We study oscillon/<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>I</mi></mrow></math>-ball solutions in a real scalar version of the Friedberg-Lee-Sirlin model. Using the multiple-scale analysis, we derive the conditions for oscillon solutions and explore multifield oscillon configurations. In these configurations, the two fields form colocated oscillons that oscillate with frequencies set by their respective masses. These multifield oscillons can be viewed as a bound state of two oscillons due to attractive interactions between the fields. We confirm these analytical predictions through numerical lattice calculations. This work extends the standard picture of single-field oscillons and may be relevant for cosmological scenarios involving multiple interacting real scalar fields.

Japan

Kai Murai

Tatsuya Ogawa

Fuminobu Takahashi

Multifield oscillons/<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>I</mi></mrow></math>-balls in the Friedberg-Lee-Sirlin model

The analytic structure of the partition function in finite-volume systems is investigated at complex chemical potentials in a minimal mean-field effective model of QCD with finite-size effects incorporated. We discuss the temperature dependence of the Lee-Yang zeros and their relation to the edge singularity for various system sizes. Different methods for locating the critical point based on finite-size scaling of Lee-Yang zeros and susceptibility ratios are compared. We demonstrate that these methods can successfully identify the critical point, whereas a careful treatment of corrections from irrelevant operators is crucial for its accurate determination.

Tatsuya Wada

Poland

Hungary

Győző Kovács

Masakiyo Kitazawa

Takahiro M. Doi

Lee-Yang zeros and edge singularity in a mean-field approach

We present a unified description of the low-lying <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1</mn><mi>P</mi></math>- and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2</mn><mi>S</mi></math>-wave nucleon resonance within the framework of an extended Lee-Friedrichs scheme. By incorporating the coupled-channel dynamics between bare quark-model states and the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>π</mi><mi>N</mi></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>π</mi><mi mathvariant="normal">Δ</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>η</mi><mi>N</mi></math> meson-baryon continua, we examine the mass shifts and structural properties of these excited states. We demonstrate that when the model parameters are calibrated to match the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1</mn><mi>P</mi></math>-wave spectrum and their widths, the pole associated with the bare <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2</mn><mi>S</mi></math> state is naturally shifted downward to the mass region of physical Roper resonance–<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi><mo stretchy="false">(</mo><mn>1440</mn><mo stretchy="false">)</mo></math>, thereby offering a dynamical explanation for the long-standing level-inversion problem. An approximate analysis of compositeness and elementariness reveals that the Roper resonance contains a significant meson-baryon continuum states, consistent with the picture of a bare core heavily dressed by meson-baryon cloud. Simultaneously, the pole positions and properties of five <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1</mn><mi>P</mi></math>-wave resonances–<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi><mo stretchy="false">(</mo><mn>1535</mn><mo stretchy="false">)</mo></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi><mo stretchy="false">(</mo><mn>1650</mn><mo stretchy="false">)</mo></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi><mo stretchy="false">(</mo><mn>1520</mn><mo stretchy="false">)</mo></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi><mo stretchy="false">(</mo><mn>1700</mn><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi><mo stretchy="false">(</mo><mn>1675</mn><mo stretchy="false">)</mo></math>—are successfully reproduced. Our results highlight the essential role of coupled-channel effects in shaping the nucleon spectrum and provide a consistent microscopic insight into the interplay between internal quark degrees of freedom and external hadronic fields.

China

Yu-Hui Zhou

Hui-Hua Zhong

Zhi-Yong Zhou

Xian-Hui Zhong

Understanding the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>1</mn><mi>P</mi></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>2</mn><mi>S</mi></mrow></math> nucleon resonances within the extended Lee-Friedrichs model

