormalizable theory known as quadratic gravity. Second, we argue that this unique theory represents the most conservative approach to quantum gravity and, at the same time, is highly predictive, as it can explain new physics beyond general relativity already in the sub-Planckian regime. In particular, it provides one of the best fits to the CMB anisotropies via Starobinsky inflation and makes sharp cosmological predictions that can be tested in the near future. Finally, we comment on the (super-)Planckian regime and conclude with a historical note.

Netherlands

Luca Buoninfante

Strict renormalizability as a paradigm for fundamental physics

A measurement of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mrow><mi>W</mi></mrow><mi>Z</mi><mi>γ</mi></mrow></math> triboson production cross section is presented. The analysis is based on a data sample of proton-proton collisions at a center-of-mass energy of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msqrt><mi>s</mi></msqrt><mo>=</mo><mn>13</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></math> recorded with the CMS detector at the LHC, corresponding to an integrated luminosity of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>138</mn><mtext> </mtext><mtext> </mtext><msup><mi>fb</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math>. The analysis focuses on the final state with three charged leptons, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mrow><msup><mrow><mo>ℓ</mo></mrow><mrow><mo>±</mo></mrow></msup></mrow><mi>ν</mi><mrow><msup><mrow><mo>ℓ</mo></mrow><mrow><mo>+</mo></mrow></msup></mrow><mrow><msup><mrow><mo>ℓ</mo></mrow><mrow><mo>−</mo></mrow></msup></mrow></mrow></math>, where <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo>ℓ</mo><mo>=</mo><mi>e</mi></math> or <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>μ</mi></mrow></math>, accompanied by an additional photon. The observed (expected) significance of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>W</mi></mrow><mi>Z</mi><mrow><mi>γ</mi></mrow></math> signal is 5.4 (3.8) standard deviations. The cross section is measured in a fiducial region, where events with an ℓ originating from a tau lepton decay are excluded, to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>5.48</mn><mo>±</mo><mn>1.11</mn><mtext> </mtext><mtext> </mtext><mi>fb</mi></math>, which is compatible with the prediction of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>3.69</mn><mo>±</mo><mn>0.24</mn><mtext> </mtext><mtext> </mtext><mi>fb</mi></math> at next-to-leading order in quantum chromodynamics. Exclusion limits are set on anomalous quartic gauge couplings and on the production cross sections of massive axionlike particles.

Armenia

V. Chekhovsky

A. Hayrapetyan

V. Makarenko

A. Tumasyan

Austria

W. Adam

J.W. Andrejkovic

L. Benato

T. Bergauer

S. Chatterjee

K. Damanakis

M. Dragicevic

P.S. Hussain

M. Jeitler

N. Krammer

A. Li

D. Liko

I. Mikulec

J. Schieck

R. Schöfbeck

D. Schwarz

M. Sonawane

W. Waltenberger

C.E. Wulz

Belgium

T. Janssen

H. Kwon

T. Van Laer

P. Van Mechelen

N. Breugelmans

J. D’Hondt

S. Dansana

A. De Moor

M. Delcourt

F. Heyen

Y. Hong

S. Lowette

I. Makarenko

D. Müller

S. Tavernier

M. Tytgat

G.P. Van Onsem

S. Van Putte

D. Vannerom

B. Bilin

B. Clerbaux

A.K. Das

I. De Bruyn

G. De Lentdecker

H. Evard

L. Favart

P. Gianneios

A. Khalilzadeh

F.A. Khan

A. Malara

M.A. Shahzad

L. Thomas

M. Vanden Bemden

C. Vander Velde

P. Vanlaer

M. De Coen

D. Dobur

G. Gokbulut

J. Knolle

L. Lambrecht

D. Marckx

K. Skovpen

N. Van Den Bossche

J. van der Linden

J. Vandenbroeck

L. Wezenbeek

S. Bein

A. Benecke

A. Bethani

G. Bruno

C. Caputo

J. De Favereau De Jeneret

C. Delaere

I.S. Donertas

A. Giammanco

A.O. Guzel

Sa. Jain

V. Lemaitre

J. Lidrych

P. Mastrapasqua

T.T. Tran

S. Turkcapar

Brazil

G.A. Alves

E. Coelho

G. Correia Silva

C. Hensel

T. Menezes De Oliveira

C. Mora Herrera

P. Rebello Teles

M. Soeiro

E.J. Tonelli Manganote

A. Vilela Pereira

W.L. Aldá Júnior

M. Barroso Ferreira Filho

H. Brandao Malbouisson

W. Carvalho

J. Chinellato

Observation of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>W</mi><mi>Z</mi><mi>γ</mi></math> production and constraints on new physics scenarios in proton-proton collisions at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msqrt><mi>s</mi></msqrt><mo>=</mo><mn>13</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></math>