The multicritical generalizations of the Lee-Yang universality class arise as renormalization-group fixed points of scalar field theories with complex $\textit{iφ}$ interaction, $\textit{n}$ ∈ ℕ, just below their upper critical dimension. It has been recently conjectured that their continuation to two dimensions corresponds to the non-unitary conformal minimal models ℳ(2$\textit{,}$ 2$\textit{n}$ + 3). Motivated by that, we revisit the functional renormalization group approach to complex 𝒫𝒯-symmetric scalar field theories in the Local Potential Approximation, without or with wavefunction renormalization (LPA and LPA’ respectively), aiming to explore the fate of the $\textit{iφ}$ theories from their upper critical dimension to two dimensions. The $\textit{iφ}$ fixed points are identified using a perturbative expansion of the functional fixed-point equation near their upper critical dimensions, and they are followed to lower dimensions by numerical integration of the full equation. A peculiar feature of the complex 𝒫𝒯-symmetric potentials is that the fixed points are characterized by real but negative anomalous dimensions $\textit{η}$, and in low dimension $\textit{d}$, this can lead to a change of sign of the scaling dimensions ∆ = ($\textit{d}$ − 2 + $\textit{η}$)$\textit{/}$2, thus requiring a novel analysis of the analytical properties of the functional fixed-point equations. We are able to follow the Lee-Yang universality class ($\textit{n}$ = 1) down to two dimensions, and numerically determine the scaling dimension of the fundamental field as a function of $\textit{d}$. On the other hand, within the LPA’, multicritical Lee-Yang fixed points with $\textit{n >}$ 1 cannot be continued to $\textit{d}$ = 2 due to the existence of unexpected non-perturbative fixed points that annihilate with the $\textit{iφ}$ fixed points.

France

Dario Benedetti

Fanny Eustachon

Italy

Omar Zanusso

Critical and multicritical Lee-Yang fixed points in the local potential approximation

Positive and negative flows of the Chen-Lee-Liu model and its various reductions, including Burgers hierarchy, are formulated within the framework of Riemann-Hilbert-Birkhoff decomposition with the constant grade two generator. Two classes of vacua, namely zero vacuum and constant non-zero vacuum can be realized within a centerless Heisenberg algebra. The tau functions for soliton solutions are obtained by a dressing method and vertex operators are constructed for both types of vacua. We are able to select and classify the soliton solutions in terms of the type of vertices involved. A judicious choice of vertices yields in a closed form a particular set of multi soliton solutions for the Burgers hierarchy. We develop and analyze a class of gauge-Bäcklund transformations that generate further multi soliton solutions from those obtained by dressing method by letting them interact with various integrable defects.

Brazil

Ireland

Y.F. Adans

United States

H. Aratyn

C.P. Constantinidis

J.F. Gomes

G.V. Lobo

T.C. Santiago

New soliton solutions for Chen-Lee-Liu and Burgers hierarchies and its Bäcklund transformations

We have performed high-statistics lattice simulations using 4HEX improved staggered fermions on <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mn>16</mn><mn>3</mn></msup><mo>×</mo><mn>8</mn></math> lattices. We calculated the Taylor expansion coefficients of the pressure with respect to the baryochemical potential to the tenth order at zero and the fourth order at purely imaginary chemical potentials. We used this data to construct rational function approximations of the free energy. We use a rational ansatz that explicitly satisfies the charge conjugation symmetry and the Roberge-Weiss periodicity, which are exact properties of the quantum chromodynamics free energy. We use this ansatz to estimate the position of Lee-Yang zeros in the complex chemical potential plane. The temperature dependence of the imaginary part of the Lee-Yang zeros is then fitted with ansätze motivated by the universal behavior of the free energy near a 3D Ising critical point. In principle, this allows one to estimate the temperature of the critical endpoint. We consider several sources of systematic errors. On this single lattice spacing, we find that with 84% probability the chiral critical endpoint is either below 103 MeV temperature or it does not exist. We also identify some caveats of the method, which do not disappear even with the extremely high statistics of this present study. We discuss to what extent these can be eliminated by future high statistics lattice analyses.

Germany

Alexander Adam

Szabolcs Borsányi

Zoltán Fodor

Jana N. Guenther

Piyush Kumar

Paolo Parotto

Attila Pásztor

Chik Him Wong

High-precision baryon number cumulants from lattice QCD in a finite box: Cumulant ratios, Lee-Yang zeros, and critical endpoint predictions

We investigate the QCD phase diagram and the associated Lee–Yang edge singularities using the two-flavor nonlocal Nambu–Jona-Lasinio model extended to complex chemical potential. We show explicitly there exists a strong correlation between the chiral phase transition and the patterns in the effective potential in the complex plane of order parameter, serving as a criterion to differentiate crossover from first-order transitions. Typically, the Lee–Yang edge singularities can be understood as a generalization of the critical end point (CEP) separating the crossover and the first-order transition, where the positive Nambu phase and the Wigner phase coalesce. We further analyze the scaling behavior near the CEP by extracting the critical exponent associated with the Lee–Yang singularities. Additionally, we confirm that the extrapolation of the Lee–Yang edge singularity trajectories provides an efficient method of determining the CEP location, even at a small real chemical potential. This provides a viable method for exploring regions of the QCD phase diagram that remain inaccessible to lattice QCD.