United States

Samuel Ting

Discovery of the J particle at Brookhaven National Laboratory and the physics of electrons and positrons

Cosmic strings are powerful witnesses to cosmic events including any period of early matter domination. If such a period of matter domination was catalyzed by metastable, long-lived particles, then there will be complementary signals to ascertain the nature of the dark sector in experiments detecting primordial features in the gravitational wave (GW) power spectrum and laboratory searches for long-lived particles. We give explicit examples of global and local <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>U</mi><mo stretchy="false">(</mo><mn>1</mn><mo stretchy="false">)</mo></math> gauge extended dark sectors to demonstrate such a complementarity as the union of the two experiments reveals more information about the dark sector than either experiment. Demanding that Higgs-portal long-lived scalar be looked for, in various experiments such as DUNE, FASER, FASER-II, MATHUSLA, and SHiP, we identify the parameter space that leads to complementary observables for GW detectors such as the Laser Interferometer Space Antenna and Einstein Telescope.

Satyabrata Datta

India

Ambar Ghosal

Poland

Anish Ghoshal

United Kingdom

Graham White

Complementarity between cosmic string gravitational waves and long-lived particle searches in a laboratory

Coherent elastic neutrino-nucleus scattering (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>CE</mi><mi>ν</mi><mi>NS</mi></mrow></math>) is a key process for probing Standard Model and beyond the Standard Model (BSM) properties. Following its first detection by the COHERENT Collaboration, recent reactor-based experiments provide a unique opportunity to refine our current understanding. In particular, the high-precision data from <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>CONUS</mi><mo>+</mo></mrow></math>, combined with the strong bounds from TEXONO, not only validate the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>CE</mi><mi>ν</mi><mi>NS</mi></mrow></math> process at low energies but also provide improved constraints on the weak mixing angle, neutrino electromagnetic properties (including the charge radius, millicharge, and magnetic moment), and nonstandard interactions and light mediators. We also examine the role of elastic neutrino-electron scattering, which gains significance in certain BSM scenarios and allows us to obtain the best limit for the millicharge of the electron neutrinos. By combining reactor and higher-energy spallation neutron source measurements, this work strengthens <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>CE</mi><mi>ν</mi><mi>NS</mi></mrow></math> as a precision tool for testing the Standard Model and beyond.

Italy

M. Atzori Corona

M. Cadeddu

N. Cargioli

F. Dordei

C. Giunti

Reactor antineutrinos <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>CE</mi><mi>ν</mi><mi>NS</mi></mrow></math> on germanium: <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>CONUS</mi><mo>+</mo></mrow></math> and TEXONO as a new gateway to SM and BSM physics

We study the scattering of the gluon-dressed physical quarks, defined as the eigenstates of the vacuum QCD Hamiltonian, off a colored medium. We solve the wave function of the physical quark state by diagonalizing the QCD Hamiltonian in vacuum in a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">|</mo><mi>q</mi><mo stretchy="false">⟩</mo><mo>+</mo><mo stretchy="false">|</mo><mrow><mi>q</mi><mi>g</mi></mrow><mo stretchy="false">⟩</mo></math> Fock space, with implementing the sector-dependent mass renormalization scheme. We then perform numerical simulations of the real-time quantum state evolution of the initially dressed quark state at various medium densities. The results are compared with those of an initially bare or off-shell quark states. With the obtained light-front wave function of the evolved state, we extract the quark jet transverse momentum broadening, the quenching parameter, the cross section, the gluon emission rate, and the evolution of the invariant mass. The scenario considered is relevant for high energy scattering processes, where the quark originates from far outside the color field describing the scattering target. This investigation on dressed quarks complements our earlier studies of the single quark scattering in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">|</mo><mi>q</mi><mo stretchy="false">⟩</mo></math> Fock space, and of the bare quark scattering in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">|</mo><mi>q</mi><mo stretchy="false">⟩</mo><mo>+</mo><mo stretchy="false">|</mo><mrow><mi>q</mi><mi>g</mi></mrow><mo stretchy="false">⟩</mo></math> Fock space, providing a novel systematic description of quark scattering process using a nonperturbative formalism.