Zong-shuai Zhang

Yi Lu

Yu-xin Liu

Lee-Yang edge singularities in a nonlocal Nambu–Jona-Lasinio model

The Jiangmen Underground Neutrino Observatory (JUNO) started physics data taking on 26 August 2025. JUNO consists of a 20-kton liquid scintillator central detector, surrounded by a 35 kton water pool serving as a Cherenkov veto, and almost 1000 m$^{2}$ of plastic scintillator veto on top. The detector is located in a shallow underground laboratory with an overburden of 1800 m.w.e. This paper presents the performance results of the detector, extensively studied during the commissioning of the water phase, the subsequent liquid scintillator filling phase, and the first physics runs. The liquid scintillator achieved an attenuation length of 20.6 m at 430 nm, while the high coverage PMT system and scintillator together yielded about 1785 photoelectrons per MeV of energy deposit at the detector centre, measured using the 2.223 MeV $\textit{γ}$ from neutron captures on hydrogen with an Am-C calibration source. The reconstructed energy resolution is 3.4% for two 0.511 MeV $\textit{γ}$ at the detector centre and 2.9% for the 0.93 MeV quenched $^{214}$Po alpha decays from natural radioactive sources. The energy non-linearity is calibrated to better than 1%. Intrinsic contaminations of $^{238}$U and $^{232}$Th in the liquid scintillator are below 10$^{-16}$ g/g, assuming secular equilibrium. The water Cherenkov detector achieves a muon detection efficiency better than 99.9% for muons traversing the liquid scintillator volume. During the initial science runs, the data acquisition duty cycle exceeded 97.8%, demonstrating the excellent stability and readiness of JUNO for high-precision neutrino physics.