Spain

Meijian Li

Finland

Tuomas Lappi

Xingbo Zhao

Carlos A. Salgado

Scattering and gluon emission of physical quarks in a SU(3) colored field

We propose a new machine-learning-based anomaly detection strategy for comparing data with a background-only reference (a form of weak supervision). The sensitivity of previous strategies degrades significantly when the signal is too rare or there are many unhelpful features. Our prior-assisted weak supervision (PAWS) method incorporates information from a class of signal models to significantly enhance the search sensitivity of weakly supervised approaches. As long as the true signal is in the prespecified class, PAWS matches the sensitivity of a dedicated, fully supervised method without specifying the exact parameters ahead of time. On the benchmark LHC Olympics anomaly detection dataset, our mix of semisupervised and weakly supervised learning is able to extend the sensitivity over previous methods by a factor of 10 in cross section. Furthermore, if we add irrelevant (noise) dimensions to the inputs, classical methods degrade by another factor of 10 in cross section while PAWS remains insensitive to noise. This new approach could be applied in a number of scenarios and pushes the frontier of sensitivity between completely model-agnostic approaches and fully model-specific searches.

Chi Lung Cheng

Gup Singh

Benjamin Nachman

Incorporating Physical Priors into Weakly Supervised Anomaly Detection

We use lattice QCD calculations of the finite-volume spectra of systems of two and three mesons to determine, for the first time, three-particle scattering amplitudes with physical quark masses. Our results are for combinations of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>π</mi></mrow><mrow><mo>+</mo></mrow></msup></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>K</mi><mo>+</mo></msup></math>, at a lattice spacing <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>a</mi><mo>=</mo><mn>0.063</mn><mtext> </mtext><mtext> </mtext><mi>fm</mi></mrow></math>, and in the isospin-symmetric limit. We also obtain accurate results for maximal-isospin two-meson amplitudes, with those for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>π</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>K</mi></mrow><mrow><mo>+</mo></mrow></msup></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>2</mn><msup><mrow><mi>K</mi></mrow><mrow><mo>+</mo></mrow></msup></mrow></math> being the first determinations at the physical point. Dense lattice spectra are obtained using the stochastic Laplacian-Heaviside method, and the analysis leading to scattering amplitudes is done using the relativistic finite-volume formalism. Results are compared to chiral perturbation theory and to phenomenological fits to experimental data, finding good agreement.

Sebastian M. Dawid

Zachary T. Draper

Andrew D. Hanlon

Germany

Ben Hörz

Colin Morningstar

Switzerland

Fernando Romero-López

Stephen R. Sharpe

Sarah Skinner

QCD Predictions for Physical Multimeson Scattering Amplitudes

We study systems of two and three mesons composed of pions and kaons at maximal isospin using four CLS ensembles with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>a</mi><mo>≈</mo><mn>0.063</mn><mtext> </mtext><mtext> </mtext><mi>fm</mi></math>, including one with approximately physical quark masses. Using the stochastic Laplacian-Heaviside method, we determine the energy spectrum of these systems including many levels in different momentum frames and irreducible representations. Using the relativistic two- and three-body finite-volume formalism, we constrain the two- and three-meson K matrices, including not only the leading <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>s</mi></math> wave, but also <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>d</mi></math> waves. By solving the three-body integral equations, we determine, for the first time, the physical-point scattering amplitudes for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>3</mn><msup><mi>π</mi><mo>+</mo></msup></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>3</mn><msup><mi>K</mi><mo>+</mo></msup></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>π</mi><mo>+</mo></msup><msup><mi>π</mi><mo>+</mo></msup><msup><mi>K</mi><mo>+</mo></msup></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>K</mi><mo>+</mo></msup><msup><mi>K</mi><mo>+</mo></msup><msup><mi>π</mi><mo>+</mo></msup></math> systems. These are determined for total angular momentum <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>J</mi><mi>P</mi></msup><mo>=</mo><msup><mn>0</mn><mo>−</mo></msup></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mn>1</mn><mo>+</mo></msup></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mn>2</mn><mo>−</mo></msup></math>. We also obtain accurate results for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2</mn><msup><mi>π</mi><mo>+</mo></msup></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>π</mi><mo>+</mo></msup><msup><mi>K</mi><mo>+</mo></msup></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2</mn><msup><mi>K</mi><mo>+</mo></msup></math> phase shifts. We compare our results to chiral perturbation theory and to phenomenological fits.

Two- and three-meson scattering amplitudes with physical quark masses from lattice QCD