Chile

Angel Abusleme

Thomas Adam

Kai Adamowicz

David Adey

Pakistan

Shakeel Ahmad

Rizwan Ahmed

Finland

Timo Ahola

Sebastiano Aiello

Fengpeng An

Guangpeng An

United Kingdom

Costas Andreopoulos

Giuseppe Andronico

João Pedro Athayde Marcondes de André

Russia

Nikolay Anfimov

Vito Antonelli

Tatiana Antoshkina

Thailand

Burin Asavapibhop

Didier Auguste

Margherita Buizza Avanzini

Slovakia

Andrej Babic

Jingzhi Bai

Weidong Bai

Nikita Balashov

Roberto Barbera

Andrea Barresi

Davide Basilico

Eric Baussan

Beatrice Bellantonio

Marco Bellato

JeanLuc Beney

Marco Beretta

Antonio Bergnoli

Enrico Bernieri

Nikita Bessonov

David Biaré

Daniel Bick

Lukas Bieger

Svetlana Biktemerova

Thilo Birkenfeld

David Blum

Simon Blyth

Sara Boarin

Manuel Boehles

Anastasia Bolshakova

Mathieu Bongrand

Aurélie Bonhomme

Clément Bordereau

Matteo Borghesi

Augusto Brigatti

Timothee Brugiere

Riccardo Brugnera

Riccardo Bruno

Jonas Buchholz

Antonio Budano

Max Buesken

Mario Buscemi

Severino Bussino

Jose Busto

Ilya Butorov

Marcel Büchner

Anatael Cabrera

Barbara Caccianiga

Boshuai Cai

Hao Cai

Xiao Cai

Yanke Cai

Yi-zhou Cai

Zhiyan Cai

Stéphane Callier

Steven Calvez

Antonio Cammi

Agustin Campeny

Dechang Cai

Chuanya Cao

Dewen Cao

Guofu Cao

Jun Cao

Yaoqi Cao

Rossella Caruso

Aurelio Caslini

Cédric Cerna

Vanessa Cerrone

Daniele Cesini

Chi Chan

Jinfan Chang

Yun Chang

Milo Charavet

Tim Charissé

Auttakit Chatrabhuti

Chao Chen

Guoming Chen

Haitao Chen

Haotian Chen

Jiahui Chen

Jian Chen

Jing Chen

Junyou Chen

Lihao Chen

Mali Chen

Mingming Chen

Initial performance results of the JUNO detector * We acknowledge financial and institutional supportfrom the Chinese Academy of Sciences, the National KeyR&D Program of China, the People's Government of Guangdong Province, and the Tsung–Dao Lee Institute of Shanghai Jiao Tong University in China.We appreciate the contributions from the Institut Na-tional de Physique Nucléaire et de Physique des Partic-ules (IN2P3) in France, the Istituto Nazionale di Fisica Nucleare (INFN) in Italy, the Fonds de la Recherche Sci-entifique (F.R.S.–FNRS) and the Institut Interuni-versitaire des Sciences Nucléaires (IISN) in Belgium, and the Conselho Nacional de Desenvolvimento Científico eTecnológico (CNPq) in Brazil.We also acknowledge the support of the AgenciaNacional de Investigación y Desarrollo (ANID) and the ANID–Millennium Science Initiative Program (ICN2019044) in Chile; the European Structural and In-vestment Funds, the Ministry of Education, Youth and Sports, and the Charles University Research Center inthe Czech Republic; the Deutsche Forschungsgemeinsch-aft (DFG), the Helmholtz Association, and the Cluster ofExcellence PRISMA+ in Germany; and the Joint Insti-tute for Nuclear Research (JINR) and Lomonosov Mo-scow State University in Russia.We further thank the Slovak Research and Develop-ment Agency in the Slovak Republic, the National Science and Technology Council (NSCT) and MOE, China, the Program Management Unit for Hu-man Resources & Institutional Development, Research and Innovation (PMU–B), Chulalongkorn University, and Suranaree University of Technology in Thailand, the Science and Technology Facilities Council (STFC) in the United Kingdom, and the University of California atIrvine and the National Science Foundation (NSF) in the United States

The Lee–Wick pseudo-quantum electrodynamics in the presence of a Chern–Simons term is studied in this paper. The paper starts with a non-local lagrangian density that sets the pseudo-Lee–Wick electrodynamics defined on a $$1+2$$ space-time added to a non-local Chern–Simons topological term. Thus, we obtain the Lee–Wick–Chern–Simons pseudo-electrodynamics as a most complete gauge invariant model that provides a light mass associated with the Chern–Simons parameter, and also includes a Lee–Wick heavy mass. We investigate classical aspects as the potential energy for the interaction of static charges through the gauge propagator. The causality of theory is discussed through the retarded Green function in the coordinate space. The gauge field of the Lee–Wick–Chern–Simons pseudo-electrodynamics is minimally coupled to the fermions sector that includes new degree of freedoms, as a Lee–Wick heavy fermion partner of the electron. The perturbative approach for the theory is presented via effective action in which we obtain the Ward identities. We study the quantum corrections at one loop, as the electron self-energy, the vacuum polarization, and the 3-vertex. We show that the Lee–Wick mass has a fundamental role in these results, where it works like a natural regulator of the ultraviolet divergences. The $$g-2$$ factor for the electron is obtained as function of the LW mass, and of the CS parameter. Through the optical theorem, the Lee–Wick–Chern–Simons pseudo-electrodynamics is unitary at the tree level.

M. Neves

The Lee–Wick–Chern–Simons pseudo-quantum electrodynamics

We accomplish the Batalin-Fradkin-Vilkovisky (BFV) quantization of the Christ-Lee model in both polar and Cartesian coordinates. We construct the BRST charge along with gauge-fixing function and obtain the BRST invariant effective action. We also procure the finite field-dependent BRST (FFBRST) symmetries of the model. Finally, we obtain a generalized action of the model with finite field-dependent parameter. Thus, we bridge the BFV-BRST gauge-fixed action and the gauge-invariant classical action of the model using FFBRST transformations.